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WO2009123325A1 - Process for producing silicon nitride film, process for producing silicon nitride film laminate, computer-readable storage medium, and plasma cvd device - Google Patents

Process for producing silicon nitride film, process for producing silicon nitride film laminate, computer-readable storage medium, and plasma cvd device Download PDF

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Publication number
WO2009123325A1
WO2009123325A1 PCT/JP2009/057006 JP2009057006W WO2009123325A1 WO 2009123325 A1 WO2009123325 A1 WO 2009123325A1 JP 2009057006 W JP2009057006 W JP 2009057006W WO 2009123325 A1 WO2009123325 A1 WO 2009123325A1
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WO
WIPO (PCT)
Prior art keywords
gas
silicon
flow rate
silicon nitride
range
Prior art date
Application number
PCT/JP2009/057006
Other languages
French (fr)
Japanese (ja)
Inventor
本多稔
中西敏雄
鴻野真之
西田辰夫
宮原準弥
Original Assignee
東京エレクトロン株式会社
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Priority claimed from JP2008092418A external-priority patent/JP2009246210A/en
Priority claimed from JP2009079530A external-priority patent/JP2009267391A/en
Application filed by 東京エレクトロン株式会社 filed Critical 東京エレクトロン株式会社
Priority to US12/935,138 priority Critical patent/US8119545B2/en
Publication of WO2009123325A1 publication Critical patent/WO2009123325A1/en

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Classifications

    • C—CHEMISTRY; METALLURGY
    • C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
    • C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
    • C23C16/00—Chemical coating by decomposition of gaseous compounds, without leaving reaction products of surface material in the coating, i.e. chemical vapour deposition [CVD] processes
    • C23C16/22—Chemical coating by decomposition of gaseous compounds, without leaving reaction products of surface material in the coating, i.e. chemical vapour deposition [CVD] processes characterised by the deposition of inorganic material, other than metallic material
    • C23C16/30—Deposition of compounds, mixtures or solid solutions, e.g. borides, carbides, nitrides
    • C23C16/34—Nitrides
    • C23C16/345—Silicon nitride
    • C—CHEMISTRY; METALLURGY
    • C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
    • C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
    • C23C16/00—Chemical coating by decomposition of gaseous compounds, without leaving reaction products of surface material in the coating, i.e. chemical vapour deposition [CVD] processes
    • C23C16/44—Chemical coating by decomposition of gaseous compounds, without leaving reaction products of surface material in the coating, i.e. chemical vapour deposition [CVD] processes characterised by the method of coating
    • C23C16/50—Chemical coating by decomposition of gaseous compounds, without leaving reaction products of surface material in the coating, i.e. chemical vapour deposition [CVD] processes characterised by the method of coating using electric discharges
    • C23C16/505—Chemical coating by decomposition of gaseous compounds, without leaving reaction products of surface material in the coating, i.e. chemical vapour deposition [CVD] processes characterised by the method of coating using electric discharges using radio frequency discharges
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L29/00—Semiconductor devices specially adapted for rectifying, amplifying, oscillating or switching and having potential barriers; Capacitors or resistors having potential barriers, e.g. a PN-junction depletion layer or carrier concentration layer; Details of semiconductor bodies or of electrodes thereof ; Multistep manufacturing processes therefor
    • H01L29/40—Electrodes ; Multistep manufacturing processes therefor
    • H01L29/43—Electrodes ; Multistep manufacturing processes therefor characterised by the materials of which they are formed
    • H01L29/49—Metal-insulator-semiconductor electrodes, e.g. gates of MOSFET
    • H01L29/51—Insulating materials associated therewith
    • H01L29/511—Insulating materials associated therewith with a compositional variation, e.g. multilayer structures
    • H01L29/513—Insulating materials associated therewith with a compositional variation, e.g. multilayer structures the variation being perpendicular to the channel plane
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L29/00—Semiconductor devices specially adapted for rectifying, amplifying, oscillating or switching and having potential barriers; Capacitors or resistors having potential barriers, e.g. a PN-junction depletion layer or carrier concentration layer; Details of semiconductor bodies or of electrodes thereof ; Multistep manufacturing processes therefor
    • H01L29/66—Types of semiconductor device ; Multistep manufacturing processes therefor
    • H01L29/68—Types of semiconductor device ; Multistep manufacturing processes therefor controllable by only the electric current supplied, or only the electric potential applied, to an electrode which does not carry the current to be rectified, amplified or switched
    • H01L29/76—Unipolar devices, e.g. field effect transistors
    • H01L29/772—Field effect transistors
    • H01L29/78—Field effect transistors with field effect produced by an insulated gate
    • H01L29/792—Field effect transistors with field effect produced by an insulated gate with charge trapping gate insulator, e.g. MNOS-memory transistors
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L21/00—Processes or apparatus adapted for the manufacture or treatment of semiconductor or solid state devices or of parts thereof
    • H01L21/02—Manufacture or treatment of semiconductor devices or of parts thereof
    • H01L21/02104—Forming layers
    • H01L21/02107—Forming insulating materials on a substrate
    • H01L21/02109—Forming insulating materials on a substrate characterised by the type of layer, e.g. type of material, porous/non-porous, pre-cursors, mixtures or laminates
    • H01L21/02112—Forming insulating materials on a substrate characterised by the type of layer, e.g. type of material, porous/non-porous, pre-cursors, mixtures or laminates characterised by the material of the layer
    • H01L21/02123—Forming insulating materials on a substrate characterised by the type of layer, e.g. type of material, porous/non-porous, pre-cursors, mixtures or laminates characterised by the material of the layer the material containing silicon
    • H01L21/0217—Forming insulating materials on a substrate characterised by the type of layer, e.g. type of material, porous/non-porous, pre-cursors, mixtures or laminates characterised by the material of the layer the material containing silicon the material being a silicon nitride not containing oxygen, e.g. SixNy or SixByNz
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L21/00—Processes or apparatus adapted for the manufacture or treatment of semiconductor or solid state devices or of parts thereof
    • H01L21/02—Manufacture or treatment of semiconductor devices or of parts thereof
    • H01L21/02104—Forming layers
    • H01L21/02107—Forming insulating materials on a substrate
    • H01L21/02225—Forming insulating materials on a substrate characterised by the process for the formation of the insulating layer
    • H01L21/0226—Forming insulating materials on a substrate characterised by the process for the formation of the insulating layer formation by a deposition process
    • H01L21/02263—Forming insulating materials on a substrate characterised by the process for the formation of the insulating layer formation by a deposition process deposition from the gas or vapour phase
    • H01L21/02271—Forming insulating materials on a substrate characterised by the process for the formation of the insulating layer formation by a deposition process deposition from the gas or vapour phase deposition by decomposition or reaction of gaseous or vapour phase compounds, i.e. chemical vapour deposition
    • H01L21/02274—Forming insulating materials on a substrate characterised by the process for the formation of the insulating layer formation by a deposition process deposition from the gas or vapour phase deposition by decomposition or reaction of gaseous or vapour phase compounds, i.e. chemical vapour deposition in the presence of a plasma [PECVD]

Definitions

  • the present invention relates to a method for producing a silicon nitride film and a laminate thereof,
  • Non-volatile semiconductor memory devices such as EEPR OM (E 1 ectrica 1 1 y E rasable and Programmable R OM) that can be electrically rewritten are currently S ONO S (S i 1 icon-O Some have a layered structure called the xide -N itride -O xide—S i 1 icon) type or the MONO S (Metal-O xide —N itride—O xide—S i 1 icon) type. In these types of non-volatile semiconductor memory devices, information is retained by using one or more silicon nitride films (Nitride) sandwiched between silicon dioxide films (O xide) as charge storage regions.
  • a voltage is applied between the semiconductor substrate (S i 1 icon) and the control gate electrode (S i 1 icon or M eta 1), thereby nitriding the charge storage region. Rewriting data storage and erasure by injecting electrons into the silicon film and storing data, or removing electrons accumulated in the silicon nitride film I'm doing it.
  • the charge storage capacity of silicon nitride film is thought to be related to its bandgap structure.
  • Patent Document 1 discloses that when forming a silicon nitride film between a tunnel oxide film and a top oxide film, dichlorosilane (S i H 2 C 1 2 ) and ammonia (NH 3 ) as source gas, flow rate ratio Si H 2 C 1 2 ZNH 3 is reduced to 1 Z 10 or less under reduced pressure CVD (Chemical Vapor Deposition) A method of forming a silicon nitride film formed by the deposition method is described. However, in the case of the conventional CVD deposition process, it was difficult to control the band gap of each silicon nitride film only by the process conditions.
  • the silicon nitride film is oxidized to change into a silicon nitride oxide film. It was necessary to change the components of the membrane itself.
  • a plurality of film forming apparatuses are required, and the process efficiency is lowered.
  • a silicon nitride film functioning as a charge storage region is formed as a laminate of two or more layers (silicon nitride film laminate)
  • a silicon nitride film is generally formed by a plasma C VD method, but the silicon nitride film produced by this method is often used as an etching hard mask stopper film. It was a high-quality silicon nitride film that was dense and had few defects.
  • Patent Document 1 Japanese Patent Application Laid-Open No. 5-1 4 5 0 78 (for example, paragraph 0 0 1 5 etc.) Disclosure of Invention
  • the present invention has been made in view of the above circumstances, and a first object thereof is to provide a method for manufacturing a silicon nitride film in which the size of the band gap can be easily controlled by the CVD method.
  • the second object of the present invention is to provide a method for easily manufacturing a silicon nitride film laminate by changing the band gap size of each silicon nitride film by the CVD method.
  • the method for producing a silicon nitride film of the present invention uses a plasma C VD apparatus that generates plasma by introducing microwaves into a processing chamber using a planar antenna having a plurality of holes, and uses a plasma C VD method on a workpiece.
  • the processing pressure is set constant within a range of 0.1 Pa to 1 3 3 3 Pa,
  • select the flow rate ratio between silicon-containing compound gas and nitrogen gas (silicon-containing compound gas flow rate Z nitrogen gas flow rate) within the range of 0.005 to 0.2.
  • the film-forming gas contains ammonia gas
  • the flow rate ratio between the silicon-containing compound gas and the ammonia gas (silicon-containing compound gas flow rate, ammonia gas flow rate) is within the range of 0.015 to 0.2.
  • Select, perform plasma CVD, and bandgap A C VD process for forming a silicon nitride film with a size in the range of 2.5 eV to 7 eV is provided.
  • the processing pressure may be set constant within a range of 0.1 l Pa to 4 Pa or 40 Pa to 1 3 3 3 Pa. preferable.
  • a high frequency is supplied to the object to be processed within a power density range of 0. Ol WZ cm 2 or more and 0.64 W / cm 2 or less.
  • the method for producing a silicon nitride film laminate of the present invention uses a plasma C VD apparatus that generates plasma by introducing microwaves into a processing chamber using a planar antenna having a plurality of holes, and the plasma C VD is formed on the object to be processed.
  • the processing pressure is set to a constant value within the range of 0.1 l Pa to 1 3 3 3 Pa,
  • the flow rate ratio between the silicon-containing compound gas and the nitrogen gas is selected from the range of 0.005 to 0.2.
  • the flow rate ratio between silicon-containing compound gas and ammonia gas is selected from the range of 0.0 1 5 or more and 0.2 or less Performing a plasma C VD, and forming a silicon nitride film having a first band gap in a range of 2.5 eV to 7 eV, Before or after the first CVD step, a film forming gas containing either nitrogen gas or ammonia gas and a silicon-containing compound gas is used, and the film forming gas is subjected to the same processing pressure as that in the first CVD step.
  • the first C VD process within a range of flow rate ratio between silicon-containing compound gas and nitrogen gas (silicon-containing compound gas flow rate / nitrogen gas flow rate) of 0.005 or more and 0.2 or less.
  • the flow ratio of silicon-containing compound gas to ammonia gas is not less than 0.0 1 5 0.2
  • the second band gap is different from the first band gap within the range of 2.5 eV or more and 7 eV or less by setting a range different from the first C VD process within the following range.
  • the computer-readable storage medium of the present invention is a computer-readable storage medium storing a control program that runs on a computer
  • the control program uses a plasma C VD apparatus in which a plasma is generated by introducing microwaves into a processing chamber by a planar antenna having a plurality of holes at the time of execution, and silicon nitride is formed on a workpiece by plasma C VD method.
  • a plasma C VD apparatus in which a plasma is generated by introducing microwaves into a processing chamber by a planar antenna having a plurality of holes at the time of execution, and silicon nitride is formed on a workpiece by plasma C VD method.
  • the processing pressure is set to a constant value within the range of 0.1 l Pa to 1 3 3 3 Pa
  • the flow rate ratio of silicon-containing compound gas and nitrogen gas is selected from the range of 0.005 or more and 0.2 or less
  • the film-forming gas contains ammonia gas
  • the flow rate ratio of silicon-containing compound gas and ammonia gas Select the compound gas flow rate (Z-ammonia gas flow rate) containing silicon from a range of 0.0 1 5 or more and 0.2 or less, perform plasma CVD, and the band gap size is 2.5 eV or more 7 eV
  • the plasma C VD apparatus is controlled by a computer so that a CVD process for forming a silicon nitride film within the following range is performed.
  • the plasma C VD apparatus of the present invention is a plasma C VD apparatus for forming a silicon nitride film on a workpiece by a plasma C VD method
  • a processing chamber for storing the object to be processed on the mounting table
  • a planar antenna provided outside the dielectric member and having a plurality of holes for introducing microwaves into the processing chamber;
  • a gas supply device for supplying a source gas into the processing chamber
  • the processing pressure is set constant within a range of 0.1 Pa to 1 3 3 3 Pa
  • the flow rate ratio of silicon-containing compound gas to nitrogen gas is selected from the range of 0.005 to 0.2
  • the deposition gas contains ammonia gas
  • select the flow rate ratio between silicon-containing compound gas and ammonia gas is selected within the range of 0.0 1 5 or more and 0.2 or less.
  • a film forming gas containing either nitrogen gas or ammonia gas and a silicon-containing compound gas is used, and the processing pressure is set to 0.1 l Pa or more 1 3 3 3
  • the flow rate ratio of silicon-containing compound gas to nitrogen gas is set to 0.0.
  • the flow rate ratio between silicon-containing compound gas and ammonia gas is set to 0.0 1 5
  • a silicon nitride film within a range of S 2.5 eV to 7 eV can be easily manufactured by performing plasma CVD by selecting from the range of 0.2 or more and less than 0.2. can do.
  • the size of the band gap can be easily controlled mainly by selecting the flow rate ratio of the source gas and the processing pressure, continuous film formation is required when forming a silicon nitride film laminate having various band gap structures. Is possible, and process efficiency is excellent.
  • FIG. 1 is a schematic cross-sectional view showing an example of a plasma CVD apparatus suitable for forming a silicon nitride film.
  • Figure 2 shows the structure of a planar antenna.
  • FIG. 3 is an explanatory diagram showing the configuration of the control unit.
  • FIG. 4A and FIG. 4B are drawings showing a process example of the method for manufacturing the silicon nitride film according to the first embodiment.
  • FIG. 5 is a graph showing the relationship between the silicon-containing compound gas Z-nitrogen gas ratio and the plasma gap in plasma C V D.
  • FIG. 6A to FIG. 6F are drawings showing a process example of the method for manufacturing the silicon nitride film laminate according to the second embodiment.
  • FIG. 7 is a schematic cross-sectional view showing another example of a plasma C VD apparatus suitable for forming a silicon nitride film.
  • FIG. 8A and FIG. 8B are drawings showing a process example of the method for manufacturing the silicon nitride film according to the third embodiment.
  • FIG. 9 is a graph showing the relationship between the output density of the RF bias and the band gap of the silicon nitride film according to the processing pressure.
  • FIG. 10 is a graph showing the relationship between the RF bias output density and the bandgap of the silicon nitride film for each Ar flow rate.
  • FIGS. 11A and 11B are drawings showing a process example of the method for manufacturing the silicon nitride film according to the fourth embodiment.
  • Figure 12 is a graph showing the relationship between the processing pressure and the band gap in plasma C V D.
  • FIGS. 13A to 13 F are drawings showing process steps of the method for manufacturing the silicon nitride film laminated body according to the fifth embodiment.
  • FIG. 14 is an explanatory diagram showing a schematic configuration of a MOS type semiconductor memory device to which the method of the present invention is applicable.
  • FIG. 1 is a cross-sectional view schematically showing a schematic configuration of a plasma C VD apparatus 100 that can be used in the method for producing a silicon nitride film of the present invention.
  • the plasma C VD apparatus 100 uses a flat antenna with a plurality of slot-shaped holes, especially RLSA (Radial Line Slot Antenna) to introduce microwaves into the processing chamber. It is configured as an RLSA microwave plasma processing device that can generate microwave-excited plasma with high density and low electron temperature by generating it. In the plasma C VD apparatus 100, it is possible to process with plasma having a plasma density of 1 X 1 0 1 Q to 5 X 10 12 / cm 3 and a low electron temperature of 0.7 to 2 e V . Accordingly, the plasma C VD apparatus 100 can be suitably used for the purpose of forming a silicon nitride film by plasma C VD in the manufacturing process of various semiconductor devices.
  • RLSA Random Line Slot Antenna
  • the plasma C VD apparatus 10 0 has, as main components, an airtight process vessel 1, a gas supply device 18 that supplies gas into the process vessel 1, and a vacuum exhaust in the process vessel 1.
  • the exhaust device 24, the microwave introduction mechanism 27 for introducing microwaves into the processing vessel 1 and the components of the plasma C VD device 100 are controlled.
  • the processing container 1 is formed of a substantially cylindrical container that is grounded.
  • the processing container 1 may be formed of a rectangular tube-shaped container.
  • the processing container 1 has a bottom wall l a and a side wall l b made of a material such as aluminum.
  • a mounting table 2 for horizontally supporting a semiconductor wafer (hereinafter simply referred to as “wafer”) W such as a silicon substrate which is an object to be processed.
  • the mounting table 2 is made of a material having high thermal conductivity, such as ceramics such as A 1 N.
  • the mounting table 2 is supported by a cylindrical support member 3 extending upward from the center of the bottom of the exhaust chamber 11.
  • the support member 3 is made of ceramics such as A 1 N, for example.
  • the mounting table 2 is provided with a cover ring 4 for covering the outer edge portion thereof and guiding the wafer W.
  • the covering 4 is an annular member made of a material such as quartz, A 1 N, A 1 2 0 3 , Si N or the like.
  • a resistance heating type heater 5 as a temperature adjusting mechanism is embedded in the mounting table 2.
  • the mounting table 2 is heated by being supplied with power from the heat source 5 a, and the wafer W as the object to be processed is uniformly heated by the heat.
  • the mounting table 2 is provided with a thermocouple (TC) 6.
  • TC thermocouple
  • the heating temperature of the wafer W can be controlled in the range from room temperature to 900 ° C., for example.
  • the mounting table 2 has wafer support pins (not shown) for supporting the wafer W and moving it up and down.
  • Each wafer support pin is provided so as to protrude and retract with respect to the surface of the mounting table 2.
  • a circular hole 10 is formed in the approximate center of the bottom wall 1a of the processing vessel 1. ing.
  • the bottom wall la is provided with an exhaust chamber 11 that communicates with the inside of the processing container 1 and protrudes downward.
  • An exhaust pipe 1 2 is connected to the exhaust chamber 11, and is connected to the exhaust device 24 via the exhaust pipe 12.
  • An opening is formed in the upper part of the processing container 1, and a plate 13 having a function as a lid (lid) for opening and closing the processing container 1 is disposed in the opening.
  • the inner peripheral portion of the plate 13 protrudes toward the inside (the space in the processing container 1) to form an annular support portion 13a.
  • the plate 13 is provided with an annular gas introduction hole 14. Further, a gas introduction hole 15 is provided in the side wall 1 b of the processing container 1. That is, the gas introduction holes 14 and 15 are provided in two upper and lower stages.
  • the gas introduction holes 14 and 15 are connected to a gas supply device 18 for supplying a film forming source gas and a plasma excitation gas.
  • the gas introduction holes 14 and 15 may be provided in a nozzle shape or a shower head shape. Further, the gas introduction hole 14 and the gas introduction hole 15 may be provided in a single shutter head.
  • a loading / unloading port 16 for loading / unloading the wafer W between the plasma CVD apparatus 100 and a transfer chamber (not shown) adjacent thereto, A gate valve 1 7 for opening and closing the loading / unloading port 16 is provided.
  • the gas supply device 18 includes a gas supply source (for example, a nitrogen (N) -containing gas supply source 19a, a silicon (Si) -containing gas supply source 19b, an inert gas supply source 19c, and a cleaning gas.
  • Source 19 d for example, gas lines 2 0 a, 2 0 b, 2 0 c, 2 0 d) and flow control devices (for example, mass port controllers 2 1 a, 2 1 b, 2 1 c, 2 0 d) and And valves (for example, on-off valves 2 2 a, 2 2 b, 2 2 c, 2 2 d).
  • the nitrogen-containing gas supply source 19 a is connected to the upper gas introduction hole 14.
  • the silicon-containing compound gas supply source 19 b, the inert gas supply source 19 c, and the cleaning gas supply source 19 d are connected to the lower gas introduction hole 15.
  • the gas supply device 18 may include a purge gas supply source used when replacing the atmosphere in the processing container 1 as a gas supply source (not shown) other than the above, for example.
  • nitrogen gas (N 2 ) is used as a nitrogen-containing gas that is a film forming source gas.
  • silicon-containing compound gases which are film-forming source gases, include, for example, silane (S i H 4 ), disilane (S i 2 H 6 ), trisilane (S i 3 H 8 ), TSA (trisilylamine).
  • Etc. can be used.
  • disilane (S i 2 H 6 ) is particularly preferred. That is, for the purpose of controlling the size of the band gap of the silicon nitride film, a combination using nitrogen gas and disilane as the film forming source gas is preferable.
  • ⁇ 2 gas or rare gas can be used as an inert gas?
  • the rare gas is useful for generating stable plasma as a plasma excitation gas.
  • Ar gas, Kr gas, Xe gas, and He gas can be used.
  • the cleaning gas include C 1 F 3 , NF 3 , HC 1, F, and the like.
  • the nitrogen-containing gas is supplied from the nitrogen-containing gas supply source 1 9 a of the gas supply device 1 8 to the gas introduction part via the gas line 2 0 a and the gas introduction hole 1 4 is introduced into the processing container 1.
  • the silicon-containing compound gas, the inert gas, and the cleaning gas are supplied from the silicon-containing compound gas supply source 19 b, the inert gas supply source 19 c, and the cleaning gas supply source 19 d, respectively. It reaches the gas introduction part via b to 20 d and is introduced into the processing container 1 from the gas introduction hole 15.
  • Each gas line 20 a to 20 d connected to each gas supply source is provided with mass flow controllers 21 a to 21 d and opening / closing valves 2 2 a to 22 d before and behind the mass flow controllers 21 a to 21 d.
  • the supplied gas can be switched and the flow rate can be controlled.
  • the rare gas for plasma excitation such as Ar is an arbitrary gas, and it is not always necessary to supply it simultaneously with the film forming source gas.
  • Exhaust device 2 4 is a vacuum pump such as a monomolecular pump (not shown)
  • the exhaust device 24 is connected to the exhaust chamber 11 of the processing container 1 via the exhaust pipe 12 o By operating this vacuum pump, the gas in the processing container 1 is Exhaust chamber 1 1 space
  • Microphone mouth wave introduction mechanism 27 includes a transmission plate 28, a planar antenna 31, a slow wave material 33, a cover member 34, a waveguide 37, and a microwave generator 39 as main components. ing.
  • Transmission plate 28 that transmits microwaves is disposed on a support portion 13 a that protrudes to the inner peripheral side of the plate 13.
  • Transmission plate 2 8 Dielectric is composed of, for example quartz or A 1 2 0 3, AIN, etc. of the ceramic.
  • a space between the transmission plate 2 8 and the support portion 13 a is hermetically sealed through a seal member 29. Therefore, the processing container 1 is kept airtight.
  • the planar antenna 31 is provided above the transmission plate 28 so as to face the mounting table 2.
  • the planar antenna 3 1 has a disk shape.
  • the shape of the planar antenna 3 1 is not limited to a disk shape, and may be a square plate shape, for example.
  • the planar antenna 31 is locked to the upper end of the plate 13.
  • the planar antenna 31 is made of, for example, a copper plate, a nickel plate, a SUS plate or an aluminum plate whose surface is plated with gold or silver.
  • the planar antenna 31 has a number of slot-shaped microwave radiation holes 32 that radiate microwaves.
  • the microwave radiation hole 3 2 is formed to penetrate the planar antenna 3 1 in a predetermined pattern.
  • each microphone mouth wave radiation hole 3 2 has an elongated rectangular shape (slot shape), and two adjacent microwave radiation holes form a pair.
  • adjacent microwave radiation holes 32 are arranged in a “T” shape.
  • the microwave radiation holes 32 arranged in a predetermined shape (for example, T-shape) in this way are further arranged concentrically as a whole.
  • Microwave radiation holes 3 2 The length and arrangement interval of microwave holes (microwave wavelength ( PT / JP2009 / 057006 ⁇ g)
  • the interval between the microwave radiation holes 3 2 is arranged to be from A g Z 4; lg.
  • the interval between adjacent microwave radiation holes 3 2 formed concentrically is indicated by ⁇ !
  • the shape of the microwave radiation hole 3 2 may be another shape such as a circular shape or an arc shape.
  • the arrangement form of the microwave radiation holes 32 is not particularly limited, and the microwave radiation holes 32 can be arranged concentrically, for example, spirally, radially, or the like.
  • a slow wave material 33 having a dielectric constant larger than that of vacuum is provided on the upper surface of the planar antenna 3 1.
  • This slow wave material 33 has a function of adjusting the plasma by shortening the wavelength of the microwave because the wavelength of the microwave becomes longer in vacuum.
  • planar antenna 3 1 and the transmission plate 28 and the slow wave material 3 3 and the planar antenna 3 1 may be contacted or separated from each other, but are preferably in contact with each other.
  • a cover member 3 4 is provided on the upper portion of the processing container 1 so as to cover the planar antenna 3 1 and the slow wave material 3 3.
  • the cover member 34 is formed of a metal material such as aluminum or stainless steel. The upper end of the plate 13 and the cover member 3 4 are sealed by a seal member 3 5. Inside the cover member 3 4, a cooling water flow path 3 4 a is formed. By passing the cooling water through the cooling water flow path 3 4 a, the cover member 3 4, the slow wave material 3 3, the planar antenna 3 1 and the transmission plate 2 8 are cooled, and these members are damaged or deformed. Can be prevented.
  • the cover member 34 is grounded. (0 0 4 1)
  • An opening 3 6 is formed at the center of the upper wall (ceiling) of the cover member 3 4, and a waveguide 3 7 is connected to the opening 3 6.
  • the other end of the waveguide 37 is connected to a microwave generator 39 that generates a microwave via a matching circuit 38.
  • the waveguide 37 is formed of a coaxial waveguide 37a having a circular cross section extending upward from the opening 36 of the cover member 34, and an upper end of the coaxial waveguide 37a. And a rectangular waveguide 3 7 b extending horizontally.
  • An inner conductor 41 extends in the center of the coaxial waveguide 37a.
  • the inner conductor 41 is connected and fixed to the center of the planar antenna 31 at the lower end thereof.
  • the coaxial waveguide 3 7 a is formed in communication with a radial flat waveguide formed by the cover member 3 4 and the planar antenna 3 1. With such a structure, microwaves are efficiently and uniformly propagated radially and uniformly to the planar antenna 31 via the inner conductor 4 1 of the coaxial waveguide 37a.
  • the microwave generated by the microwave generator 39 is propagated to the planar antenna 3 1 via the waveguide 37, and the transmission plate 28 is It is introduced into the processing container 1 via
  • the microwave frequency for example, 2.45 GHz is preferably used, and 8.35 GHz, 1.9.8 GHz, or the like can also be used.
  • the control unit 50 has a computer.
  • the process controller 51 having a CPU and a user interface connected to the process controller 51 are used.
  • a face 52 and a storage unit 53 are provided.
  • the process controller 51 is a component related to process conditions such as temperature, pressure, gas flow rate, and microwave output (for example, a heat source 5a, a gas supply apparatus 1). 8, exhaust system 24, microwave generator 39, etc.).
  • the user interface 5 2 is a keypad for the process manager to input commands to manage the plasma CVD apparatus 10 0 0, etc. Etc.
  • the storage unit 53 also has a recipe in which a control program (software) and processing condition data for realizing various processes executed by the plasma CVD apparatus 100 are controlled by the process controller 51. Is saved.
  • the process controller 51 can call an arbitrary recipe from the storage unit 53 and execute it in the process controller 51 according to an instruction from the user interface 51. Under the control, a desired process is performed in the processing chamber 1 of the plasma CVD apparatus 100.
  • the recipes such as the control program and processing condition data are stored in a computer-readable storage medium such as a CD-ROM, a hard disk, a flexible disk, a flash memory, a DVD, or a Blu-ray disc. Or from other devices, for example, via a dedicated line. JP2009 / 057006 can also be used on-line.
  • the gate valve 17 is opened, and the wafer W is loaded into the processing container 1 from the loading / unloading port 16 and mounted on the mounting table 2.
  • nitrogen is supplied from the nitrogen-containing gas supply source 19a, the silicon-containing compound gas supply source 19b and the inert gas supply source 19c of the gas supply device 18.
  • Gas, silicon-containing compound gas, and if necessary, rare gas are introduced into the processing vessel 1 through the gas introduction holes 14 and 15 at predetermined flow rates, respectively. In this way, the inside of the processing container 1 is adjusted to a predetermined pressure.
  • a microwave having a predetermined frequency, for example, 2.45 GHz, generated by the microwave generator 39 is guided to the waveguide 37 via the matching circuit 38.
  • the microphone mouth wave guided to the waveguide 3 7 sequentially passes through the rectangular waveguide 3 7 b and the coaxial waveguide 3 7 a, is propagated radially to the flat waveguide, and the planar antenna plate 3 1 To be supplied. That is, the microwave propagates in the coaxial waveguide 37a toward the planar antenna plate 31, and further radiates in the flat waveguide formed by the cover member 34 and the planar antenna 31.
  • the microwave propagated to the wafer is radiated from the slot-like microwave radiation hole 3 2 of the planar antenna plate 3 1 to the space above the wafer W in the processing chamber 1 through the transmission plate 2 8.
  • the microwave output at this time is preferably in the range of 0.25 to 2.56 W / cm 2 as the power density per area of the transmission plate 28.
  • the microwave output can be selected, for example, from the range of 500 to 500 W so that the power density is within the above range according to the purpose. (0 0 5 0)
  • An electromagnetic field is formed in the processing container 1 by the microwave radiated from the planar antenna 31 to the processing container 1 through the transmission plate 28, and nitrogen-containing gas and silicon-containing compound gas are turned into plasma. Then, the dissociation of the source gas efficiently proceeds in the plasma, and active species such as ion radicals, such as S i P H Q , S i H NH i N (where p and ci mean any number) The same shall apply hereinafter.) A thin film of silicon nitride Si N is deposited by such a reaction.
  • the pressure condition of the plasma C VD treatment when forming the silicon nitride film is made constant, and the flow rate ratio between the silicon-containing compound gas and the nitrogen gas (silicon-containing By changing the compound gas / nitrogen gas flow rate ratio within the range of 0.005 to 0.2, the band gap of the silicon nitride film to be formed is 2.5 eV or more and 7 eV or less.
  • the desired size can be controlled within the range. For example, when the processing pressure is in the range of 0.1 Pa to 4 Pa, the formation reaction of the silicon nitride film is restricted by the supply of silicon-containing compound molecules that are precursors.
  • the silicon nitride film becomes relatively nitrogen-rich and the energy gap can be increased.
  • the silicon nitride film becomes relatively silicon-rich and the energy band gap Can be reduced.
  • the processing pressure is in the range of 40 Pa or more and 1 3 3 3 Pa or less
  • the formation of the silicon nitride film has a strong tendency of reaction regulation. for that reason,
  • the silicon nitride film is not likely to be silicon-rich, but rather relative. It becomes a nitrogen-rich and can increase the energy span gap.
  • the ratio of the silicon-containing compound gas to the nitrogen gas is reduced, the silicon nitride film becomes a relatively silicon rich, and the energy band gap can be reduced.
  • the size of the band gap by changing the nitrogen content and silicon content in the silicon nitride film with high responsiveness according to the Si 2 H 6 / N 2 flow rate ratio in the film forming source gas.
  • This is a feature of the plasma C VD device 100.
  • the composition of the silicon nitride film is stoichiometric even if the Si 2 H 6 / N 2 flow ratio of the film forming source gas is changed.
  • the ratio (Si 3 N 4 ) did not vary greatly, and it was virtually impossible to intentionally form a nitrogen-rich or silicon-rich film.
  • silicon nitride can be formed according to the Si 2 H 6 / N 2 flow rate ratio in the film forming raw material gas. By changing the Si / N ratio in the film with good controllability, it is possible to easily form a silicon nitride film having a target band gap.
  • FIG. 4A and 4B are process diagrams showing a silicon nitride film manufacturing process performed in the plasma C VD apparatus 100. As shown in Fig. 4A, on an arbitrary underlayer (eg, silicon dioxide film) 60, Si 2 H 6 PT / JP2009 / 057006
  • an arbitrary underlayer eg, silicon dioxide film
  • Plasma C VD treatment is performed at a processing pressure using ZN 2 plasma.
  • a film-forming gas containing a silicon-containing compound gas and nitrogen gas is used, and the process pressure is in the range of 0. l Pa to 4 Pa, or 40 Pa to 1 3 3 3 P.
  • the flow rate ratio of silicon-containing compound gas / nitrogen gas is controlled within a range of not less than 0.005 and not more than 0.2 by making the value constant within a range of a or less.
  • a silicon nitride film 70 having a band gap in the range of 2.5 eV to 7 eV can be formed.
  • N 2 gas is used as the nitrogen-containing gas
  • Si 2 H 6 gas is used as the silicon-containing compound gas.
  • Plasma C VD is performed in the plasma C VD apparatus 100, and a single silicon nitride film is formed. The relationship between the band gap of the silicon nitride film and the processing pressure when formed is shown.
  • the plasma CVD conditions are as follows.
  • Processing temperature (mounting table): 5 0 0 ° C
  • Microwave power 2 k W (power density 1.0 2 3 W / cm 2 ; per transmission plate area)
  • the band gap of the silicon nitride film was measured using a thin film characteristic measuring apparatus n & k • Analyzer (trade name; manufactured by n & k Technology Co., Ltd.).
  • N 2 gas as nitrogen-containing gas, Si 2 H 6 gas as silicon-containing compound gas, and Ar gas as inert gas are used.
  • Set the processing pressure to 2.7 Pa (2 0 mT orr) or 6 6.7 Pa (5 0 0 mT orr) and set the Si 2 H 6 / N 2 flow ratio from 0.0 1
  • the band gap of the formed silicon nitride film changed within the range of about 4, 8 eV to 6. OeV.
  • the ratio of Si ZN contained in the silicon nitride film is controlled to easily perform nitriding having a desired band gap.
  • a silicon film can be formed.
  • the band gap is increased by changing the pressure. It can be seen that the thickness can be adjusted.
  • the silicon nitride film was formed by LPC VD with the process pressure changed in the same way, but the band gap remained in the range of 4.9 eV to 5 eV. It was difficult (results omitted).
  • the main factor that determines the size of the band gap to be formed is the silicon-containing compound gas nitrogen gas flow rate ratio. . Therefore, using the plasma C VD apparatus 1 0 0, the other conditions are -constant and only the silicon-containing compound gas / nitrogen gas flow ratio is changed. As a result, it was confirmed that a silicon nitride film having a relatively large bandgap and a small silicon nitride film can be easily formed by controlling the ratio of Si ZN contained in the film.
  • the processing pressure is in the range of 0. l Pa to 4 Pa, or 40 P. It is preferable to set the flow rate within a range from a to 1 3 3 3 Pa, and the silicon-containing compound gas / nitrogen gas flow ratio is preferably selected from the range from 0.0 0 5 to 0.2. It is more preferable to select from the range of 5 to 0.1 or less.
  • the flow rate of Ar gas is 0 (not supplied) to: LOOO mLZm in (sccm), preferably within the range of 50 to 800 mLZm in (sccm), and the flow rate of N 2 gas is
  • the flow rate of Si 2 H 6 gas is in the range of 10 0 to 80 0 mL / in (sccm), preferably in the range of 100 to 400 mL / min (sccm):!
  • the flow rate ratio can be set within the range of ⁇ 400 mL / min (sccm), preferably within the range of 3 to 30 mL min (sccm).
  • the processing temperature of the plasma C VD processing is set so that the temperature of the mounting table 2 is not less than 300 ° C., preferably not less than 4 00 ° C. and not more than 60 ° C.
  • the microwave power density in the plasma CVD process is preferably in the range of 0.256 6 WZ cm 2 or more and 2.045 5 W / cm 2 or less per area of the transmission plate.
  • silicon-containing film is used.
  • a deposition gas containing a compound gas and a nitrogen gas By using a deposition gas containing a compound gas and a nitrogen gas, a silicon-containing compound gas, selecting the nitrogen gas flow rate ratio and the processing pressure, and performing plasma C VD, the ratio of Si ZN contained in the film
  • the ratio of Si ZN contained in the film By controlling the above, it is possible to easily manufacture silicon nitride films of various sizes on the wafer W.
  • the conditions of the plasma CVD process when forming the silicon nitride film are selected.
  • the band gap of the silicon nitride film formed by controlling the ratio of Si / N contained in the film can be controlled to a desired size. Therefore, for example, a silicon nitride film laminate composed of a plurality of silicon nitride films having different band gap sizes between adjacent silicon nitride films can be easily manufactured.
  • FIG. 6A to FIG. 6F are process diagrams showing a manufacturing process of the silicon nitride film laminate performed in the plasma C VD apparatus 100.
  • a first flow rate ratio (S i 2 H 6) using Si 2 H 6 / N 2 plasma on an arbitrary underlayer (eg, silicon dioxide film) 60.
  • a plasma C VD process is performed at a / N 2 flow rate ratio, and as shown in FIG. 6B, a first silicon nitride film 70 having a first band gap is formed.
  • a second flow rate ratio (S i 2 H 6 / N 2) is formed on the first silicon nitride film 70 using Si 2 H 6 / N 2 plasma.
  • a plasma CVD process is performed at a flow rate ratio to form a second silicon nitride film 71 having a second band gap, as shown in FIG. 6D.
  • a silicon nitride film laminate 80 composed of a silicon nitride film can be formed.
  • a third flow ratio (S i 2) is used by using Si 2 H 6 / N 2 plasma on the second silicon nitride film 7 1. It is also possible to perform plasma CVD treatment at a H 6 / N 2 flow ratio) to form a third silicon nitride film 72 having a third band gap as shown in FIG. 6F.
  • the silicon nitride film laminate 80 having a desired layer structure can be formed by repeating the plasma C VD treatment as many times as necessary.
  • a film-forming gas containing a silicon-containing compound gas and a nitrogen gas is used, and the silicon-containing compound gas / nitrogen gas flow rate ratio is not less than 0.05 and not more than 0.2.
  • the silicon-containing compound gas / nitrogen gas flow rate ratio is not less than 0.05 and not more than 0.2.
  • Select from the range, and perform plasma C VD by setting the processing pressure constant within the range of 0. l Pa to 4 Pa, or within the range of 40 Pa to 1 3 3 3 Pa.
  • the band gap of the silicon nitride film can be changed within the range of 2.5 eV to 7 eV by controlling the ratio of Si / N contained in the film. That is, the processing pressure is kept constant within the range of 0. 1 Pa to 4 Pa, or within the range of 40 Pa to 1 3 3 3 Pa.
  • the first silicon nitride film 70 by controlling the ratio of Si ZN contained in the film by changing the ratio and the third flow rate ratio within the range of 0.005 to 0.2.
  • the band gap sizes of the second silicon nitride film 71 and the third silicon nitride film 72 can be controlled within the range of 2.5 eV to 7 eV.
  • the processing pressure is set constant within the range of 0.1 Pa or more and 4 Pa or less, and the silicon-containing compound gas / nitrogen gas flow rate ratio is set within the range of 0.005 to 0.2 and below.
  • 1st flow ratio 2nd flow ratio ⁇ 3rd T / JP2009 / 057006 If the flow ratio is selected, the size of the band gap is as follows: first silicon nitride film 70> second silicon nitride film 7 1> third silicon nitride film 7 2
  • a silicon nitride film laminate 80 having an energy band structure can be formed.
  • the processing pressure is set constant within the range of 40 Pa to 1 3 3 3 Pa, and the silicon-containing compound gas nitrogen gas flow ratio is in the range of 0.0 0 5 to 0.2.
  • the band gap is larger than the first silicon nitride film 70 by the second silicon nitride film.
  • a silicon nitride film laminate 80 having an energy band structure, which is a third silicon nitride film 72, can be formed.
  • the processing pressure is set in the range of 0.1 to 4 Pa.
  • Set the silicon-containing compound gas Z nitrogen gas flow rate ratio within the range of 0.04 or more and 0.2 or less, or set the processing pressure to 40 Pa or more and 1 3 3 3 Pa or less. It is preferable that the silicon-containing compound gas / nitrogen gas flow rate ratio is set within the range, and is selected from the range of 0.005 or more and 0.01 or less.
  • the flow rate of Ar gas is in the range of 0 to 100 mL / min (sccm), preferably in the range of 5 0 to 8 0 01111 ⁇ / 111 1 11 (sccm), N 2 gas
  • the flow rate of the gas is in the range of 1 0 0 to 8 0 0 111 / / 111 1 11 (sccm), preferably in the range of 1 0 0 to 4 0 0 mL / min (sccm), S i 2 H 6
  • the gas flow rate is in the range of 1 to 40 mL / min (sccm), preferably in the range of 2 to 20 mLZm in (sccm).
  • T / JP2009 / 057006 can be set to achieve the above flow ratio.
  • the processing pressure is set in the range of 0.1 l Pa to 4 Pa
  • Silicon-containing compound gas Z Nitrogen gas flow rate ratio is selected from the range of 0.05 or more and 0.2 or less, or the processing pressure is constant within the range of 40 Pa or more and 1 3 3 3 Pa or less
  • the Ar gas flow rate is 0 L 0 00 m L / min, sccm), preferably within 50 80 mL / min (sccm), N 2 gas flow rate within 10 00 800 mL / min (sc C m), preferably 1 Within the range of 0 0 4 0 0 m L / min (secm), the flow rate of Si 2 H 6 gas is within the range of l 4 0 mL /
  • the processing temperature of the plasma C V D processing is set within the range of 300 ° C. or higher, preferably ⁇ 400 ° C. or higher and 60 ° C. or lower, of the temperature of the mounting table 2.
  • the Pawa one density of the microphone port waves in even plasma CVD process in either case, the permeation area per 0. 2 5 6 W / cm 2 or more on the plate 2. the range of 0 4 5 W / cm 2 or less It is preferable to do.
  • a silicon-containing compound gas is used, using a film-forming gas containing a silicon-containing compound gas and a nitrogen gas.
  • PT / JP2009 / 057006 By selecting the nitrogen gas flow ratio and processing pressure and performing plasma CVD, silicon nitride films with different band gaps are alternately deposited on the wafer W to form a silicon nitride film stack. Can be formed.
  • the band gap is controlled by controlling the ratio of Si / N contained in the silicon nitride film according to the flow rate ratio of silicon-containing compound gas / nitrogen gas with a constant processing pressure. Therefore, when forming a stack of silicon nitride films having different band gaps, it is possible to continuously form films while maintaining a vacuum state in the same processing vessel, and process efficiency It is extremely advantageous in improving the quality.
  • the bandgap of the silicon nitride film can be easily adjusted by controlling the Si / N ratio contained in the film only by adjusting the flow rate ratio of the silicon-containing compound gas / nitrogen gas while keeping the processing pressure constant. Therefore, it is possible to easily manufacture silicon nitride film laminates having various band gap structures. Therefore, by applying the method of the present invention to the formation of a silicon nitride film stack as a charge storage region of a MOS type semiconductor memory device, excellent data retention characteristics, high-speed data rewriting performance, and low consumption It is possible to manufacture MOS-type semiconductor memory devices that have both power performance and high reliability.
  • FIG. 7 is a cross-sectional view schematically showing a schematic configuration of a plasma CVD apparatus 200 that can be used in the method of manufacturing a silicon nitride film according to the present embodiment.
  • a plasma CVD apparatus 200 that can be used in the method of manufacturing a silicon nitride film according to the present embodiment.
  • an electrode 7 is embedded on the surface side of the mounting table 2.
  • the electrode 7 is disposed between the heater 5 and the surface of the mounting table 2.
  • a high frequency power supply 9 for bias is connected to the electrode 7 via a matching box (M.B.) 8 by a feeder line 7a.
  • a high-frequency bias voltage (R F bias) can be applied to the wafer W, which is the substrate.
  • the material of the electrode 7 is preferably a material having a thermal expansion coefficient equivalent to that of ceramics such as A 1 N which is the material of the mounting table 2, and for example, a conductive material such as molybdenum or tungsten is preferably used.
  • the electrode 7 is formed in, for example, a mesh shape, a lattice shape, a spiral shape, or the like.
  • the size of the electrode 7 is preferably at least equal to or larger than the object to be processed.
  • the silicon nitride film deposition process by the plasma CVD method using the plasma CVD apparatus 200 will be described.
  • the gate valve 17 is opened, and the wafer W is loaded into the processing container 1 from the loading / unloading port 16 and mounted on the mounting table 2.
  • nitrogen is supplied from the nitrogen-containing gas supply source 19a, the silicon-containing compound gas supply source 19b and the inert gas supply source 19c of the gas supply device 18 Contained gas, silicon-containing compound gas and inert gas (eg Ar gas) JP2009 / 057006
  • a microwave having a predetermined frequency, for example, 2.45 GHz, generated by the microwave generator 39 is guided to the waveguide 37 via the matching circuit 38.
  • the microwave guided to the waveguide 3 7 sequentially passes through the rectangular waveguide 3 7 b and the coaxial waveguide 3 7 a and is supplied to the planar antenna plate 3 1 through the inner conductor 4 1. That is, the microwave propagates in the coaxial waveguide 3 7 a toward the planar antenna plate 3 1.
  • the microphone mouth wave is radiated from the slot-like microwave radiation hole 32 of the planar antenna plate 31 to the space above the wafer W in the processing chamber 1 through the transmission plate 28.
  • the microwave output at this time is preferably in the range of 0.25 to 2.56 W / cm 2 as the output density per area of the transmission plate 28 in the region where the microwave is transmitted.
  • the microwave output can be selected, for example, from the range of 500 to 500 W so that the output density is within the above range according to the purpose.
  • An electromagnetic field is formed in the processing container 1 by the microwave radiated from the planar antenna 3 1 to the processing container 1 through the transmission plate 2 8, and Ar gas, nitrogen-containing gas, and silicon-containing compound gas are turned into plasma, respectively. .
  • the dissociation of the source gas in the plasma processing proceeds efficiently, active species such as ions and radicals, e.g. S i P H There S i H Q, NH, by reactions such as N,, a thin film of silicon nitride S i N Is deposited.
  • a high frequency power (RF) of a predetermined frequency and magnitude is applied to the electrode 7 of the mounting table 2 from the high frequency power source 9. 057006 Bias) to wafer W.
  • RF radio frequency
  • the plasma electron temperature can be kept low, there is no damage to the film, and the molecules of the film forming gas are easily dissociated by the high-density plasma, thus promoting the reaction.
  • the application of RF bias in the appropriate range acts to attract ions in the plasma to the wafer W, so the Si / N ratio of the silicon nitride film to be formed can be controlled, and the band gap can be reduced. Acts to change.
  • the frequency of the RF bias supplied from the high-frequency power supply 9 is preferably in the range of, for example, 4 00 kHz to 6 O MHz, and 4 500 kHz to 2 O MHz. The following range is more preferable.
  • the RF bias is preferably supplied within the range of, for example, 0.0 1 W cm 2 or more and 0.64 WZ cm 2 or less as the output density per wafer W area. It is more preferable to supply within the range of 0.0 3 2 W / cm 2 or more and 0.1 6 WZ cm 2 or less.
  • the RF bias output is preferably in the range of 1 W or more and 20 0 W or less, more preferably in the range of 1 W or more and 50 0 W or less so that the RF bias is set to the above output density. Can be supplied.
  • the above conditions are stored as recipes in the storage unit 53 of the control unit 50.
  • the process controller 51 reads the recipe, and each component of the plasma C VD device 200, for example, the gas supply device 18, the exhaust device 24, the microwave generator 39, the heater power source 5 a, high By sending control signals to the frequency power supply 9 etc., plasma C VD processing under the desired conditions is realized.
  • high-frequency power is applied to the electrode 7 of the mounting table 2 from the high-frequency power source 9 to 0.0 1 W / cm 2 or more 6 4 WZ cm 2 or less, preferably 0. 0 3 2 ⁇ / cm 2 or more 0.1. 6 W / cm 2 or less to supply RF bias to wafer W by supplying it within the range of power density.
  • the band gap can be controlled by controlling the Si / N ratio of the silicon nitride film formed.
  • FIG. 8A and FIG. 8B are process diagrams showing the manufacturing process of the silicon nitride film performed in the plasma C VD apparatus 200.
  • a plasma C VD process is performed using N 2 ZS i 2 H 6 plasma on an arbitrary underlayer (eg, S i 0 2 film) 6 0).
  • high-frequency power is supplied from the high-frequency power source 9 to the electrode 7 of the mounting table 2 at a power density within a range of 0.0 l W / cm 2 or more and 0.64 WZ cm 2.
  • RF bias is applied to wafer W.
  • FIG. 8B a silicon nitride film 70 with a controlled Si / N ratio can be formed, and the band gap of the silicon nitride film 70 can be changed.
  • Plasma C VD was performed under the following conditions, and an experiment was conducted to evaluate the relationship between the RF bias output supplied during film formation and the band gap size of the silicon nitride film to be formed.
  • Processing temperature (mounting table): 4 0 0 ° C
  • Microwave power 2 kW (Power density 1.5 3 W / cm 2 ; Permeation area) 57006 Processing pressure: 2.7 Pa, 2 6. 6 Pa or 40 Pa
  • R F Bias RF power 0 W (not supplied), 5 W, 10 W,
  • the Si ZN ratio decreased as the RF bias RF power increased, and the band gap tended to increase as a nitrogen-rich silicon nitride film.
  • the processing pressure is 40 Pa
  • the band gap increases as the RF bias RF power to the wafer W is increased within the RF bias RF power density range of 0.0 3 2 WZ cm 2 or higher.
  • the treatment pressure is set to 0.1 l Pa or more and 1 3 3 3 Pa or less, preferably 1 Pa.
  • the flow rate ratio between silicon-containing compound gas and N 2 gas (for example, Si 2 H 6 flow rate / N 2 flow rate) is set to 0.
  • High frequency power density for RF bias selected from the range of 0 0 5 or more and 0.2 or less, and preferably supplied within the range of 0. Ol W / cm 2 or more and 0.64 WZ cm 2 or less. It was shown that it is more preferable to supply within the range of 0.0 3 2 W / cm 2 or more and 0.1 6 W / cm 2 or less.
  • Plasma CVD conditions Is as follows.
  • Processing temperature (mounting table): 4 0 0 ° C
  • Microwave power 2 kW (power density 1.5 3 W / cm 2 ; per plate area)
  • Ar gas flow rate l O O mL / m i n (s c c m), 60 m L / m i n (s c c m) or l l O O mL / m i n (s c c m)
  • R High frequency power for bias 0 W (not supplied), 5 W, 10 W, 50 W
  • the flow rate of Ar gas when applying the RF bias is 0 (not supplied) l OOO mL / min (sccm) Preferably within the range of 100 to 60 O mL / min (sccm). I was able to confirm.
  • the other configurations and effects of the third embodiment are the same as those of the first embodiment.
  • the wafer W as shown in the third embodiment is used. It is also possible to manufacture silicon nitride film stacks by changing the magnitude of the RF bias to
  • FIGS. 11A and 11B are views for explaining a method of manufacturing a silicon nitride film according to the fourth embodiment of the present invention.
  • the silicon nitride film formed in the plasma C VD apparatus 100 is shown in FIGS. It is a process diagram showing a manufacturing process.
  • ammonia gas NH 3 gas
  • plasma C VD treatment is performed on an arbitrary underlayer (eg, silicon dioxide film) 6 OA at a treatment pressure using Si 2 H 6 ZNH 3 plasma.
  • a deposition gas containing silicon-containing compound gas and ammonia gas is used, and the flow rate ratio of silicon-containing compound gas / ammonia gas is set within the range of 0.015 to 0.2, and 0.1 Plasma C VD treatment is performed by selecting a treatment pressure from the range of Pa to 1 3 3 3 Pa.
  • a silicon nitride film 7OA having a large gap in the range of 2.5 eV to 7 eV can be formed.
  • the band gap of PT / JP2009 / 057006 tends to increase. Therefore, by selecting the processing pressure within the range of 0.1 l Pa to 1 3 3 3 Pa above, the band gap size of the silicon nitride film 7 OA is set to 2.5 eV to 7 Can be controlled within the eV range.
  • Fig. 12 shows the nitriding of a single film using NH 3 gas as the nitrogen-containing gas and Si 2 H 6 gas as the silicon-containing compound gas, and performing plasma C VD in the plasma C VD device 100.
  • the relationship between the band gap of the silicon nitride film and the processing pressure when the silicon film is formed is shown.
  • the plasma C VD conditions are as follows.
  • Processing temperature (mounting table): 5 0 0 ° C
  • Microwave power 2 kW (Power density 1.0 2 3 W / cm 2 ; per transmission plate area)
  • Processing pressure 13.3 Pa (100 mTorr), 66.7 Pa (500 mTorr),
  • the band gap of the silicon nitride film is measured using a thin film property measuring device n & k • A na 1 yzer (trade name; manufactured by n & k Technology). Measured.
  • the band gap of the silicon nitride film to be formed is about 5.1 eV to 5.8 eV. Changed within range.
  • a silicon nitride film having a desired band gap can be easily formed by changing only the processing pressure while keeping the Si 2 H 6 flow rate constant. It is also preferable to mainly control the processing pressure and, if necessary, control the Si 2 H 6 flow rate as a slave.
  • the flow rate of the source gas for forming the band gap in the above range is as follows.
  • the Si 2 H 6 flow rate is preferably in the range of 3 mL / min (secm) to 40 mL / min (sccm), and is 3 mL / min (sccm) 3 ⁇ 4 ⁇ 2 O mL / min (sccm) or less.
  • the lower range is more preferable.
  • NH 3 flow rate is preferably in the range of 50 mL / min (sccm) or more to lOO mL / min (sccm) or less, more than 50 mL / min (sccm) to 50 mL / min (sccm)
  • the following range is more preferable.
  • the flow rate ratio between the Si 2 H 6 gas and the NH 3 gas is preferably in the range of 0.0 1 5 or more and 0.2 or less, and 0.0 1 5 Within the range of ⁇ 0.1 or less is more preferable.
  • a silicon nitride film was formed by LPCVD with the process pressure varied in the same way, but the node gap remained within the range of 4.9 eV to 5 eV, and the bandgap was controlled by LPCVD. It was difficult (results omitted).
  • the plasma CV using the plasma C VD device 1 0 0 In the D process it was found that the main factor that determines the size of the band gap to be deposited is the processing pressure. Therefore, by using the plasma C VD apparatus 100, other conditions are kept constant, and the size of the band gap is controlled by changing only the processing pressure, so that a silicon nitride film having a relatively large band gap can be obtained. It was confirmed that a small silicon nitride film can be easily formed.
  • the flow ratio of silicon-containing compound gas (eg, Si 2 H 6 gas) to ammonia gas ( (Silicon-containing compound gas / ammonia gas flow ratio) can be set within the range of 0.0 1 5 or more and 0.2 or less, and the processing pressure can be set to 0.1 Pa or more and 1 3 3 3 Pa or less.
  • the Ar gas flow rate is 0 to: L 0 0 0 m L Zm in
  • the gas flow rate is within the range of 1 0 0-8 0 01111 ⁇ 111 1 n (sccm) , Preferably 100-400 mL / min
  • the flow rate of Si 2 H 6 gas is within the range of 1 to 400 mL / min (sccm), preferably within the range of SSO mLZm in (sccm), respectively, with the above flow ratio.
  • sccm the flow rate of Si 2 H 6 gas is within the range of 1 to 400 mL / min (sccm), preferably within the range of SSO mLZm in (sccm), respectively, with the above flow ratio.
  • the processing temperature of the plasma C VD processing is set such that the temperature of the mounting table 2 is not less than 300 ° C., preferably not less than 400 ° C. and not more than 60 ° C.
  • the microwave power density in plasma C VD treatment is 0.2 5 6 W / cm 2 or more per transmission plate area 2.0 4 5 W / cm 2 It is preferable to be within the following range.
  • a film-forming gas containing a silicon-containing compound gas and an ammonia gas is used.
  • Z Ammonia gas flow ratio is set within the range of 0.0 1 5 or more and 0.2 or less, and plasma C is applied at a processing pressure selected from the range of 0. l Pa or more and 1 3 3 3 Pa or less.
  • the plasma C VD processing conditions particularly the pressure conditions, when forming the silicon nitride film should be selected.
  • the band gap of the formed silicon nitride film can be controlled to a desired size. Therefore, for example, a silicon nitride film laminate composed of a plurality of silicon nitride films having different band gaps between adjacent silicon nitride films can be easily manufactured.
  • FIGS. 13A to 13 F are process diagrams showing a manufacturing process of the silicon nitride film laminate performed in the plasma C VD apparatus 100. First, figure
  • plasma C VD treatment is performed on the first silicon nitride film 7 OA using Si 2 H 6 Z NH 3 plasma at the second treatment pressure.
  • PT / JP2009 / 057006 As shown in FIG. 13D, a second silicon nitride film 71 A having a second band gap is formed. Thereby, a silicon nitride film laminate 8 OA composed of two layers of silicon nitride films can be formed. Further, if necessary, as shown in FIG.
  • the silicon nitride film laminate 8 OA having a desired layer structure can be formed by repeating the plasma CVD process as many times as necessary.
  • a film-forming gas containing a silicon-containing compound gas and an ammonia gas is used, and a silicon-containing compound gas / ammonia gas flow rate ratio is not less than 0.015 and not more than 0.2.
  • a processing pressure selected from the range of 0. l Pa or more and 1 3 3 3 Pa or less.
  • the bandgap of the silicon nitride film can be changed.
  • the processing pressure is in the range of 0.1 l Pa or more and 1 3 3 3 Pa or less, the band gap of the formed silicon nitride film tends to increase as the processing pressure increases.
  • the first processing pressure, the second processing pressure, and the third processing pressure within the range of 0.1 l Pa or more and 1 3 3 3 Pa or less, the first silicon nitride
  • the band gap of the film 70A, the second silicon nitride film 71A and the third silicon nitride film 72A can be controlled within the range of 2.5 eV to 7 eV.
  • the treatment pressure will be 1st treatment pressure> 2nd treatment pressure> 3rd treatment pressure.
  • the band gap has an energy one band structure in which the first silicon nitride film 70 A> the second silicon nitride film 7 1 A> the third silicon nitride film 7 2 A.
  • a silicon nitride film laminate 80 A can be formed.
  • the processing pressure is selected from the range of 0.1 l Pa or more and 1 3 3 3 Pa or less so that the second processing pressure is less than the first processing pressure ⁇ the third processing pressure.
  • the band gap size is the first silicon nitride film 7 OA and the second silicon nitride film 7 1 A and the third silicon nitride film 7 2 A.
  • the silicon nitride film laminate having an energy band structure 8 0 A can be formed.
  • an energy band gap structure in which the first silicon nitride film 70 A the third silicon nitride film 72 A is obtained. It is also possible to make it.
  • a silicon-containing compound gas for example, Si 2 H 6 gas
  • ammonia gas a silicon-containing compound gas
  • the Ar gas flow rate is in the range of 0 to L 0 00 mL / min (sccm), preferably 50 to 80 mL / min.
  • NH 3 gas flow rate is in the range of 100-800 mL / min (sccm), preferably in the range of 100-400 mL / min (sccm), S i 2 H 6 gas flow rate!
  • the flow rate ratio can be set within the range of ⁇ 40 mLZ min (sccm), preferably within the range of 3 to 20 mL / min (sccm).
  • the band gap size is, for example, in the range of more than 5 eV and less than 7 eV.
  • the ratio of silicon-containing compound gas (for example, Si 2 H 6 gas) to ammonia gas (silicon-containing compound gas Z ammonia gas flow rate ratio) is not less than 0.0 15 It is preferable to set the pressure within the range of 0.2 or less, and set the processing pressure to 8.9 Pa or more and 1 3 3 3 Pa or less.
  • the Ar gas flow rate is in the range of 0 to L 0 00 mL / min (sccm), preferably in the range of 50 to 800 mL Zm in (sccm), and the NH 3 gas flow rate is 1.
  • the flow rate of Si 2 H 6 gas is 1 to 40 m
  • the flow rate can be set to the above-mentioned ratio.
  • the processing temperature of the plasma C VD processing is set so that the temperature of the mounting table 2 is not less than 300 ° C, preferably not less than 400 ° C and not more than 60 ° C. .
  • the power density of the microphone mouth wave in the plasma C VD treatment is within the range of 0.2 5 6 W / cm 2 or more and 2.0 45 5 W / cm 2 or less per area of the transmission plate. It is preferable that
  • a film-forming gas containing a silicon-containing compound gas and an ammonia gas is used, and a silicon-containing compound gas Z ammonia gas flow rate ratio is not less than 0.015 and not more than 0.2.
  • a silicon nitride film having a different band gap on the wafer W is set.
  • Alternately deposited silicon nitride A film stack can be formed.
  • the size of the band gap can be easily controlled only by the processing pressure. Therefore, when forming a laminate of silicon nitride films having different band gaps, In this way, continuous film formation is possible while maintaining a vacuum state, which is extremely advantageous for improving process efficiency.
  • the panda gap of the silicon nitride film can be easily adjusted only by adjusting the processing pressure, it is possible to easily manufacture silicon nitride film laminates having various band gap structures. Therefore, by applying the method of the present invention to the formation of a silicon nitride film stack as a charge storage region of a MOS type semiconductor memory device, excellent data retention characteristics, high-speed data rewriting performance, and low power consumption This makes it possible to manufacture MOS type semiconductor memory devices that have both the operating performance and high reliability at the same time.
  • FIG. 14 is a cross-sectional view showing a schematic configuration of the MOS type semiconductor memory device 60 1.
  • the MOS type semiconductor memory device 6 0 1 includes a p-type silicon substrate 10 0 1 as a semiconductor layer and a plurality of layers formed on the p-type silicon substrate 1 0 1 and having different band gap sizes.
  • first insulating film 1 1 1, second insulating film 1 1 2, third insulating film 1 1 3, fourth insulating film 1 1 4, and fifth insulating film 1 1 5 are provided between the silicon substrate 1 0 1 and the gate electrode 1 0 3.
  • first insulating film 1 1 1, second insulating film 1 1 2, third insulating film 1 1 3, fourth insulating film 1 1 4, and fifth insulating film 1 1 5 are provided between the silicon substrate 1 0 1 and the gate electrode 1 0 3, there is a first insulating film 1 1 1, second insulating film 1 1 2, third insulating film 1 1 3, fourth insulating film 1 1 4, and fifth insulating film 1 1 5 are provided.
  • the second insulating film 1 1 2, the third insulating film 1 1 3, and the fourth insulating film 1 1 4 are all silicon nitride films, and the silicon nitride film stack 100 2 a is Forming.
  • the silicon substrate 10 1 1 includes a first source / drain 10 4 and a second source that are n-type diffusion layers at a predetermined depth from the surface so as to be located on both sides of the gate electrode 103.
  • One drain 10 5 is formed, and a channel forming region 10 6 is formed between the two.
  • the M O S type semiconductor memory device 60 1 may be formed in a P-well or p-type silicon layer formed in the semiconductor substrate.
  • an n-channel MOS device will be described as an example, but a P-channel MOS device may be used. Accordingly, the contents of the present embodiment described below can be applied to all n-channel MOS devices and P-channel MOS devices.
  • the first insulating film 1 1 for example silicon dioxide film formed by oxidizing the silicon substrate 1 0 1 of the surface thermal acid Act (S i 0 2 film).
  • the band gap size of the first insulating film 1 1 1 is in the range of 8 to 10 eV, for example, and the film thickness is preferably in the range of 0, 5 nm to 20 nm, for example, 1 nm to More preferably within the range of 3 nm.
  • the second insulating film 1 1 2 constituting the silicon nitride film laminate 1 0 2 a is a silicon nitride film (S i N film; where S i is formed on the surface of the first insulating film 1 1 1 .
  • the composition ratio of N and N is not necessarily determined stoichiometrically, and takes different values depending on the film formation conditions (the same applies hereinafter).
  • Second absolute The band gap size of the edge film 1 1 2 is in the range of 5 to 7 eV, for example, and the film thickness is preferably in the range of 2 nm to 20 nm, for example, and in the range of 3 nm to 5 nm. More preferred.
  • the third insulating film 1 13 is a silicon nitride film (SiN film) formed on the second insulating film 1 12.
  • the band gap size of the third insulating film 1 1 3 is in the range of 2.5 to 4 eV, for example, and the film thickness is preferably in the range of 2 nm to 30 nm, for example, 4 nm to l A range of 0 nm is more preferable.
  • the fourth insulating film 1 14 is a silicon nitride film (SiN film) formed on the third insulating film 1 13.
  • the fourth insulating film 1 14 has the same energy band gap and film thickness as the second insulating film 1 1 2, for example.
  • the fifth insulating film 1 15 is a silicon dioxide film (S i 0 2 film) deposited on the fourth insulating film 1 14 by, for example, the C VD method.
  • the fifth insulating film 115 functions as a blocking layer (barrier layer) between the electrode 103 and the fourth insulating film 114.
  • the band gap size of the fifth insulating film 1 1 5 is in the range of 8 to 10 eV, for example, and the film thickness is, for example, 2 ⁇ ! The range of ⁇ 30 nm is preferable, and the range of 5 nm to 8 nm is more preferable.
  • the gate electrode 103 is made of, for example, a polycrystalline silicon film formed by the CVD method, and functions as a control gate (CG) electrode.
  • the gate electrode 103 may be a film containing a metal such as W, Ti, Ta, Cu, A1, Au, and Pt.
  • Gate electrode 1 0 3 is not limited to a single layer, but for the purpose of lowering the specific resistance of the gate electrode 103 and increasing the operating speed of the MOO type semiconductor memory device 601, for example, tungsten, molybdenum, tantalum, titanium, A laminated structure including platinum, silicide, alloy, etc. of platinum can also be used.
  • the gate electrode 103 is connected to a wiring layer (not shown).
  • the silicon nitride film laminated body 10 composed of the second insulating film 1 1 2, the third insulating film 1 13 and the fourth insulating film 1 1 4. 2 a is a charge accumulation region that mainly accumulates charges. Therefore, in forming the second insulating film 1 1 2, the third insulating film 1 1 3, and the fourth insulating film 1 1 4, the manufacture of the silicon nitride film according to the first embodiment of the present invention By applying the method and controlling the size of the band gap of each film, the data write performance and data retention performance of the MOS semiconductor memory device 61 can be adjusted.
  • the second insulating film 1 1 2, the third insulating film 1 1 3, and the fourth insulating film 1 are applied by applying the method for manufacturing the silicon nitride film laminated body according to the second embodiment of the present invention.
  • 14 can be continuously produced in the same processing vessel by changing the silicon-containing compound gas / nitrogen gas flow rate ratio while maintaining the processing pressure constant in the plasma C VD apparatus 100.
  • the second insulating film 1 1 2, the third insulating film 1 1 3, and the fourth insulating film 1 1 are applied by applying the method for manufacturing the silicon nitride film laminate according to the third embodiment of the present invention. It is also possible to manufacture continuously in the same processing container by changing the magnitude of the RF bias applied to the wafer W in the plasma CVD apparatus 200 so that 4 has different band gaps.
  • the third An insulating film 1 1 3 and a fourth insulating film 1 1 4 are sequentially formed.
  • the conditions of the plasma C VD are adjusted so that the band gap is an arbitrary size, for example, in the range of 5 to 7 eV.
  • plasma C VD is performed under conditions different from the conditions for forming the second insulating film 1 1 2, and the band gap is 2.5 eV to 4 eV, for example. Adjust the plasma C VD condition so that it is within the range of.
  • the pressure conditions differ from the conditions for forming the third insulating film 1 1 3, for example, under the same pressure conditions as for forming the second insulating film 1 1 2.
  • Plasma CVD is performed, and the plasma CVD conditions are adjusted so that the band gap is in the range of 5 to 7 eV, for example.
  • the size of the band gap of each film can be controlled by changing the silicon-containing compound gas Z nitrogen gas flow rate ratio while keeping the plasma C VD treatment pressure constant.
  • a fifth insulating film 1 1 5 is formed on the fourth insulating film 1 1 4.
  • the fifth insulating film 1 1 5 is formed by, for example, the C VD method. be able to.
  • a polysilicon film, a metal layer, a metal silicide layer, or the like is formed on the fifth insulating film 115 by, for example, the C VD method to form a metal film to be the gate electrode 103. .
  • the metal film and the fifth insulating film 115 to the first insulating film 1111 are etched using the patterned resist as a mask.
  • a gate laminated structure having the formed gate electrode 103 and a plurality of insulating films is obtained.
  • n-type impurities are ion-implanted at a high concentration into the silicon surface adjacent to both sides of the gate stacked structure, and the first source and drain 10 4 and the second source and drain 10 5 are connected. Form. In this way, the MOS type semiconductor memory device 60 1 having the structure shown in FIG. 14 can be manufactured.
  • the second insulating film 1 1 2 and the fourth insulating film 1 1 4 are compared with the band gap of the third insulating film 1 1 3 in the silicon nitride film stack 10 2 a.
  • the band gap is formed large, the band gap of the third insulating film 1 13 may be made larger than the band gap of the second insulating film 1 1 2 and the fourth insulating film 1 1 4.
  • the band gaps of the second insulating film 1 1 2 and the fourth insulating film 1 1 4 do not need to be the same.
  • the silicon nitride film laminated body 10 2 a is exemplified as the case where the silicon nitride film laminated body 10 3 a has three layers including the second insulating film 1 1 2 to the fourth insulating film 1 1 4.
  • the method of the present invention can also be applied to the manufacture of a MOS type semiconductor memory device having a silicon nitride film laminated body in which two or more silicon nitride films are laminated. (0 1 2 8)
  • the present invention is not limited to the above-described embodiments, and various modifications can be made.
  • nitrogen gas or ammonia gas and disilane are used as the film forming source gas as an example.
  • nitrogen gas or ammonia gas and another silicon-containing compound gas for example, Even if silane, trisilane, trisilylamine, etc. are used, the ratio of Si / N contained in the film is controlled by changing the flow rate ratio of silicon-containing compound gas Z nitrogen gas or ammonia. It is possible to control the size of the band gap of the silicon nitride film.

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Abstract

Disclosed is a plasma CVD device (100). In the plasma CVD device (100), in producing a silicon nitride film while controlling the size of a band gap by CVD, microwaves are introduced into a treatment vessel (1) by a flat antenna (31) having a plurality of holes. The plasma CVD is carried out under a given treatment pressure selected from a pressure range of not less than 0.1 Pa and not more than 1333 Pa at a flow ratio between a silicon-containing compound gas and a nitrogen gas (silicon-containing compound gas flow rate/nitrogen gas flow rate) selected from a range of not less than 0.005 and not more than 0.2, whereby the Si/N ratio in the film is controlled to form a silicon nitride film having a band gap size of not less than 2.5 eV and not more than 7 eV.

Description

窒化珪素膜の製造方法、 窒化珪素膜積層体の製造方法、 コンビユー 夕読み取り可能な記憶媒体およびプラズマ C V D装置 Method for manufacturing silicon nitride film, method for manufacturing silicon nitride film laminate, combination readable storage medium and plasma C V D apparatus
技術分野 Technical field
( 0 0 0 1 )  (0 0 0 1)
明  Light
本発明は、 窒化珪素膜およびその積層体の製造方法、 これらの方 田  The present invention relates to a method for producing a silicon nitride film and a laminate thereof,
法に用いるコンピュータ読み取り可能な記憶媒体およびプラズマ c 書 Computer readable storage medium and plasma c letter
V D装置に関する。  Regarding V D equipment.
背景技術 Background art
( 0 0 0 2 )  (0 0 0 2)
現在、 電気的書換え動作が可能な E E P R OM ( E 1 e c t r i c a 1 1 y E r a s a b l e a n d P r o g r a mm a b l e R OM) などに代表される不揮発性半導体メモリ装置としては、 S ONO S ( S i 1 i c o n - O x i d e -N i t r i d e - O x i d e— S i 1 i c o n ) 型や MONO S (M e t a l - O x i d e — N i t r i d e— O x i d e— S i 1 i c o n ) 型と呼ばれる積 層構造を有するものがある。 これらのタイプの不揮発性半導体メモ リ装置では、 二酸化珪素膜 （O x i d e ) に挟まれた 1層以上の窒 化珪素膜 （N i t r i d e ) を電荷蓄積領域として情報の保持が行 われる。 つまり、 上記不揮発性半導体メモリ装置では、 半導体基板 ( S i 1 i c o n ) とコントロールゲート電極 （ S i 1 i c o nま たは M e t a 1 ) との間に電圧を印加することによって、 電荷蓄積 領域の窒化珪素膜に電子を注入してデータを保存したり、 窒化珪素 膜に蓄積された電子を除去したり して、 データの保存と消去の書換 えを行っている。 窒化珪素膜の電荷蓄積能力は、 そのバンドギヤッ プ構造と関係があると考えられる。 Non-volatile semiconductor memory devices such as EEPR OM (E 1 ectrica 1 1 y E rasable and Programmable R OM) that can be electrically rewritten are currently S ONO S (S i 1 icon-O Some have a layered structure called the xide -N itride -O xide—S i 1 icon) type or the MONO S (Metal-O xide —N itride—O xide—S i 1 icon) type. In these types of non-volatile semiconductor memory devices, information is retained by using one or more silicon nitride films (Nitride) sandwiched between silicon dioxide films (O xide) as charge storage regions. In other words, in the nonvolatile semiconductor memory device described above, a voltage is applied between the semiconductor substrate (S i 1 icon) and the control gate electrode (S i 1 icon or M eta 1), thereby nitriding the charge storage region. Rewriting data storage and erasure by injecting electrons into the silicon film and storing data, or removing electrons accumulated in the silicon nitride film I'm doing it. The charge storage capacity of silicon nitride film is thought to be related to its bandgap structure.
( 0 0 0 3 )  (0 0 0 3)
不揮発性半導体メモリ装置の電荷蓄積領域としての窒化珪素膜を 形成する技術として、 特許文献 1では、 トンネル酸化膜と トップ酸 化膜との間の窒化珪素膜を形成する際に、 ジクロルシラン （ S i H 2 C 12) とアンモニア （NH3) を原料ガスとし、 流量比 S i H2 C 1 2ZNH3を 1 Z 1 0以下の条件で減圧 C V D (Chemical Vapor D epos it ion； 化学気相堆積） 法により成膜する窒化珪素膜の形成方 法が記載されている。 しかし、 従来の C VD法による成膜プロセス の場合、 個々の窒化珪素膜のバンドギャップをプロセス条件のみに よって制御することは困難であった。 従来は窒化珪素膜のバンドギ ヤップの大きさを制御するために、 C VD法を利用して窒化珪素膜 を形成した後、 この窒化珪素膜を酸化して窒化酸化珪素膜に変化さ せるなど、 膜の構成成分自体を変化させる必要があった。 酸化処理 によって窒化珪素膜の膜質を変化させるには、 複数の成膜装置が必 要になってしまい、 プロセス効率が低下する。 特に、 電荷蓄積領域 として機能する窒化珪素膜を 2層以上の積層体 （窒化珪素膜積層体 ) として形成する場合、 工程が複雑になり、 プロセス効率がさらに 低下してしまうという問題があった。 As a technique for forming a silicon nitride film as a charge storage region of a nonvolatile semiconductor memory device, Patent Document 1 discloses that when forming a silicon nitride film between a tunnel oxide film and a top oxide film, dichlorosilane (S i H 2 C 1 2 ) and ammonia (NH 3 ) as source gas, flow rate ratio Si H 2 C 1 2 ZNH 3 is reduced to 1 Z 10 or less under reduced pressure CVD (Chemical Vapor Deposition) A method of forming a silicon nitride film formed by the deposition method is described. However, in the case of the conventional CVD deposition process, it was difficult to control the band gap of each silicon nitride film only by the process conditions. Conventionally, in order to control the band gap of the silicon nitride film, after forming a silicon nitride film using the CVD method, the silicon nitride film is oxidized to change into a silicon nitride oxide film. It was necessary to change the components of the membrane itself. In order to change the film quality of the silicon nitride film by the oxidation treatment, a plurality of film forming apparatuses are required, and the process efficiency is lowered. In particular, when a silicon nitride film functioning as a charge storage region is formed as a laminate of two or more layers (silicon nitride film laminate), there is a problem that the process becomes complicated and the process efficiency further decreases.
( 0 0 0 4 )  (0 0 0 4)
また、 プラズマ C VD法によって窒化珪素膜を形成することが一 般的に行われているが、 この方法で製造される窒化珪素膜は、 多く の場合、 エッチングのハードマスクゃス トッパー膜として使用され る、 緻密で欠陥が少ない良質な窒化珪素膜であった。  In addition, a silicon nitride film is generally formed by a plasma C VD method, but the silicon nitride film produced by this method is often used as an etching hard mask stopper film. It was a high-quality silicon nitride film that was dense and had few defects.
( 0 0 0 5 )  (0 0 0 5)
特許文献 1 特開平 5 - 1 4 5 0 7 8号公報 （例えば、 段落 0 0 1 5など） 発明の開示 Patent Document 1 Japanese Patent Application Laid-Open No. 5-1 4 5 0 78 (for example, paragraph 0 0 1 5 etc.) Disclosure of Invention
発明が解決しょうとする課題 Problems to be solved by the invention
( 0 0 0 6 )  (0 0 0 6)
本発明は上記実情に鑑みてなされたものであり、 その第 1の目的 は、 C V D法によりバンドギャップの大きさを容易に制御できる窒 化珪素膜の製造方法を提供することである。 また、 本発明の第 2の 目的は、 C VD法により個々の窒化珪素膜のバンドギャップの大き さを変えて窒化珪素膜積層体を容易に製造できる方法を提供するこ とである。 課題を解決するための手段  The present invention has been made in view of the above circumstances, and a first object thereof is to provide a method for manufacturing a silicon nitride film in which the size of the band gap can be easily controlled by the CVD method. The second object of the present invention is to provide a method for easily manufacturing a silicon nitride film laminate by changing the band gap size of each silicon nitride film by the CVD method. Means for solving the problem
( 0 0 0 7 )  (0 0 0 7)
本発明の窒化珪素膜の製造方法は、 複数の孔を有する平面アンテ ナにより処理室内にマイクロ波を導入してプラズマを生成するブラ ズマ C VD装置を用い、 被処理体上にプラズマ C VD法によって窒 化珪素膜を形成する窒化珪素膜の製造方法であって、  The method for producing a silicon nitride film of the present invention uses a plasma C VD apparatus that generates plasma by introducing microwaves into a processing chamber using a planar antenna having a plurality of holes, and uses a plasma C VD method on a workpiece. A silicon nitride film manufacturing method for forming a silicon nitride film by:
窒素ガスまたはアンモニアガスのいずれか一方とシリコン含有化合 物ガスとを含む成膜ガスを用い、 処理圧力を 0. 1 P a以上 1 3 3 3 P a以下の範囲内で一定に設定し、 前記成膜ガスが窒素ガスを含 む場合シリコン含有化合物ガスと窒素ガスとの流量比 （シリコン含 有化合物ガス流量 Z窒素ガス流量） を 0. 0 0 5以上 0. 2以下の 範囲内から選択し、 前記成膜ガスがアンモニアガスを含む場合シリ コン含有化合物ガスとアンモニアガスとの流量比 （シリコン含有化 合物ガス流量 アンモニアガス流量） を 0. 0 1 5以上 0. 2以下 の範囲内から選択して、 プラズマ C V Dを行い、 バンドギャップの 大きさが 2. 5 e V以上 7 e V以下の範囲内の窒化珪素膜を形成す る C VD工程を備えている。 Using a film-forming gas containing either nitrogen gas or ammonia gas and a silicon-containing compound gas, the processing pressure is set constant within a range of 0.1 Pa to 1 3 3 3 Pa, When the deposition gas contains nitrogen gas, select the flow rate ratio between silicon-containing compound gas and nitrogen gas (silicon-containing compound gas flow rate Z nitrogen gas flow rate) within the range of 0.005 to 0.2. When the film-forming gas contains ammonia gas, the flow rate ratio between the silicon-containing compound gas and the ammonia gas (silicon-containing compound gas flow rate, ammonia gas flow rate) is within the range of 0.015 to 0.2. Select, perform plasma CVD, and bandgap A C VD process for forming a silicon nitride film with a size in the range of 2.5 eV to 7 eV is provided.
( 0 0 0 8 )  (0 0 0 8)
本発明の窒化珪素膜の製造方法において、 処理圧力を 0. l P a 以上 4 P a以下の範囲内または 4 0 P a以上 1 3 3 3 P a以下の範 囲内で一定に設定することが好ましい。  In the method for producing a silicon nitride film of the present invention, the processing pressure may be set constant within a range of 0.1 l Pa to 4 Pa or 40 Pa to 1 3 3 3 Pa. preferable.
( 0 0 0 9 )  (0 0 0 9)
また、 本発明の窒化珪素膜の製造方法において、 被処理体に高周 波をパワー密度 0. O l WZ c m2以上 0. 6 4 W/ c m2以下の範 囲内で供給することが好ましい。 In the method for producing a silicon nitride film of the present invention, it is preferable that a high frequency is supplied to the object to be processed within a power density range of 0. Ol WZ cm 2 or more and 0.64 W / cm 2 or less.
( 0 0 1 0 )  (0 0 1 0)
本発明の窒化珪素膜積層体の製造方法は、 複数の孔を有する平面 アンテナにより処理室内にマイクロ波を導入してプラズマを生成す るプラズマ C VD装置を用い、 被処理体上にプラズマ C VD法によ つて窒化珪素膜の積層体を形成する窒化珪素膜積層体の製造方法で あって、  The method for producing a silicon nitride film laminate of the present invention uses a plasma C VD apparatus that generates plasma by introducing microwaves into a processing chamber using a planar antenna having a plurality of holes, and the plasma C VD is formed on the object to be processed. A method for manufacturing a silicon nitride film laminate in which a silicon nitride film laminate is formed by a method,
窒素ガスまたはアンモニアガスのいずれか一方とシリコン含有化 合物ガスとを含む成膜ガスを用い、 処理圧力を 0. l P a以上 1 3 3 3 P a以下の範囲内で一定に設定し、 前記成膜ガスが窒素ガスを 含む場合シリコン含有化合物ガスと窒素ガスとの流量比 （シリコン 含有化合物ガス流量/窒素ガス流量） を 0. 0 0 5以上 0. 2以下 の範囲内から選択し、 前記成膜ガスがアンモニアガスを含む場合シ リコン含有化合物ガスとアンモニアガスとの流量比 （シリコン含有 化合物ガス流量/アンモニアガス流量） を 0. 0 1 5以上 0. 2以 下の範囲内から選択して、 プラズマ C VDを行い、 2. 5 e V以上 7 e V以下の範囲内の第 1 のバンドギャップを有する窒化珪素膜を 形成する第 1の C VD工程と、 前記第 1の C V D工程の前または後に、 窒素ガスまたはアンモニ ァガスのいずれか一方とシリコン含有化合物ガスとを含む成膜ガス を用い、 前記第 1の C V D工程と同じ処理圧力で、 前記成膜ガスが 窒素ガスを含む場合シリコン含有化合物ガスと窒素ガスとの流量比 (シリコン含有化合物ガス流量/窒素ガス流量） を 0. 0 0 5以上 0. 2以下の範囲内で前記第 1の C VD工程とは異なる範囲に設定 し、 前記成膜ガスがアンモニアガスを含む場合シリコン含有化合物 ガスとアンモニアガスとの流量比 （シリコン含有化合物ガス流量 Z アンモニアガス流量） を 0. 0 1 5以上 0. 2以下の範囲内で前記 第 1 の C VD工程とは異なる範囲に設定することにより、 2. 5 e V以上 7 e V以下の範囲内で前記第 1のバンドギャップとは異なる 第 2のバンドギヤップを有する窒化珪素膜を形成する第 2の C VD 工程と、 Using a deposition gas containing either nitrogen gas or ammonia gas and a silicon-containing compound gas, the processing pressure is set to a constant value within the range of 0.1 l Pa to 1 3 3 3 Pa, When the film-forming gas contains nitrogen gas, the flow rate ratio between the silicon-containing compound gas and the nitrogen gas (silicon-containing compound gas flow rate / nitrogen gas flow rate) is selected from the range of 0.005 to 0.2. When the deposition gas contains ammonia gas, the flow rate ratio between silicon-containing compound gas and ammonia gas (silicon-containing compound gas flow rate / ammonia gas flow rate) is selected from the range of 0.0 1 5 or more and 0.2 or less Performing a plasma C VD, and forming a silicon nitride film having a first band gap in a range of 2.5 eV to 7 eV, Before or after the first CVD step, a film forming gas containing either nitrogen gas or ammonia gas and a silicon-containing compound gas is used, and the film forming gas is subjected to the same processing pressure as that in the first CVD step. The first C VD process within a range of flow rate ratio between silicon-containing compound gas and nitrogen gas (silicon-containing compound gas flow rate / nitrogen gas flow rate) of 0.005 or more and 0.2 or less. When the deposition gas contains ammonia gas, the flow ratio of silicon-containing compound gas to ammonia gas (silicon-containing compound gas flow rate Z ammonia gas flow rate) is not less than 0.0 1 5 0.2 The second band gap is different from the first band gap within the range of 2.5 eV or more and 7 eV or less by setting a range different from the first C VD process within the following range. Silicon nitride having A second C VD process to form a film;
を備えている。 この場合、 前記第 1 の C V D工程と前記第 2の C V D工程を繰り返し行うことが好ましい。 It has. In this case, it is preferable to repeat the first C V D step and the second C V D step.
( 0 0 1 1 )  (0 0 1 1)
本発明のコンピュータ読み取り可能な記憶媒体は、 コンピュータ 上で動作する制御プログラムが記憶されたコンピュー夕読み取り可 能な記憶媒体であって、  The computer-readable storage medium of the present invention is a computer-readable storage medium storing a control program that runs on a computer,
前記制御プログラムは、 実行時に、 複数の孔を有する平面アンテ ナにより処理室内にマイクロ波を導入してプラズマを生成させるプ ラズマ C VD装置を用い、 被処理体上にプラズマ C VD法によって 窒化珪素膜を形成するに際し、  The control program uses a plasma C VD apparatus in which a plasma is generated by introducing microwaves into a processing chamber by a planar antenna having a plurality of holes at the time of execution, and silicon nitride is formed on a workpiece by plasma C VD method. In forming the film,
窒素ガスまたはアンモニアガスのいずれか一方とシリコン含有化 合物ガスとを含む成膜ガスを用い、 処理圧力を 0. l P a以上 1 3 3 3 P a以下の範囲内で一定に設定し、 前記成膜ガスが窒素ガスを 含む場合シリコン含有化合物ガスと窒素ガスとの流量比 （シリコン 含有化合物ガス流量/窒素ガス流量） を 0. 0 0 5以上 0. 2以下 の範囲内から選択し、 前記成膜ガスがアンモニアガスを含む場合シ リコン含有化合物ガスとアンモニアガスとの流量比 （シリコン含有 化合物ガス流量 Zアンモニアガス流量） を 0. 0 1 5以上 0. 2以 下の範囲内から選択して、 プラズマ C V Dを行い、 バンドギャップ の大きさが 2. 5 e V以上 7 e V以下の範囲内の窒化珪素膜を形成 する C V D工程が行われるように、 コンピュータに前記プラズマ C VD装置を制御させるものである。 Using a deposition gas containing either nitrogen gas or ammonia gas and a silicon-containing compound gas, the processing pressure is set to a constant value within the range of 0.1 l Pa to 1 3 3 3 Pa, When the film forming gas contains nitrogen gas, the flow rate ratio of silicon-containing compound gas and nitrogen gas (silicon (Contained compound gas flow rate / nitrogen gas flow rate) is selected from the range of 0.005 or more and 0.2 or less, and when the film-forming gas contains ammonia gas, the flow rate ratio of silicon-containing compound gas and ammonia gas ( Select the compound gas flow rate (Z-ammonia gas flow rate) containing silicon from a range of 0.0 1 5 or more and 0.2 or less, perform plasma CVD, and the band gap size is 2.5 eV or more 7 eV The plasma C VD apparatus is controlled by a computer so that a CVD process for forming a silicon nitride film within the following range is performed.
( 0 0 1 2 )  (0 0 1 2)
本発明のプラズマ C VD装置は、 プラズマ C VD法により被処理 体上に窒化珪素膜を形成するプラズマ C VD装置であって、  The plasma C VD apparatus of the present invention is a plasma C VD apparatus for forming a silicon nitride film on a workpiece by a plasma C VD method,
被処理体を載置台に載置して収容する処理室と、  A processing chamber for storing the object to be processed on the mounting table;
前記処理室の前記開口部を塞ぐ誘電体部材と、  A dielectric member that closes the opening of the processing chamber;
前記誘電体部材の外側に設けられ、 前記処理室内にマイクロ波を 導入するための複数の孔を有する平面アンテナと、  A planar antenna provided outside the dielectric member and having a plurality of holes for introducing microwaves into the processing chamber;
前記処理室内に原料ガスを供給するガス供給装置と、  A gas supply device for supplying a source gas into the processing chamber;
前記処理室内を減圧排気する排気装置と、  An exhaust device for evacuating the processing chamber under reduced pressure;
窒素ガスまたはアンモニアガスのいずれか一方とシリコン含有化 合物ガスとを含む成膜ガスを用い、 処理圧力を 0. 1 P a以上 1 3 3 3 P a以下の範囲内で一定に設定し、 前記成膜ガスが窒素ガスを 含む場合シリコン含有化合物ガスと窒素ガスとの流量比 （シリコン 含有化合物ガス流量 窒素ガス流量） を 0. 0 0 5以上 0. 2以下 の範囲内から選択し、 前記成膜ガスがアンモニアガスを含む場合シ リコン含有化合物ガスとアンモニアガスとの流量比 （シリコン含有 化合物ガス流量/アンモニアガス流量） を 0. 0 1 5以上 0. 2以 下の範囲内から選択して、 プラズマ C VDを行い、 バンドギャップ の大きさが 2. 5 e V以上 7 e V以下の範囲内の窒化珪素膜を形成 する C VD工程、 が行われるように制御する制御部と、 を備えている。 発明の効果 Using a film-forming gas containing either nitrogen gas or ammonia gas and a silicon-containing compound gas, the processing pressure is set constant within a range of 0.1 Pa to 1 3 3 3 Pa, When the film forming gas contains nitrogen gas, the flow rate ratio of silicon-containing compound gas to nitrogen gas (silicon-containing compound gas flow rate, nitrogen gas flow rate) is selected from the range of 0.005 to 0.2, When the deposition gas contains ammonia gas, select the flow rate ratio between silicon-containing compound gas and ammonia gas (silicon-containing compound gas flow rate / ammonia gas flow rate) within the range of 0.0 1 5 or more and 0.2 or less. Plasma C VD to form a silicon nitride film with a band gap in the range of 2.5 eV to 7 eV And a control unit for controlling the CVD process to be performed. The invention's effect
( 0 0 1 3 )  (0 0 1 3)
本発明の窒化珪素膜の製造方法によれば、 窒素ガスまたはアンモ ニァガスのいずれか一方とシリコン含有化合物ガスとを含む成膜ガ スを用い、 処理圧力を 0. l P a以上 1 3 3 3 P a以下の範囲内で 一定に設定し、 成膜ガスが窒素ガスを含む場合シリコン含有化合物 ガスと窒素ガスとの流量比 （シリコン含有化合物ガス流量/窒素ガ ス流量） を 0. 0 0 5以上 0. 2以下の範囲内から選択し、 成膜ガ スがアンモニアガスを含む場合シリコン含有化合物ガスとアンモニ ァガスとの流量比 （シリコン含有化合物ガス流量/アンモニアガス 流量） を 0. 0 1 5以上 0. 2以下の範囲内から選択して、 プラズ マ C V Dを行うことにより、 ノ ンドギャップの大きさ力 S 2. 5 e V 以上 7 e V以下の範囲内の窒化珪素膜を容易に製造することができ る。 本発明では、 主に原料ガスの流量比と処理圧力の選択によって バンドギャップの大小を容易に制御できることから、 様々なバンド ギヤップ構造を有する窒化珪素膜積層体を形成する場合に連続的な 成膜が可能になり、 プロセス効率に優れている。 図面の簡単な説明  According to the method for producing a silicon nitride film of the present invention, a film forming gas containing either nitrogen gas or ammonia gas and a silicon-containing compound gas is used, and the processing pressure is set to 0.1 l Pa or more 1 3 3 3 When the deposition gas contains nitrogen gas, the flow rate ratio of silicon-containing compound gas to nitrogen gas (silicon-containing compound gas flow rate / nitrogen gas flow rate) is set to 0.0. When the film forming gas contains ammonia gas, the flow rate ratio between silicon-containing compound gas and ammonia gas (silicon-containing compound gas flow rate / ammonia gas flow rate) is set to 0.0 1 5 A silicon nitride film within a range of S 2.5 eV to 7 eV can be easily manufactured by performing plasma CVD by selecting from the range of 0.2 or more and less than 0.2. can do. In the present invention, since the size of the band gap can be easily controlled mainly by selecting the flow rate ratio of the source gas and the processing pressure, continuous film formation is required when forming a silicon nitride film laminate having various band gap structures. Is possible, and process efficiency is excellent. Brief Description of Drawings
( 0 0 1 4 )  (0 0 1 4)
図 1は、 窒化珪素膜の形成に適したプラズマ C VD装置の一例を 示す概略断面図である。  FIG. 1 is a schematic cross-sectional view showing an example of a plasma CVD apparatus suitable for forming a silicon nitride film.
図 2は、 平面アンテナの構造を示す図面である。  Figure 2 shows the structure of a planar antenna.
図 3は、 制御部の構成を示す説明図である。 図 4 Aおよび図 4 Bは、 第 1 の実施の形態に係る窒化珪素膜の製 造方法の工程例を示す図面である。 FIG. 3 is an explanatory diagram showing the configuration of the control unit. FIG. 4A and FIG. 4B are drawings showing a process example of the method for manufacturing the silicon nitride film according to the first embodiment.
図 5は、 プラズマ C V Dにおけるシリコン含有化合物ガス Z窒素 ガス比とパンドギャップとの関係を示すグラフ図面である。  FIG. 5 is a graph showing the relationship between the silicon-containing compound gas Z-nitrogen gas ratio and the plasma gap in plasma C V D.
図 6 A〜図 6 Fは、 第 2の実施の形態に係る窒化珪素膜積層体の 製造方法の工程例を示す図面である。  FIG. 6A to FIG. 6F are drawings showing a process example of the method for manufacturing the silicon nitride film laminate according to the second embodiment.
図 7は、 窒化珪素膜の形成に適したプラズマ C V D装置の別の例 を示す概略断面図である。  FIG. 7 is a schematic cross-sectional view showing another example of a plasma C VD apparatus suitable for forming a silicon nitride film.
図 8 Aおよび図 8 Bは、 第 3の実施の形態に係る窒化珪素膜の製 造方法の工程例を示す図面である。  FIG. 8A and FIG. 8B are drawings showing a process example of the method for manufacturing the silicon nitride film according to the third embodiment.
図 9は、 R Fバイアスの出力密度と窒化珪素膜のバン ドギャップ との関係を処理圧力別に示すグラフ図面である。  FIG. 9 is a graph showing the relationship between the output density of the RF bias and the band gap of the silicon nitride film according to the processing pressure.
図 1 0は、 R Fバイアスの出力密度と窒化珪素膜のバンドギヤッ プとの関係を A r流量別に示すグラフ図面である。  FIG. 10 is a graph showing the relationship between the RF bias output density and the bandgap of the silicon nitride film for each Ar flow rate.
図 1 1 Aおよび 1 1 Bは、 第 4の実施の形態に係る窒化珪素膜の 製造方法の工程例を示す図面である。  FIGS. 11A and 11B are drawings showing a process example of the method for manufacturing the silicon nitride film according to the fourth embodiment.
図 1 2は、 プラズマ C V Dにおける処理圧力とバンドギャップと の関係を示すグラフである。  Figure 12 is a graph showing the relationship between the processing pressure and the band gap in plasma C V D.
図 1 3 A〜図 1 3 Fは、 第 5の実施の形態に係る窒化珪素膜積層 体の製造方法の工程例を示す図面である。  FIGS. 13A to 13 F are drawings showing process steps of the method for manufacturing the silicon nitride film laminated body according to the fifth embodiment.
図 1 4は、 本発明方法を適用可能な MO S型半導体メモリ装置の 概略構成を示す説明図である。 発明を実施するための形態  FIG. 14 is an explanatory diagram showing a schematic configuration of a MOS type semiconductor memory device to which the method of the present invention is applicable. BEST MODE FOR CARRYING OUT THE INVENTION
( 0 0 1 5 )  (0 0 1 5)
[第 1の実施の形態]  [First embodiment]
以下、 本発明の実施の形態について図面を参照して詳細に説明す る。 図 1 は、 本発明の窒化珪素膜の製造方法に利用可能なプラズマ C VD装置 1 0 0の概略構成を模式的に示す断面図である。 Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. The FIG. 1 is a cross-sectional view schematically showing a schematic configuration of a plasma C VD apparatus 100 that can be used in the method for producing a silicon nitride film of the present invention.
( 0 0 1 6 )  (0 0 1 6)
プラズマ C VD装置 1 0 0は、 複数のスロッ ト状の孔を有する平 面アンテナ、 特に R L S A (Radial Line Slot Antenna； ラジアル ラインスロッ トアンテナ） にて処理室内にマイクロ波を導入してプ ラズマを発生させることにより、 高密度かつ低電子温度のマイクロ 波励起プラズマを発生させ得る R L S Aマイクロ波プラズマ処理装 置として構成されている。 プラズマ C VD装置 1 0 0では、 1 X 1 01 Q〜 5 X 1 012/ c m3のプラズマ密度で、 かつ 0. 7〜 2 e V の低電子温度を有するプラズマによる処理が可能である。 従って、 プラズマ C VD装置 1 0 0は、 各種半導体装置の製造過程において プラズマ C VDによる窒化珪素膜の成膜処理の目的で好適に利用で きる。 The plasma C VD apparatus 100 uses a flat antenna with a plurality of slot-shaped holes, especially RLSA (Radial Line Slot Antenna) to introduce microwaves into the processing chamber. It is configured as an RLSA microwave plasma processing device that can generate microwave-excited plasma with high density and low electron temperature by generating it. In the plasma C VD apparatus 100, it is possible to process with plasma having a plasma density of 1 X 1 0 1 Q to 5 X 10 12 / cm 3 and a low electron temperature of 0.7 to 2 e V . Accordingly, the plasma C VD apparatus 100 can be suitably used for the purpose of forming a silicon nitride film by plasma C VD in the manufacturing process of various semiconductor devices.
( 0 0 1 7 )  (0 0 1 7)
プラズマ C VD装置 1 0 0は、 主要な構成として、 気密に構成さ れた処理容器 1 と、 処理容器 1内にガスを供給するガス供給装置 1 8 と、 処理容器 1内を減圧排気するための排気装置 2 4と、 処理容 器 1の上部に設けられ、 処理容器 1内にマイクロ波を導入するマイ クロ波導入機構 2 7 と、 これらプラズマ C VD装置 1 0 0の各構成 部を制御する制御部 5 0 と、 を備えている。  The plasma C VD apparatus 10 0 has, as main components, an airtight process vessel 1, a gas supply device 18 that supplies gas into the process vessel 1, and a vacuum exhaust in the process vessel 1. The exhaust device 24, the microwave introduction mechanism 27 for introducing microwaves into the processing vessel 1 and the components of the plasma C VD device 100 are controlled. And a control unit 5 0.
( 0 0 1 8 )  (0 0 1 8)
処理容器 1は、 接地された略円筒状の容器により形成されている 。 なお、 処理容器 1は角筒形状の容器により形成してもよい。 処理 容器 1は、 アルミニウム等の材質からなる底壁 l aと側壁 l bとを 有している。  The processing container 1 is formed of a substantially cylindrical container that is grounded. The processing container 1 may be formed of a rectangular tube-shaped container. The processing container 1 has a bottom wall l a and a side wall l b made of a material such as aluminum.
( 0 0 1 9 ) 処理容器 1の内部には、 被処理体であるシリコン基板などの半導 体ウェハ （以下、 単に 「ウェハ」 と記す） Wを水平に支持するため の載置台 2が設けられている。 載置台 2は、 熱伝導性の高い材質例 えば A 1 N等のセラミックスにより構成されている。 この載置台 2 は、 排気室 1 1の底部中央から上方に延びる円筒状の支持部材 3に より支持されている。 支持部材 3は、 例えば A 1 N等のセラミック スにより構成されている。 (0 0 1 9) Inside the processing container 1, a mounting table 2 is provided for horizontally supporting a semiconductor wafer (hereinafter simply referred to as “wafer”) W such as a silicon substrate which is an object to be processed. The mounting table 2 is made of a material having high thermal conductivity, such as ceramics such as A 1 N. The mounting table 2 is supported by a cylindrical support member 3 extending upward from the center of the bottom of the exhaust chamber 11. The support member 3 is made of ceramics such as A 1 N, for example.
( 0 0 2 0 )  (0 0 2 0)
また、 載置台 2には、 その外縁部をカバーし、 ウェハ Wをガイ ド するためのカバーリング 4が設けられている。 このカバーリ ング 4 は、 例えば石英、 A 1 N、 A 1 2 0 3、 S i N等の材質で構成された 環状部材である。 Further, the mounting table 2 is provided with a cover ring 4 for covering the outer edge portion thereof and guiding the wafer W. The covering 4 is an annular member made of a material such as quartz, A 1 N, A 1 2 0 3 , Si N or the like.
( 0 0 2 1 )  (0 0 2 1)
また、 載置台 2には、 温度調節機構としての抵抗加熱型のヒータ 5が埋め込まれている。 このヒー夕 5は、 ヒ一夕電源 5 aから給電 されることにより載置台 2 を加熱して、 その熱で被処理体であるゥ ェハ Wを均一に加熱する。  Further, a resistance heating type heater 5 as a temperature adjusting mechanism is embedded in the mounting table 2. In this heat 5, the mounting table 2 is heated by being supplied with power from the heat source 5 a, and the wafer W as the object to be processed is uniformly heated by the heat.
( 0 0 2 2 )  (0 0 2 2)
また、 載置台 2には、 熱電対 （T C ) 6が配備されている。 この 熱電対 6により、 温度計測を行うことにより、 ウェハ Wの加熱温度 を例えば室温から 9 0 0 °Cまでの範囲で制御可能となっている。  The mounting table 2 is provided with a thermocouple (TC) 6. By measuring the temperature with this thermocouple 6, the heating temperature of the wafer W can be controlled in the range from room temperature to 900 ° C., for example.
( 0 0 2 3 )  (0 0 2 3)
また、 載置台 2には、 ウェハ Wを支持して昇降させるためのゥェ ハ支持ピン （図示せず） を有している。 各ウェハ支持ピンは、 載置 台 2の表面に対して突没可能に設けられている。  Further, the mounting table 2 has wafer support pins (not shown) for supporting the wafer W and moving it up and down. Each wafer support pin is provided so as to protrude and retract with respect to the surface of the mounting table 2.
( 0 0 2 4 )  (0 0 2 4)
処理容器 1の底壁 1 aの略中央部には、 円形の孔 1 0が形成され ている。 底壁 l aには処理容器 1内と連通し、 下方に向けて突出す る排気室 1 1が設けられている。 この排気室 1 1 には、 排気管 1 2 が接続されており、 この排気管 1 2を介して排気装置 2 4に接続さ れている。 A circular hole 10 is formed in the approximate center of the bottom wall 1a of the processing vessel 1. ing. The bottom wall la is provided with an exhaust chamber 11 that communicates with the inside of the processing container 1 and protrudes downward. An exhaust pipe 1 2 is connected to the exhaust chamber 11, and is connected to the exhaust device 24 via the exhaust pipe 12.
( 0 0 2 5 )  (0 0 2 5)
処理容器 1の上部には開口部が形成され、 該開口部に処理容器 1 を開閉させる蓋体 （リツ ド） としての機能を有するプレート 1 3が 配置されている。 プレート 1 3の内周部が、 内側 （処理容器 1内の 空間） へ向けて突出し、 環状の支持部 1 3 aを形成している。  An opening is formed in the upper part of the processing container 1, and a plate 13 having a function as a lid (lid) for opening and closing the processing container 1 is disposed in the opening. The inner peripheral portion of the plate 13 protrudes toward the inside (the space in the processing container 1) to form an annular support portion 13a.
( 0 0 2 6 )  (0 0 2 6)
プレート 1 3には、 環状をなすガス導入孔 1 4が設けられている 。 また、 処理容器 1の側壁 1 bには、 ガス導入孔 1 5が設けられて いる。 つまり、 ガス導入孔 1 4および 1 5は、 上下 2段に設けられ ている。 各ガス導入孔 1 4および 1 5は成膜原料ガスやプラズマ励 起用ガスを供給するガス供給装置 1 8に接続されている。 なお、 ガ ス導入孔 1 4および 1 5はノズル状またはシャワーヘッ ド状に設け てもよい。 また、 ガス導入孔 1 4とガス導入孔 1 5を単一のシャヮ 一へッ ドに設けてもよい。  The plate 13 is provided with an annular gas introduction hole 14. Further, a gas introduction hole 15 is provided in the side wall 1 b of the processing container 1. That is, the gas introduction holes 14 and 15 are provided in two upper and lower stages. The gas introduction holes 14 and 15 are connected to a gas supply device 18 for supplying a film forming source gas and a plasma excitation gas. The gas introduction holes 14 and 15 may be provided in a nozzle shape or a shower head shape. Further, the gas introduction hole 14 and the gas introduction hole 15 may be provided in a single shutter head.
( 0 0 2 7 )  (0 0 2 7)
また、 処理容器 1の側壁 l bには、 プラズマ C V D装置 1 0 0 と 、 これに隣接する搬送室 （図示せず） との間で、 ウェハ Wの搬入出 を行うための搬入出口 1 6 と、 この搬入出口 1 6 を開閉するゲート バルブ 1 7 とが設けられている。  In addition, on the side wall lb of the processing chamber 1, a loading / unloading port 16 for loading / unloading the wafer W between the plasma CVD apparatus 100 and a transfer chamber (not shown) adjacent thereto, A gate valve 1 7 for opening and closing the loading / unloading port 16 is provided.
( 0 0 2 8 )  (0 0 2 8)
ガス供給装置 1 8は、 ガス供給源 （例えば、 窒素 （N ) 含有ガス 供給源 1 9 a、 シリコン （ S i ) 含有ガス供給源 1 9 b、 不活性ガ ス供給源 1 9 cおよびクリーニングガス供給源 1 9 d ) と、 配管 （ 例えば、 ガスライン 2 0 a、 2 0 b、 2 0 c、 2 0 d ) と、 流量制 御装置 （例えば、 マスフ口一コントローラ 2 1 a、 2 1 b、 2 1 c 、 2 0 d ) と、 バルブ （例えば、 開閉バルブ 2 2 a , 2 2 b、 2 2 c、 2 2 d ) とを有している。 窒素含有ガス供給源 1 9 aは、 上段 のガス導入孔 1 4に接続されている。 また、 シリコン含有化合物ガ ス供給源 1 9 b、 不活性ガス供給源 1 9 cおよびクリーニングガス 供給源 1 9 dは、 下段のガス導入孔 1 5に接続されている。 なお、 ガス供給装置 1 8は、 上記以外の図示しないガス供給源として、 例 えば処理容器 1内の雰囲気を置換する際に用いるパージガス供給源 等を有していてもよい。 The gas supply device 18 includes a gas supply source (for example, a nitrogen (N) -containing gas supply source 19a, a silicon (Si) -containing gas supply source 19b, an inert gas supply source 19c, and a cleaning gas. Source 19 d) and piping ( For example, gas lines 2 0 a, 2 0 b, 2 0 c, 2 0 d) and flow control devices (for example, mass port controllers 2 1 a, 2 1 b, 2 1 c, 2 0 d) and And valves (for example, on-off valves 2 2 a, 2 2 b, 2 2 c, 2 2 d). The nitrogen-containing gas supply source 19 a is connected to the upper gas introduction hole 14. The silicon-containing compound gas supply source 19 b, the inert gas supply source 19 c, and the cleaning gas supply source 19 d are connected to the lower gas introduction hole 15. Note that the gas supply device 18 may include a purge gas supply source used when replacing the atmosphere in the processing container 1 as a gas supply source (not shown) other than the above, for example.
( 0 0 2 9 )  (0 0 2 9)
本発明では、 成膜原料ガスである窒素含有ガスとして窒素ガス （ N2) を用いる。 また、 他の成膜原料ガスであるシリコン含有化合 物ガスとしては、 例えばシラン （ S i H 4 ) 、 ジシラン （ S i 2 H6 ) 、 トリシラン （ S i 3 H 8 ) 、 T S A (トリシリルアミン） などを 用いることができる。 この中でも、 特にジシラン （ S i 2H6) が好 ましい。 つまり、 窒化珪素膜のバンドギャップの大きさを制御する 目的には、 成膜原料ガスとして、 窒素ガスとジシランとを用いる組 み合わせが好ましい。 さらに、 不活性ガス'としては、 例えば？^2ガ スゃ希ガスなどを用いることができる。 希ガスは、 プラズマ励起用 ガスとして安定したプラズマの生成に役立つものであり、 例えば A rガス、 K rガス、 X eガス、 H eガスなどを用いることができる 。 また、 クリーニングガスとしては、 C 1 F3、 N F3、 H C 1 、 F 等を例示できる。 In the present invention, nitrogen gas (N 2 ) is used as a nitrogen-containing gas that is a film forming source gas. Other silicon-containing compound gases, which are film-forming source gases, include, for example, silane (S i H 4 ), disilane (S i 2 H 6 ), trisilane (S i 3 H 8 ), TSA (trisilylamine). ) Etc. can be used. Of these, disilane (S i 2 H 6 ) is particularly preferred. That is, for the purpose of controlling the size of the band gap of the silicon nitride film, a combination using nitrogen gas and disilane as the film forming source gas is preferable. In addition, as an inert gas? ^ 2 gas or rare gas can be used. The rare gas is useful for generating stable plasma as a plasma excitation gas. For example, Ar gas, Kr gas, Xe gas, and He gas can be used. Examples of the cleaning gas include C 1 F 3 , NF 3 , HC 1, F, and the like.
( 0 0 3 0 )  (0 0 3 0)
窒素含有ガスは、 ガス供給装置 1 8の窒素含有ガス供給源 1 9 a から、 ガスライン 2 0 aを介してガス導入部に至り、 ガス導入孔 1 4から処理容器 1内に導入される。 一方、 シリコン含有化合物ガス 、 不活性ガスおよびクリーニングガスは、 シリコン含有化合物ガス 供給源 1 9 b、 不活性ガス供給源 1 9 cおよびクリ一二ングガス供 給源 1 9 dから、 それぞれガスライン 2 0 b〜 2 0 dを介してガス 導入部に至り、 ガス導入孔 1 5から処理容器 1 内に導入される。 各 ガス供給源に接続する各々のガスライン 2 0 a〜 2 0 dには、 マス フローコントローラ 2 1 a〜 2 1 dおよびその前後の開閉バルブ 2 2 a〜 2 2 dが設けられている。 このようなガス供給装置 1 8の構 成により、 供給されるガスの切替えや流量等の制御が出来るように なっている。 なお、 A rなどのプラズマ励起用の希ガスは任意のガ スであり、 必ずしも成膜原料ガスと同時に供給する必要はない。 The nitrogen-containing gas is supplied from the nitrogen-containing gas supply source 1 9 a of the gas supply device 1 8 to the gas introduction part via the gas line 2 0 a and the gas introduction hole 1 4 is introduced into the processing container 1. On the other hand, the silicon-containing compound gas, the inert gas, and the cleaning gas are supplied from the silicon-containing compound gas supply source 19 b, the inert gas supply source 19 c, and the cleaning gas supply source 19 d, respectively. It reaches the gas introduction part via b to 20 d and is introduced into the processing container 1 from the gas introduction hole 15. Each gas line 20 a to 20 d connected to each gas supply source is provided with mass flow controllers 21 a to 21 d and opening / closing valves 2 2 a to 22 d before and behind the mass flow controllers 21 a to 21 d. With such a configuration of the gas supply device 18, the supplied gas can be switched and the flow rate can be controlled. Note that the rare gas for plasma excitation such as Ar is an arbitrary gas, and it is not always necessary to supply it simultaneously with the film forming source gas.
( 0 0 3 1 )  (0 0 3 1)
排気装置 2 4は 、 夕一ポ分子ポンプなどの真空ポンプ （図示省略 Exhaust device 2 4 is a vacuum pump such as a monomolecular pump (not shown)
) を備えている。 前記のように、 排気装置 2 4は 、 排気管 1 2を介 して処理容器 1 の排気室 1 1 に接続されている o この真空ポンプを 作動させることにより、 処理容器 1内のガスは 、 排気室 1 1の空間). As described above, the exhaust device 24 is connected to the exhaust chamber 11 of the processing container 1 via the exhaust pipe 12 o By operating this vacuum pump, the gas in the processing container 1 is Exhaust chamber 1 1 space
1 1 a内へ均一に流れ、 さらに空間 1 1 aから排気管 1 2を介して 外部へ排気される 。 これにより、 処理容器 1内を 、 例えば 0 . 1 31 1 Flows uniformly into 1 a, and is further exhausted from space 1 1 a through exhaust pipe 1 2. As a result, the inside of the processing container 1 is, for example, 0.13.
3 P aまで高速に減圧することが可能となつてい •3。 It is possible to depressurize to 3 Pa at high speed.
( 0 0 3 2 )  (0 0 3 2)
次に、 マイクロ波導入機構 2 7の構成について説明する。 マイク 口波導入機構 2 7は、 主要な構成として、 透過板 2 8、 平面アンテ ナ 3 1、 遅波材 3 3、 カバー部材 3 4、 導波管 3 7およびマイクロ 波発生装置 3 9を備えている。  Next, the configuration of the microwave introduction mechanism 27 will be described. Microphone mouth wave introduction mechanism 27 includes a transmission plate 28, a planar antenna 31, a slow wave material 33, a cover member 34, a waveguide 37, and a microwave generator 39 as main components. ing.
( 0 0 3 3 )  (0 0 3 3)
マイクロ波を透過する透過板 2 8は、 プレート 1 3において内周 側に張り出した支持部 1 3 a上に配備されている。 透過板 2 8は、 誘電体、 例えば石英や A 1 2 0 3、 A I N等のセラミックスから構成 されている。 この透過板 2 8 と支持部 1 3 aとの間は、 シール部材 2 9 を介して気密にシールされている。 したがって、 処理容器 1内 は気密に保持される。 The transmission plate 28 that transmits microwaves is disposed on a support portion 13 a that protrudes to the inner peripheral side of the plate 13. Transmission plate 2 8 Dielectric, is composed of, for example quartz or A 1 2 0 3, AIN, etc. of the ceramic. A space between the transmission plate 2 8 and the support portion 13 a is hermetically sealed through a seal member 29. Therefore, the processing container 1 is kept airtight.
( 0 0 3 4 )  (0 0 3 4)
平面アンテナ 3 1は、 透過板 2 8の上方において、 載置台 2 と対 向するように設けられている。 平面アンテナ 3 1 は、 円板状をなし ている。 なお、 平面アンテナ 3 1 の形状は、 円板状に限らず、 例え ば四角板状でもよい。 この平面アンテナ 3 1は、 プレート 1 3の上 端に係止されている。  The planar antenna 31 is provided above the transmission plate 28 so as to face the mounting table 2. The planar antenna 3 1 has a disk shape. The shape of the planar antenna 3 1 is not limited to a disk shape, and may be a square plate shape, for example. The planar antenna 31 is locked to the upper end of the plate 13.
( 0 0 3 5 )  (0 0 3 5)
平面アンテナ 3 1は、 例えば表面が金または銀メツキされた銅板 、 ニッケル板、 S U S板またはアルミニウム板から構成されている 。 平面アンテナ 3 1は、 マイクロ波を放射する多数のスロッ ト状の マイクロ波放射孔 3 2を有している。 マイクロ波放射孔 3 2は、 所 定のパターンで平面アンテナ 3 1 を貫通して形成されている。  The planar antenna 31 is made of, for example, a copper plate, a nickel plate, a SUS plate or an aluminum plate whose surface is plated with gold or silver. The planar antenna 31 has a number of slot-shaped microwave radiation holes 32 that radiate microwaves. The microwave radiation hole 3 2 is formed to penetrate the planar antenna 3 1 in a predetermined pattern.
( 0 0 3 6 )  (0 0 3 6)
個々のマイク口波放射孔 3 2は、 例えば図 2に示すように、 細長 い長方形状 （スロッ ト状） をなし、 隣接する 2つのマイクロ波放射 孔が対をなしている。 そして、 典型的には隣接するマイクロ波放射 孔 3 2が 「 T」 字状に配置されている。 また、 このように所定の形 状 （例えば T字状） に組み合わせて配置されたマイクロ波放射孔 3 2は、 さらに全体として同心円状に配置されている。 このようなマ イク口波放射孔 3 2の配置によって、 処理容器 1内に円偏波を生じ させ、 当該円偏波によるプラズマを生成させることが出来る。  As shown in FIG. 2, for example, each microphone mouth wave radiation hole 3 2 has an elongated rectangular shape (slot shape), and two adjacent microwave radiation holes form a pair. Typically, adjacent microwave radiation holes 32 are arranged in a “T” shape. Further, the microwave radiation holes 32 arranged in a predetermined shape (for example, T-shape) in this way are further arranged concentrically as a whole. With such an arrangement of the microphone mouth wave radiation holes 32, a circularly polarized wave can be generated in the processing container 1, and plasma generated by the circularly polarized wave can be generated.
( 0 0 3 7 )  (0 0 3 7)
マイクロ波放射孔 3 2の長さや配列間隔は、 マイクロ波の波長 （ P T/JP2009/057006 λ g ) に応じて決定される。 例えば、 マイクロ波放射孔 3 2の間隔 は、 A g Z 4から； l gとなるように配置される。 図 2においては、 同心円状に形成された隣接するマイクロ波放射孔 3 2 どう しの間隔 を△ !·で示している。 なお、 マイクロ波放射孔 3 2 の形状は、 円形 状、 円弧状等の他の形状であってもよい。 さらに、 マイクロ波放射 孔 3 2の配置形態は特に限定されず、 同心円状のほか、 例えば、 螺 旋状、 放射状等に配置することもできる。 Microwave radiation holes 3 2 The length and arrangement interval of microwave holes (microwave wavelength ( PT / JP2009 / 057006 λ g) For example, the interval between the microwave radiation holes 3 2 is arranged to be from A g Z 4; lg. In FIG. 2, the interval between adjacent microwave radiation holes 3 2 formed concentrically is indicated by Δ! The shape of the microwave radiation hole 3 2 may be another shape such as a circular shape or an arc shape. Further, the arrangement form of the microwave radiation holes 32 is not particularly limited, and the microwave radiation holes 32 can be arranged concentrically, for example, spirally, radially, or the like.
( 0 0 3 8 )  (0 0 3 8)
平面アンテナ 3 1 の上面には、 真空よりも大きい誘電率を有する 遅波材 3 3が設けられている。 この遅波材 3 3は、 真空中ではマイ クロ波の波長が長くなることから、 マイクロ波の波長を短く してプ ラズマを調整する機能を有している。  A slow wave material 33 having a dielectric constant larger than that of vacuum is provided on the upper surface of the planar antenna 3 1. This slow wave material 33 has a function of adjusting the plasma by shortening the wavelength of the microwave because the wavelength of the microwave becomes longer in vacuum.
( 0 0 3 9 )  (0 0 3 9)
なお、 平面アンテナ 3 1 と透過板 2 8 との間、 また、 遅波材 3 3 と平面アンテナ 3 1 との間は、 それぞれ接触させても離間させても よいが、 接触させることが好ましい。  Note that the planar antenna 3 1 and the transmission plate 28 and the slow wave material 3 3 and the planar antenna 3 1 may be contacted or separated from each other, but are preferably in contact with each other.
( 0 0 4 0 )  (0 0 4 0)
処理容器 1の上部には、 これら平面アンテナ 3 1および遅波材 3 3 を覆うように、 カバー部材 3 4が設けられている。 カバー部材 3 4は、 例えばアルミニウムやステンレス鋼等の金属材料によって形 成されている。 プレート 1 3の上端とカバ一部材 3 4とは、 シール 部材 3 5によりシールされている。 カバー部材 3 4の内部には、 冷 却水流路 3 4 aが形成されている。 この冷却水流路 3 4 aに冷却水 を通流させることにより、 カバ一部材 3 4、 遅波材 3 3、 平面アン テナ 3 1および透過板 2 8 を冷却し、 これらの部材の破損や変形を 防止できるようになつている。 なお、 カバー部材 3 4は接地されて いる。 ( 0 0 4 1 ) A cover member 3 4 is provided on the upper portion of the processing container 1 so as to cover the planar antenna 3 1 and the slow wave material 3 3. The cover member 34 is formed of a metal material such as aluminum or stainless steel. The upper end of the plate 13 and the cover member 3 4 are sealed by a seal member 3 5. Inside the cover member 3 4, a cooling water flow path 3 4 a is formed. By passing the cooling water through the cooling water flow path 3 4 a, the cover member 3 4, the slow wave material 3 3, the planar antenna 3 1 and the transmission plate 2 8 are cooled, and these members are damaged or deformed. Can be prevented. The cover member 34 is grounded. (0 0 4 1)
カバ一部材 3 4の上壁 （天井部） の中央には、 開口部 3 6が形成 されており、 この開口部 3 6には導波管 3 7が接続されている。 導 波管 3 7の他端側は、 マッチング回路 3 8を介してマイクロ波を発 生するマイクロ波発生装置 3 9が接続されている。  An opening 3 6 is formed at the center of the upper wall (ceiling) of the cover member 3 4, and a waveguide 3 7 is connected to the opening 3 6. The other end of the waveguide 37 is connected to a microwave generator 39 that generates a microwave via a matching circuit 38.
( 0 0 4 2 )  (0 0 4 2)
導波管 3 7は、 上記カバ一部材 3 4の開口部 3 6から上方へ延出 する断面円形状の同軸導波管 3 7 aと、 この同軸導波管 3 7 aの上 端部に接続された水平方向に延びる矩形導波管 3 7 bとを有してい る。  The waveguide 37 is formed of a coaxial waveguide 37a having a circular cross section extending upward from the opening 36 of the cover member 34, and an upper end of the coaxial waveguide 37a. And a rectangular waveguide 3 7 b extending horizontally.
( 0 0 4 3 )  (0 0 4 3)
同軸導波管 3 7 aの中心には内導体 4 1が延在している。 この内 導体 4 1は、 その下端部において平面アンテナ 3 1の中心に接続固 定されている。 同軸導波管 3 7 aは、 カバー部材 3 4と平面アンテ ナ 3 1 とで形成される、 放射状の偏平導波管に連通して形成されて いる。 このような構造により、 マイクロ波は、 同軸導波管 3 7 aの 内導体 4 1 を介して平面アンテナ 3 1へ放射状に効率よく均一に伝 播される。  An inner conductor 41 extends in the center of the coaxial waveguide 37a. The inner conductor 41 is connected and fixed to the center of the planar antenna 31 at the lower end thereof. The coaxial waveguide 3 7 a is formed in communication with a radial flat waveguide formed by the cover member 3 4 and the planar antenna 3 1. With such a structure, microwaves are efficiently and uniformly propagated radially and uniformly to the planar antenna 31 via the inner conductor 4 1 of the coaxial waveguide 37a.
( 0 0 4 4 )  (0 0 4 4)
以上のような構成のマイク口波導入機構 2 7により、 マイクロ波 発生装置 3 9で発生したマイクロ波が導波管 3 7 を介して平面アン テナ 3 1へ伝搬され、 さらに透過板 2 8 を介して処理容器 1内に導 入されるようになっている。 なお、 マイクロ波の周波数としては、 例えば 2 . 4 5 G H zが好ましく用いられ、 他に、 8 . 3 5 G H z 、 1 . 9 8 G H z等を用いることもできる。  By the microphone mouth wave introduction mechanism 27 having the above-described configuration, the microwave generated by the microwave generator 39 is propagated to the planar antenna 3 1 via the waveguide 37, and the transmission plate 28 is It is introduced into the processing container 1 via As the microwave frequency, for example, 2.45 GHz is preferably used, and 8.35 GHz, 1.9.8 GHz, or the like can also be used.
( 0 0 4 5 )  (0 0 4 5)
プラズマ C V D装置 1 0 0 の各構成部は、 制御部 5 0に接続され 57006 て制御される構成となっている。 制御部 5 0は、 コンピュータを有 しており、 例えば図 3に示したように、 C P Uを備えたプロセスコ ントロ一ラ 5 1 と、 このプロセスコントローラ 5 1 に接続されたュ 一ザ一インタ一フェース 5 2および記憶部 5 3 を備えている。 プロ セスコントローラ 5 1は、 プラズマ C V D装置 1 0 0において、 例 えば温度、 圧力、 ガス流量、 マイクロ波出力などのプロセス条件に 関係する各構成部 （例えば、 ヒー夕電源 5 a、 ガス供給装置 1 8、 排気装置 2 4、 マイクロ波発生装置 3 9など） を統括して制御する 制御手段である。 Each component of the plasma CVD apparatus 100 is connected to the controller 50. 57006 is controlled. The control unit 50 has a computer. For example, as shown in FIG. 3, the process controller 51 having a CPU and a user interface connected to the process controller 51 are used. A face 52 and a storage unit 53 are provided. In the plasma CVD apparatus 100, the process controller 51 is a component related to process conditions such as temperature, pressure, gas flow rate, and microwave output (for example, a heat source 5a, a gas supply apparatus 1). 8, exhaust system 24, microwave generator 39, etc.).
( 0 0 4 6 )  (0 0 4 6)
ユーザーィンタ—フェース 5 2は、 工程管理者がプラズマ C V D 装置 1 0 0 を管理するためにコマンドの入力操作等を行うキーポ一 ドゃ、 プラズマ C V D装置 1 0 0の稼働状況を可視化して表示する ディスプレイ等を有している。 また、 記憶部 5 3には、 プラズマ C V D装置 1 0 0で実行される各種処理をプロセスコントローラ 5 1 の制御にて実現するための制御プログラム （ソフ トウェア） や処理 条件データ等が記録されたレシピが保存されている。  The user interface 5 2 is a keypad for the process manager to input commands to manage the plasma CVD apparatus 10 0 0, etc. Etc. The storage unit 53 also has a recipe in which a control program (software) and processing condition data for realizing various processes executed by the plasma CVD apparatus 100 are controlled by the process controller 51. Is saved.
( 0 0 4 7 )  (0 0 4 7)
そして、 必要に応じて、 ユーザ一イン夕一フェース 5 2からの指 示等にて任意のレシピを記憶部 5 3から呼び出してプロセスコント 口一ラ 5 1 に実行させることで、 プロセスコントローラ 5 1 の制御 下、 プラズマ C V D装置 1 0 0の処理容器 1内で所望の処理が行わ れる。 また、 前記制御プログラムや処理条件データ等のレシピは、 コンピュータ読み取り可能な記憶媒体、 例えば C D— R〇M、 ハー ドディスク、 フレキシブルディスク、 フラッシュメモリ、 D V D、 ブルーレイディスクなどに格納された状態のものを利用したり、 あ るいは、 他の装置から、 例えば専用回線を介して随時伝送させてォ JP2009/057006 ンラインで利用したりすることも可能である。 Then, if necessary, the process controller 51 can call an arbitrary recipe from the storage unit 53 and execute it in the process controller 51 according to an instruction from the user interface 51. Under the control, a desired process is performed in the processing chamber 1 of the plasma CVD apparatus 100. The recipes such as the control program and processing condition data are stored in a computer-readable storage medium such as a CD-ROM, a hard disk, a flexible disk, a flash memory, a DVD, or a Blu-ray disc. Or from other devices, for example, via a dedicated line. JP2009 / 057006 can also be used on-line.
( 0 0 4 8 )  (0 0 4 8)
次に、 R L S A方式のプラズマ C VD装置 1 0 0 を用いたプラズ マ C VD法による窒化珪素膜の堆積処理について説明する。 まず、 ゲートバルブ 1 7 を開にして搬入出口 1 6からウェハ Wを処理容器 1内に搬入し、 載置台 2上に載置する。 次に、 処理容器 1内を減圧 排気しながら、 ガス供給装置 1 8の窒素含有ガス供給源 1 9 a、 シ リコン含有化合物ガス供給源 1 9 bおよび不活性ガス供給源 1 9 c から、 窒素ガス、 シリコン含有化合物ガスおよび必要に応じて希ガ スを所定の流量でそれぞれガス導入孔 1 4， 1 5を介して処理容器 1内に導入する。 このようにして、 処理容器 1内を所定の圧力に調 節する。  Next, a silicon nitride film deposition process by a plasma C VD method using an R L S A type plasma C VD apparatus 100 will be described. First, the gate valve 17 is opened, and the wafer W is loaded into the processing container 1 from the loading / unloading port 16 and mounted on the mounting table 2. Next, while depressurizing and exhausting the inside of the processing container 1, nitrogen is supplied from the nitrogen-containing gas supply source 19a, the silicon-containing compound gas supply source 19b and the inert gas supply source 19c of the gas supply device 18. Gas, silicon-containing compound gas, and if necessary, rare gas are introduced into the processing vessel 1 through the gas introduction holes 14 and 15 at predetermined flow rates, respectively. In this way, the inside of the processing container 1 is adjusted to a predetermined pressure.
( 0 0 4 9 )  (0 0 4 9)
次に、 マイクロ波発生装置 3 9で発生させた所定周波数例えば 2 . 4 5 GH zのマイクロ波を、 マッチング回路 3 8を介して導波管 3 7に導く。 導波管 3 7 に導かれたマイク口波は、 矩形導波管 3 7 bおよび同軸導波管 3 7 aを順次通過し、 偏平導波管へ放射状に伝 播され、 平面アンテナ板 3 1 に供給される。 つまり、 マイクロ波は 、 同軸導波管 3 7 a内を平面アンテナ板 3 1 に向けて伝搬していき 、 さらにカバ一部材 3 4と平面アンテナ 3 1 とで形成される偏平導 波管内を放射状に伝播したマイクロ波は、 平面アンテナ板 3 1のス ロッ ト状のマイクロ波放射孔 3 2から透過板 2 8 を介して処理容器 1内におけるウェハ Wの上方空間に放射させられる。 この際のマイ クロ波出力は、 透過板 2 8の面積あたりのパワー密度として 0. 2 5〜 2. 5 6 W/ c m2の範囲内とすることが好ましい。 マイクロ 波出力は、 例えば 5 0 0〜 5 0 0 0 Wの範囲内から目的に応じて上 記範囲内のパワー密度になるように選択することができる。 ( 0 0 5 0 ) Next, a microwave having a predetermined frequency, for example, 2.45 GHz, generated by the microwave generator 39 is guided to the waveguide 37 via the matching circuit 38. The microphone mouth wave guided to the waveguide 3 7 sequentially passes through the rectangular waveguide 3 7 b and the coaxial waveguide 3 7 a, is propagated radially to the flat waveguide, and the planar antenna plate 3 1 To be supplied. That is, the microwave propagates in the coaxial waveguide 37a toward the planar antenna plate 31, and further radiates in the flat waveguide formed by the cover member 34 and the planar antenna 31. The microwave propagated to the wafer is radiated from the slot-like microwave radiation hole 3 2 of the planar antenna plate 3 1 to the space above the wafer W in the processing chamber 1 through the transmission plate 2 8. The microwave output at this time is preferably in the range of 0.25 to 2.56 W / cm 2 as the power density per area of the transmission plate 28. The microwave output can be selected, for example, from the range of 500 to 500 W so that the power density is within the above range according to the purpose. (0 0 5 0)
平面アンテナ 3 1から透過板 2 8を経て処理容器 1 に放射された マイクロ波により、 処理容器 1内で電磁界が形成され、 窒素含有ガ ス、 シリコン含有化合物ガスがそれぞれプラズマ化する。 そして、 プラズマ中で原料ガスの解離が効率的に進み、 イオンゃラジカルな どの活性種、 例えば S i PHQ、 S i H NHい N (ここで、 p、 ciは任意の数を意味する。 以下同様である。 ） などの反応によって 、 窒化珪素 S i Nの薄膜が堆積される。 An electromagnetic field is formed in the processing container 1 by the microwave radiated from the planar antenna 31 to the processing container 1 through the transmission plate 28, and nitrogen-containing gas and silicon-containing compound gas are turned into plasma. Then, the dissociation of the source gas efficiently proceeds in the plasma, and active species such as ion radicals, such as S i P H Q , S i H NH i N (where p and ci mean any number) The same shall apply hereinafter.) A thin film of silicon nitride Si N is deposited by such a reaction.
( 0 0 5 1 )  (0 0 5 1)
上記構成を有するプラズマ C VD装置 1 0 0においては、 窒化珪 素膜を成膜する際のプラズマ C VD処理の圧力条件を一定にし、 シ リコン含有化合物ガスと窒素ガスとの流量比 （シリコン含有化合物 ガス/窒素ガス流量比） を 0. 0 0 5以上 0. 2以下の範囲内で変 化させることにより、 形成される窒化珪素膜のバンドギャップを 2 . 5 e V以上 7 e V以下の範囲内で所望の大きさにコントロールで きる。 例えば、 処理圧力が 0. 1 P a以上 4 P a以下の範囲内では 、 窒化珪素膜の形成反応はプリカーサ一であるシリコン含有化合物 分子の供給により律束される。 そのため、 窒素ガスに対するシリコ ン含有化合物ガスの比率が少ない場合は、 窒化珪素膜は相対的に窒 素リッチとなり、 エネルギーパンドギャップを大きくすることがで きる。 逆に、 0. 1 P a以上 4 P a以下の範囲内の圧力でシリコン 含有化合物ガスの比率を多く していく ことにより、 窒化珪素膜は相 対的にシリコンリ ッチになり、 エネルギーバンドギャップを小さく することができる。  In the plasma C VD apparatus 100 having the above-described configuration, the pressure condition of the plasma C VD treatment when forming the silicon nitride film is made constant, and the flow rate ratio between the silicon-containing compound gas and the nitrogen gas (silicon-containing By changing the compound gas / nitrogen gas flow rate ratio within the range of 0.005 to 0.2, the band gap of the silicon nitride film to be formed is 2.5 eV or more and 7 eV or less. The desired size can be controlled within the range. For example, when the processing pressure is in the range of 0.1 Pa to 4 Pa, the formation reaction of the silicon nitride film is restricted by the supply of silicon-containing compound molecules that are precursors. For this reason, when the ratio of the silicon-containing compound gas to the nitrogen gas is small, the silicon nitride film becomes relatively nitrogen-rich and the energy gap can be increased. Conversely, by increasing the ratio of the silicon-containing compound gas at a pressure in the range of 0.1 Pa or more and 4 Pa or less, the silicon nitride film becomes relatively silicon-rich and the energy band gap Can be reduced.
( 0 0 5 2 )  (0 0 5 2)
一方、 例えば処理圧力が 4 0 P a以上 1 3 3 3 P a以下の範囲内 では、 窒化珪素膜の形成は反応律束の傾向が強くなる。 そのため、 4 0 P a以上 1 3 3 3 P a以下の範囲内の圧力では、 シリコン含有 化合物ガスの比率を多く していっても、 窒化珪素膜はシリコンリツ チにはなりにく く、 むしろ相対的に窒素リ ッチになり、 エネルギー パンドギャップを大きくすることができる。 逆に、 窒素ガスに対す るシリコン含有化合物ガスの比率を少なく していく と、 窒化珪素膜 は相対的にシリコンリ ツチとなるため、 エネルギーバンドギャップ を小さくすることができる。 On the other hand, for example, when the processing pressure is in the range of 40 Pa or more and 1 3 3 3 Pa or less, the formation of the silicon nitride film has a strong tendency of reaction regulation. for that reason, At pressures in the range of 40 Pa or more and 1 3 3 3 Pa or less, even if the ratio of silicon-containing compound gas is increased, the silicon nitride film is not likely to be silicon-rich, but rather relative. It becomes a nitrogen-rich and can increase the energy span gap. Conversely, if the ratio of the silicon-containing compound gas to the nitrogen gas is reduced, the silicon nitride film becomes a relatively silicon rich, and the energy band gap can be reduced.
( 0 0 5 3 )  (0 0 5 3)
このように、 成膜原料ガス中の S i 2H6/N2流量比によって、 応答性よく窒化珪素膜中の窒素含有量やシリコン含有量を変化させ てバンドギャップの大きさをコントロールできることは、 プラズマ C VD装置 1 0 0の特徴である。 つまり、 I C Pなど他のプラズマ 方式の C VD装置や、 熱 C VD装置では、 成膜原料ガスの S i 2H6 /N2流量比を変化させても、 窒化珪素膜の組成は化学量論比 （ S i 3N4) から大きく変化することは少なく、 意図的に窒素リ ッチま たはシリコンリッチの膜を成膜することは事実上不可能であった。 従って、 従来のプラズマ C VD装置や熱 C VD装置では、 窒化珪素 膜のバンドギャップを精度よくコントロールすることはできなかつ た。 それに対し、 本発明では、 マイクロ波励起高密度プラズマを生 成できるプラズマ C VD装置 1 0 0を使用することによって、 成膜 原料ガス中の S i 2H6/N2流量比により、 窒化珪素膜中の S i / N比を制御性よく変化させ、 容易に目的の大きさのバンドギャップ を有する窒化珪素膜を成膜することができる。 In this way, it is possible to control the size of the band gap by changing the nitrogen content and silicon content in the silicon nitride film with high responsiveness according to the Si 2 H 6 / N 2 flow rate ratio in the film forming source gas. This is a feature of the plasma C VD device 100. In other words, in other plasma-type C VD devices such as ICP and thermal C VD devices, the composition of the silicon nitride film is stoichiometric even if the Si 2 H 6 / N 2 flow ratio of the film forming source gas is changed. The ratio (Si 3 N 4 ) did not vary greatly, and it was virtually impossible to intentionally form a nitrogen-rich or silicon-rich film. Therefore, the conventional plasma CVD apparatus and thermal CVD apparatus cannot accurately control the band gap of the silicon nitride film. On the other hand, in the present invention, by using a plasma C VD apparatus 100 that can generate microwave-excited high-density plasma, silicon nitride can be formed according to the Si 2 H 6 / N 2 flow rate ratio in the film forming raw material gas. By changing the Si / N ratio in the film with good controllability, it is possible to easily form a silicon nitride film having a target band gap.
( 0 0 5 4 )  (0 0 5 4)
図 4 Aおよび 4 Bは、 プラズマ C VD装置 1 0 0において行われ る窒化珪素膜の製造工程を示した工程図である。 図 4 Aに示したよ うに、 任意の下地層 （例えば二酸化珪素膜） 6 0の上に、 S i 2H6 P T/JP2009/057006 4A and 4B are process diagrams showing a silicon nitride film manufacturing process performed in the plasma C VD apparatus 100. As shown in Fig. 4A, on an arbitrary underlayer (eg, silicon dioxide film) 60, Si 2 H 6 PT / JP2009 / 057006
ZN2プラズマを用いて処理圧力でプラズマ C VD処理を行う。 こ のプラズマ C V D処理では、 シリコン含有化合物ガスと窒素ガスと を含む成膜ガスを用い、 処理圧力を 0. l P a以上 4 P a以下の範 囲内または 4 0 P a以上 1 3 3 3 P a以下の範囲内で一定にして、 シリコン含有化合物ガス/窒素ガス流量比を 0. 0 0 5以上 0. 2 以下の範囲内で制御する。 これにより、 図 4 Bに示したように、 2 . 5 e V以上 7 e V以下の範囲内の大きさのバンドギャップを有す る窒化珪素膜 7 0 を形成することができる。 Plasma C VD treatment is performed at a processing pressure using ZN 2 plasma. In this plasma CVD process, a film-forming gas containing a silicon-containing compound gas and nitrogen gas is used, and the process pressure is in the range of 0. l Pa to 4 Pa, or 40 Pa to 1 3 3 3 P. The flow rate ratio of silicon-containing compound gas / nitrogen gas is controlled within a range of not less than 0.005 and not more than 0.2 by making the value constant within a range of a or less. As a result, as shown in FIG. 4B, a silicon nitride film 70 having a band gap in the range of 2.5 eV to 7 eV can be formed.
( 0 0 5 5 )  (0 0 5 5)
次に、 本発明の基礎となった実験データについて説明する。 図 5 は、 窒素含有ガスとして N2ガス、 シリコン含有化合物ガスとして S i 2H6ガスを使用し、 プラズマ C VD装置 1 0 0 においてプラズ マ C VDを実施し、 単膜の窒化珪素膜を形成した場合の窒化珪素膜 のバンドギャップと処理圧力との関係を示している。 プラズマ C V D条件は以下のとおりである。 Next, experimental data on which the present invention is based will be described. In Fig. 5, N 2 gas is used as the nitrogen-containing gas, and Si 2 H 6 gas is used as the silicon-containing compound gas. Plasma C VD is performed in the plasma C VD apparatus 100, and a single silicon nitride film is formed. The relationship between the band gap of the silicon nitride film and the processing pressure when formed is shown. The plasma CVD conditions are as follows.
( 0 0 5 6 )  (0 0 5 6)
[プラズマ C VD条件]  [Plasma C VD condition]
処理温度 （載置台） ： 5 0 0 °C  Processing temperature (mounting table): 5 0 0 ° C
マイクロ波パワー ： 2 k W (パワー密度 1. 0 2 3 W/ c m2 ； 透過板面積あたり） Microwave power: 2 k W (power density 1.0 2 3 W / cm 2 ; per transmission plate area)
処理圧力 ； 2. 7 P a ( 2 0 mT o r r ) 、 6 6. 7 P a ( 5 0 0 m T o r r )  Processing pressure: 2. 7 Pa (20 mTorr), 66.7 Pa (50000 mTorr)
A rガス流量 ； 2 0 0 mLZm i n ( s c c m)  Ar gas flow rate; 20 0 mLZm i n (s c c m)
N2ガス流量 ； 2 0 O mL/m i n ( s c c m) N 2 gas flow rate; 20 O mL / min (sccm)
S i 2H6ガス流量 ； 2 mLZm i n ( s e c m) 、 4 m L / m i n ( s e c m) または 8 mL/m i n ( s e c m) S i 2 H 6 gas flow rate: 2 mLZm in (secm), 4 mL / min (secm) or 8 mL / min (secm)
( 0 0 5 7 ) なお、 窒化珪素膜のバンドギャップは、 薄膜特性測定装置 n & k • A n a l y z e r (商品名 ； n & kテクノロジ一社製） を用いて 計測した。 (0 0 5 7) The band gap of the silicon nitride film was measured using a thin film characteristic measuring apparatus n & k • Analyzer (trade name; manufactured by n & k Technology Co., Ltd.).
( 0 0 5 8 )  (0 0 5 8)
図 5に示したように、 プラズマ C VD装置 1 0 0 を用い、 窒素含 有ガスとして N2ガス、 シリコン含有化合物ガスとして S i 2H6ガ ス、 不活性ガスとして A rガスを使用し、 処理圧力を 2. 7 P a ( 2 0 mT o r r ) または 6 6. 7 P a ( 5 0 0 mT o r r ) に設定 して、 S i 2H6/N2流量比を 0. 0 1から 0. 0 4の範囲内で変 化させることにより、 成膜される窒化珪素膜のバンドギャップが約 4 , 8 e Vから 6. O e Vの範囲内で変化した。 つまり、 処理圧力 を一定にして S i 2H6/N2流量比を変化させることによって、 窒 化珪素膜中に含まれる S i ZNの比をコントロールして容易に所望 のバンドギャップを有する窒化珪素膜を形成することができる。 ま た、 図 5の結果から、 同じ S HeZNs流量比 （例えば、 S i 2 H 6ZN2流量比が 0. 0 1 または 0. 0 4 ) でも、 圧力を変化させる ことにより、 バンドギャップの大きさを調節できることがわかる。 なお、 比較のため、 同様に処理圧力を変化させて L P C VDにより 窒化珪素膜を形成したが、 バンドギャップは 4. 9 e V〜 5 e Vの 範囲内にとどまり、 L P C V Dではバンドギャップの制御は困難で あった （結果は図示を省略した） 。 As shown in Fig. 5, using a plasma C VD device 100, N 2 gas as nitrogen-containing gas, Si 2 H 6 gas as silicon-containing compound gas, and Ar gas as inert gas are used. Set the processing pressure to 2.7 Pa (2 0 mT orr) or 6 6.7 Pa (5 0 0 mT orr) and set the Si 2 H 6 / N 2 flow ratio from 0.0 1 By changing within the range of 0.04, the band gap of the formed silicon nitride film changed within the range of about 4, 8 eV to 6. OeV. In other words, by changing the Si 2 H 6 / N 2 flow rate ratio while keeping the processing pressure constant, the ratio of Si ZN contained in the silicon nitride film is controlled to easily perform nitriding having a desired band gap. A silicon film can be formed. In addition, from the results shown in Fig. 5, even if the same S HeZNs flow ratio (for example, Si 2 H 6 ZN 2 flow ratio is 0.0 1 or 0.0 4), the band gap is increased by changing the pressure. It can be seen that the thickness can be adjusted. For comparison, the silicon nitride film was formed by LPC VD with the process pressure changed in the same way, but the band gap remained in the range of 4.9 eV to 5 eV. It was difficult (results omitted).
( 0 0 5 9 )  (0 0 5 9)
以上のように、 プラズマ C VD装置 1 0 0を用いるプラズマ C V D処理において、 成膜されるバンドギャップの大きさを決定する主 な要因はシリコン含有化合物ガス 窒素ガス流量比であることが判 明した。 従って、 プラズマ C VD装置 1 0 0 を用いて、 他の条件は —定にし、 シリコン含有化合物ガス/窒素ガス流量比のみを変化さ せることにより、 膜中に含まれる S i ZNの比をコントロールして 相対的にバンドギヤップの大きな窒化珪素膜と、 小さな窒化珪素膜 を容易に形成できることが確認された。 As described above, in the plasma CVD process using the plasma CVD apparatus 100, it was found that the main factor that determines the size of the band gap to be formed is the silicon-containing compound gas nitrogen gas flow rate ratio. . Therefore, using the plasma C VD apparatus 1 0 0, the other conditions are -constant and only the silicon-containing compound gas / nitrogen gas flow ratio is changed. As a result, it was confirmed that a silicon nitride film having a relatively large bandgap and a small silicon nitride film can be easily formed by controlling the ratio of Si ZN contained in the film.
( 0 0 6 0 )  (0 0 6 0)
ノ ンドギャップの大きさが 2. 5 e V以上 7 e V以下の範囲内の 窒化珪素膜を形成するには、 処理圧力を 0. l P a以上 4 P a以下 の範囲内または 4 0 P a以上 1 3 3 3 P a以下の範囲内に設定し、 シリコン含有化合物ガス/窒素ガス流量比を 0. 0 0 5以上 0. 2 以下の範囲内から選択することが好ましく、 0. 0 0 5〜 0. 1以 下の範囲内から選択することがより好ましい。 また、 A rガスの流 量は 0 (供給せず） 〜： L O O O mLZm i n ( s c c m) の範囲内 、 好ましくは 5 0〜 8 0 0 mLZm i n ( s c c m) の範囲内、 N 2ガスの流量は 1 0 0〜 8 0 0 m L / i n ( s c c m) の範囲内 、 好ましくは 1 0 0〜 4 0 0 mL/m i n ( s c c m) の範囲内、 S i 2H6ガスの流量を ：！〜 4 0 0 mL /m i n ( s c c m) の範囲 内、 好ましくは 3〜 3 0 mL m i n ( s c c m) の範囲内から、 それぞれ上記流量比になるように設定することができる。 To form a silicon nitride film with a node gap size in the range of 2.5 eV to 7 eV, the processing pressure is in the range of 0. l Pa to 4 Pa, or 40 P. It is preferable to set the flow rate within a range from a to 1 3 3 3 Pa, and the silicon-containing compound gas / nitrogen gas flow ratio is preferably selected from the range from 0.0 0 5 to 0.2. It is more preferable to select from the range of 5 to 0.1 or less. The flow rate of Ar gas is 0 (not supplied) to: LOOO mLZm in (sccm), preferably within the range of 50 to 800 mLZm in (sccm), and the flow rate of N 2 gas is The flow rate of Si 2 H 6 gas is in the range of 10 0 to 80 0 mL / in (sccm), preferably in the range of 100 to 400 mL / min (sccm):! The flow rate ratio can be set within the range of ˜400 mL / min (sccm), preferably within the range of 3 to 30 mL min (sccm).
( 0 0 6 1 )  (0 0 6 1)
また、 プラズマ C VD処理の処理温度は、 載置台 2の温度を 3 0 0 °C以上、 好ましくは 4 0 0 以上 6 0 0 °C以下の範囲内に設定す る。  The processing temperature of the plasma C VD processing is set so that the temperature of the mounting table 2 is not less than 300 ° C., preferably not less than 4 00 ° C. and not more than 60 ° C.
( 0 0 6 2 )  (0 0 6 2)
また、 プラズマ C V D処理におけるマイクロ波のパワー密度は、 透過板の面積あたり 0. 2 5 6 WZ c m2以上 2. 0 4 5 W/ c m2 以下の範囲内とすることが好ましい。 Further, the microwave power density in the plasma CVD process is preferably in the range of 0.256 6 WZ cm 2 or more and 2.045 5 W / cm 2 or less per area of the transmission plate.
( 0 0 6 3 )  (0 0 6 3)
以上のように、 本発明の窒化珪素膜の製造方法では、 シリコン含 有化合物ガスと窒素ガスとを含む成膜ガスを用い、 シリコン含有化 合物ガス 窒素ガス流量比と処理圧力を選択してプラズマ C VDを 行なう ことにより、 膜中に含まれる S i ZNの比をコントロールし てウェハ W上に、 様々な大きさのバンドギャップの窒化珪素膜を簡 単に製造できる。 As described above, in the method for producing a silicon nitride film of the present invention, silicon-containing film is used. By using a deposition gas containing a compound gas and a nitrogen gas, a silicon-containing compound gas, selecting the nitrogen gas flow rate ratio and the processing pressure, and performing plasma C VD, the ratio of Si ZN contained in the film By controlling the above, it is possible to easily manufacture silicon nitride films of various sizes on the wafer W.
( 0 0 6 4 )  (0 0 6 4)
[第 2の実施の形態]  [Second Embodiment]
次に、 本発明の第 2の実施の形態に係る窒化珪素膜積層体の製造 方法について説明する。 前記第 1の実施の形態で説明したとおり、 プラズマ C VD装置 1 0 0においては、 窒化珪素膜を成膜する際の プラズマ C V D処理の条件、 特にシリコン含有化合物ガスノ窒素ガ ス流量比を選定することにより、 膜中に含まれる S i /Nの比をコ ン卜ロールして形成される窒化珪素膜のバンドギャップを所望の大 きさにコントロールできる。 従って、 例えば隣接する窒化珪素膜の バンドギャップの大きさが異なる複数の窒化珪素膜からなる窒化珪 素膜積層体を容易に製造することができる。  Next, a method for manufacturing a silicon nitride film laminate according to the second embodiment of the present invention will be described. As described in the first embodiment, in the plasma C VD apparatus 100, the conditions of the plasma CVD process when forming the silicon nitride film, particularly the silicon-containing compound gas nitrogen gas flow rate ratio are selected. As a result, the band gap of the silicon nitride film formed by controlling the ratio of Si / N contained in the film can be controlled to a desired size. Therefore, for example, a silicon nitride film laminate composed of a plurality of silicon nitride films having different band gap sizes between adjacent silicon nitride films can be easily manufactured.
( 0 0 6 5 )  (0 0 6 5)
図 6 A〜図 6 Fは、 プラズマ C VD装置 1 0 0において行われる 窒化珪素膜積層体の製造工程を示した工程図である。 まず、 図 6 A に示したように、 任意の下地層 （例えば二酸化珪素膜） 6 0の上に 、 S i 2H6/N2プラズマを用いて第 1の流量比 （ S i 2H6/N2流 量比） でプラズマ C VD処理を行い、 図 6 Bに示したように、 第 1 のバンドギャップを有する第 1 の窒化珪素膜 7 0を形成する。 次に 、 図 6 Cに示したように、 第 1 の窒化珪素膜 7 0の上に、 S i 2H6 /N2プラズマを用いて第 2の流量比 （ S i 2H6/N2流量比） でプ ラズマ C V D処理を行い、 図 6 Dに示したように、 第 2のバンドギ ヤップを有する第 2の窒化珪素膜 7 1 を形成する。 これにより、 2 9057006 層の窒化珪素膜からなる窒化珪素膜積層体 8 0を形成できる。 さら に必要に応じて、 図 6 Eに示したように、 第 2の窒化珪素膜 7 1 の 上に、 S i 2 H6 /N2プラズマを用いて、 第 3の流量比 （ S i 2 H6 /N2流量比） でプラズマ C VD処理を行い、 図 6 Fに示したよう に、 第 3のバンドギャップを有する第 3の窒化珪素膜 7 2を形成す ることもできる。 以降、 プラズマ C VD処理を必要回数繰り返し行 うことによって、 所望の層構造を有する窒化珪素膜積層体 8 0 を形 成できる。 FIG. 6A to FIG. 6F are process diagrams showing a manufacturing process of the silicon nitride film laminate performed in the plasma C VD apparatus 100. First, as shown in FIG. 6A, a first flow rate ratio (S i 2 H 6) using Si 2 H 6 / N 2 plasma on an arbitrary underlayer (eg, silicon dioxide film) 60. A plasma C VD process is performed at a / N 2 flow rate ratio, and as shown in FIG. 6B, a first silicon nitride film 70 having a first band gap is formed. Next, as shown in FIG. 6C, a second flow rate ratio (S i 2 H 6 / N 2) is formed on the first silicon nitride film 70 using Si 2 H 6 / N 2 plasma. A plasma CVD process is performed at a flow rate ratio to form a second silicon nitride film 71 having a second band gap, as shown in FIG. 6D. This will give you 2 9057006 A silicon nitride film laminate 80 composed of a silicon nitride film can be formed. Further, if necessary, as shown in FIG. 6E, a third flow ratio (S i 2) is used by using Si 2 H 6 / N 2 plasma on the second silicon nitride film 7 1. It is also possible to perform plasma CVD treatment at a H 6 / N 2 flow ratio) to form a third silicon nitride film 72 having a third band gap as shown in FIG. 6F. Thereafter, the silicon nitride film laminate 80 having a desired layer structure can be formed by repeating the plasma C VD treatment as many times as necessary.
( 0 0 6 6 )  (0 0 6 6)
本発明の窒化珪素膜積層体の製造方法では、 シリコン含有化合物 ガスと窒素ガスとを含む成膜ガスを用い、 シリコン含有化合物ガス /窒素ガス流量比を 0. 0 0 5以上 0. 2以下の範囲内から選択し 、 0. l P a以上 4 P a以下の範囲内または 4 0 P a以上 1 3 3 3 P a以下の範囲内で処理圧力を一定に設定してプラズマ C VDを行 なう ことにより、 膜中に含まれる S i /Nの比をコントロールして 例えば 2. 5 e V〜 7 e Vの範囲内で窒化珪素膜のバンドギャップ を変化させることができる。 すなわち、 処理圧力を 0. l P a以上 4 P a以下の範囲内または 4 0 P a以上 1 3 3 3 P a以下の範囲内 で一定にして、 上記第 1の流量比、 第 2の流量比および第 3の流量 比を 0. 0 0 5以上 0. 2以下の範囲内で変化させることにより、 膜中に含まれる S i ZNの比をコントロールして第 1の窒化珪素膜 7 0、 第 2の窒化珪素膜 7 1および第 3の窒化珪素膜 7 2のバンド ギャップの大きさを 2. 5 e V〜 7 e Vの範囲内で制御できる。  In the method for producing a silicon nitride film laminate of the present invention, a film-forming gas containing a silicon-containing compound gas and a nitrogen gas is used, and the silicon-containing compound gas / nitrogen gas flow rate ratio is not less than 0.05 and not more than 0.2. Select from the range, and perform plasma C VD by setting the processing pressure constant within the range of 0. l Pa to 4 Pa, or within the range of 40 Pa to 1 3 3 3 Pa. Thus, the band gap of the silicon nitride film can be changed within the range of 2.5 eV to 7 eV by controlling the ratio of Si / N contained in the film. That is, the processing pressure is kept constant within the range of 0. 1 Pa to 4 Pa, or within the range of 40 Pa to 1 3 3 3 Pa. The first silicon nitride film 70, by controlling the ratio of Si ZN contained in the film by changing the ratio and the third flow rate ratio within the range of 0.005 to 0.2. The band gap sizes of the second silicon nitride film 71 and the third silicon nitride film 72 can be controlled within the range of 2.5 eV to 7 eV.
( 0 0 6 7 )  (0 0 6 7)
例えば、 処理圧力を 0. 1 P a以上 4 P a以下の範囲内で一定に 設定し、 シリコン含有化合物ガス/窒素ガス流量比を 0. 0 0 5以 上 0. 2以下の範囲内から、 第 1の流量比く第 2の流量比 <第 3の T/JP2009/057006 流量比となるように選択すれば、 バンドギャップの大きさが、 第 1 の窒化珪素膜 7 0〉第 2の窒化珪素膜 7 1 >第 3の窒化珪素膜 7 2 であるエネルギーバンド構造を有する窒化珪素膜積層体 8 0を形成 できる。 また、 処理圧力を 4 0 P a以上 1 3 3 3 P a以下の範囲内 の範囲内で一定に設定し、 シリコン含有化合物ガスノ窒素ガス流量 比を 0. 0 0 5以上 0. 2以下の範囲内から、 第 1の流量比 <第 2 の流量比 <第 3の流量比となるように選択すれば、 バンドギャップ の大きさが、 第 1 の窒化珪素膜 7 0ぐ第 2の窒化珪素膜 7 1ぐ第 3 の窒化珪素膜 7 2であるエネルギーバンド構造を有する窒化珪素膜 積層体 8 0 を形成できる。 なお、 例えば第 1の流量比と第 3の流量 比を同じに設定することで、 第 1の窒化珪素膜 7 0 =第 3の窒化珪 素膜 7 2 となるエネルギーバンドギャップ構造を作ることも可能で ある。 For example, the processing pressure is set constant within the range of 0.1 Pa or more and 4 Pa or less, and the silicon-containing compound gas / nitrogen gas flow rate ratio is set within the range of 0.005 to 0.2 and below. 1st flow ratio 2nd flow ratio <3rd T / JP2009 / 057006 If the flow ratio is selected, the size of the band gap is as follows: first silicon nitride film 70> second silicon nitride film 7 1> third silicon nitride film 7 2 A silicon nitride film laminate 80 having an energy band structure can be formed. Also, the processing pressure is set constant within the range of 40 Pa to 1 3 3 3 Pa, and the silicon-containing compound gas nitrogen gas flow ratio is in the range of 0.0 0 5 to 0.2. If the first flow rate ratio <the second flow rate ratio <the third flow rate ratio is selected, the band gap is larger than the first silicon nitride film 70 by the second silicon nitride film. A silicon nitride film laminate 80 having an energy band structure, which is a third silicon nitride film 72, can be formed. For example, by setting the first flow rate ratio and the third flow rate ratio to be the same, an energy band gap structure in which the first silicon nitride film 70 = the third silicon nitride film 72 can be formed. It is possible.
( 0 0 6 8 )  (0 0 6 8)
ここで、 バンドギャップの大きさが例えば 2. 5 e V以上 5 e V 以下の範囲内の窒化珪素膜を形成するには、 処理圧力を 0. l P a 以上 4 P a以下の範囲内に設定し、 シリコン含有化合物ガス Z窒素 ガス流量比を 0. 0 4以上 0. 2以下の範囲内から選択するか、 あ るいは、 処理圧力を 4 0 P a以上 1 3 3 3 P a以下の範囲内に設定 し、 シリコン含有化合物ガス/窒素ガス流量比を 0. 0 0 5以上 0 . 0 1以下の範囲内から選択することが好ましい。 このとき、 A r ガスの流量は 0〜 1 0 0 0 mL/m i n ( s c c m) の範囲内、 好 ましくは 5 0〜 8 0 01111^ / 111 1 11 ( s c c m) の範囲内、 N2ガ スの流量は 1 0 0〜 8 0 0 111 //111 1 11 ( s c c m) の範囲内、 好 ましくは 1 0 0〜 4 0 0 mL/m i n ( s c c m) の範囲内、 S i 2 H6ガスの流量は 1〜 4 0 mL /m i n ( s c c m) の範囲内、 好 ましくは 2〜 2 0 mLZm i n ( s c c m) の範囲内から、 それぞ T/JP2009/057006 れ上記流量比になるように設定することができる。 Here, in order to form a silicon nitride film whose band gap is in the range of, for example, 2.5 eV or more and 5 eV or less, the processing pressure is set in the range of 0.1 to 4 Pa. Set the silicon-containing compound gas Z nitrogen gas flow rate ratio within the range of 0.04 or more and 0.2 or less, or set the processing pressure to 40 Pa or more and 1 3 3 3 Pa or less. It is preferable that the silicon-containing compound gas / nitrogen gas flow rate ratio is set within the range, and is selected from the range of 0.005 or more and 0.01 or less. At this time, the flow rate of Ar gas is in the range of 0 to 100 mL / min (sccm), preferably in the range of 5 0 to 8 0 01111 ^ / 111 1 11 (sccm), N 2 gas The flow rate of the gas is in the range of 1 0 0 to 8 0 0 111 / / 111 1 11 (sccm), preferably in the range of 1 0 0 to 4 0 0 mL / min (sccm), S i 2 H 6 The gas flow rate is in the range of 1 to 40 mL / min (sccm), preferably in the range of 2 to 20 mLZm in (sccm). T / JP2009 / 057006 can be set to achieve the above flow ratio.
( 0 0 6 9 )  (0 0 6 9)
また、 バンドギャップの大きさが例えば 5 e V超 7 e V以下の範 囲内の窒化珪素膜を形成するには、 処理圧力を 0. l P a以上 4 P a以下の範囲内に設定し、 シリコン含有化合物ガス Z窒素ガス流量 比を 0. 0 0 5以上 0. 2以下の範囲内から選択するか、 あるいは 、 処理圧力を 4 0 P a以上 1 3 3 3 P a以下の範囲内で一定に設定 し、 シリコン含有化合物ガス 窒素ガス流量比を 0 . 0 1超 0. 2 以下の範囲内から選択することが好ましい のとき、 A rガスの 流量は 0 L 0 0 0 m L /m i n 、 s c c m) の範囲内、 好ましく は 5 0 8 0 0 mL/m i n ( s c c m ) の範囲内 N 2ガスの流 量は 1 0 0 8 0 O mL/m i n ( s c C m) の範囲内、 好ましく は 1 0 0 4 0 0 m L /m i n ( s e c m ) の範囲内、 S i 2 H 6ガ スの流量を l 4 0 mL//m i n ( s c c m) の範囲内、 好ましく は 2 ~ 2 0 m L /m i n ( s c c m) の範囲内から 、 それぞれ上記 流量比になるように設定する とができる In order to form a silicon nitride film whose band gap is in the range of, for example, more than 5 eV and not more than 7 eV, the processing pressure is set in the range of 0.1 l Pa to 4 Pa, Silicon-containing compound gas Z Nitrogen gas flow rate ratio is selected from the range of 0.05 or more and 0.2 or less, or the processing pressure is constant within the range of 40 Pa or more and 1 3 3 3 Pa or less When the silicon-containing compound gas nitrogen gas flow rate ratio is preferably selected from the range of more than 0.01 and less than 0.2, the Ar gas flow rate is 0 L 0 00 m L / min, sccm), preferably within 50 80 mL / min (sccm), N 2 gas flow rate within 10 00 800 mL / min (sc C m), preferably 1 Within the range of 0 0 4 0 0 m L / min (secm), the flow rate of Si 2 H 6 gas is within the range of l 4 0 mL / / min (sccm), preferably 2 to 20 m L / min Within the range of (sccm), the above flow rate ratio Can When the sea urchin set
( 0 0 7 0 )  (0 0 7 0)
上記いずれの場合も プラズマ C V D処理の処理温度は、 載置台 2の温度を 3 0 0 °C以上 、 好まし <は 4 0 0 °C以上 6 0 0 °C 以下の範囲内に設定する。  In any of the above cases, the processing temperature of the plasma C V D processing is set within the range of 300 ° C. or higher, preferably <400 ° C. or higher and 60 ° C. or lower, of the temperature of the mounting table 2.
( 0 0 7 1 )  (0 0 7 1)
また、 上記いずれの場合も プラズマ C V D処理におけるマイク 口波のパヮ一密度は、 透過板の面積あたり 0. 2 5 6 W/ c m2以 上 2. 0 4 5 W/ c m2以下の範囲内とすることが好ましい。 Further, the Pawa one density of the microphone port waves in even plasma CVD process in either case, the permeation area per 0. 2 5 6 W / cm 2 or more on the plate 2. the range of 0 4 5 W / cm 2 or less It is preferable to do.
( 0 0 7 2 )  (0 0 7 2)
本発明の窒化珪素膜積層体の製造方法では、 シリコン含有化合物 ガスと窒素ガスとを含む成膜ガスを用い、 シリコン含有化合物ガス P T/JP2009/057006 ノ窒素ガス流量比と処理圧力を選択してプラズマ C V Dを行なう こ とにより、 ウェハ W上に、 バンドギャップが異なる窒化珪素膜を交 互に堆積させて窒化珪素膜積層体を形成することができる。 特に、 本発明の窒化珪素膜積層体の製造方法では、 処理圧力を一定にして シリコン含有化合物ガス/窒素ガス流量比によって窒化珪素膜中に 含まれる S i / Nの比をコントロールしてバンドギャップの大小を 容易に制御できることから、 異なるバンドギャップを有する窒化珪 素膜の積層体を形成する場合に、 同一処理容器内で真空状態を維持 したまま連続的な成膜が可能になり、 プロセス効率を向上させる上 で極めて有利である。 In the method for producing a silicon nitride film laminate of the present invention, a silicon-containing compound gas is used, using a film-forming gas containing a silicon-containing compound gas and a nitrogen gas. PT / JP2009 / 057006 By selecting the nitrogen gas flow ratio and processing pressure and performing plasma CVD, silicon nitride films with different band gaps are alternately deposited on the wafer W to form a silicon nitride film stack. Can be formed. In particular, in the method for producing a silicon nitride film laminate of the present invention, the band gap is controlled by controlling the ratio of Si / N contained in the silicon nitride film according to the flow rate ratio of silicon-containing compound gas / nitrogen gas with a constant processing pressure. Therefore, when forming a stack of silicon nitride films having different band gaps, it is possible to continuously form films while maintaining a vacuum state in the same processing vessel, and process efficiency It is extremely advantageous in improving the quality.
( 0 0 7 3 )  (0 0 7 3)
また、 処理圧力を一定にしてシリコン含有化合物ガス/窒素ガス 流量比の調節のみによって膜中に含まれる S i / Nの比をコント口 ールすることにより窒化珪素膜のバンドギヤップが容易に調整可能 であることから、 様々なバンドギャップ構造の窒化珪素膜積層体を 簡単に製造できる。 そのため、 本発明方法を、 M O S型半導体メモ リ装置の電荷蓄積領域としての窒化珪素膜積層体の形成に適用する ことにより、 優れたデ一夕保持特性と、 高速のデータ書換え性能と 、 低消費電力での動作性能と、 高い信頼性と、 を同時に兼ね備えた M O S型半導体メモリ装置を製造できる。  In addition, the bandgap of the silicon nitride film can be easily adjusted by controlling the Si / N ratio contained in the film only by adjusting the flow rate ratio of the silicon-containing compound gas / nitrogen gas while keeping the processing pressure constant. Therefore, it is possible to easily manufacture silicon nitride film laminates having various band gap structures. Therefore, by applying the method of the present invention to the formation of a silicon nitride film stack as a charge storage region of a MOS type semiconductor memory device, excellent data retention characteristics, high-speed data rewriting performance, and low consumption It is possible to manufacture MOS-type semiconductor memory devices that have both power performance and high reliability.
( 0 0 7 4 )  (0 0 7 4)
[第 3の実施の形態]  [Third embodiment]
以下、 本発明の第 3の実施の形態について説明する。 上記第 1お よび第 2の実施の形態では、 プラズマ C V Dの処理圧力と成膜原料 ガスの流量比によって窒化珪素膜のバンドギヤップを変化させたが 、 本実施の形態では、 プラズマ C V Dの過程で被処理体であるゥェ ハ Wに高周波バイアス電圧を印加することによって、 窒化珪素膜の 7006 バンドギャップを更に容易に変化させることができる。 図 7は、 本 実施の形態に係る窒化珪素膜の製造方法に利用可能なプラズマ C V D装置 2 0 0の概略構成を模式的に示す断面図である。 以下の説明 では、 プラズマ C V D装置 1 0 0 との相違点を中心に説明し、 同一 の構成には同一の符号を付して説明を省略する。 Hereinafter, a third embodiment of the present invention will be described. In the first and second embodiments, the band gap of the silicon nitride film is changed according to the plasma CVD processing pressure and the flow rate ratio of the film forming raw material gas. However, in the present embodiment, in the process of the plasma CVD. By applying a high-frequency bias voltage to wafer W, the workpiece, the silicon nitride film 7006 The band gap can be changed more easily. FIG. 7 is a cross-sectional view schematically showing a schematic configuration of a plasma CVD apparatus 200 that can be used in the method of manufacturing a silicon nitride film according to the present embodiment. In the following description, differences from the plasma CVD apparatus 100 will be mainly described, and the same components will be denoted by the same reference numerals and description thereof will be omitted.
( 0 0 7 5 )  (0 0 7 5)
プラズマ C V D装置 2 0 0において、 載置台 2の表面側には電極 7が埋設されている。 この電極 7は、 ヒータ 5 と載置台 2の表面と の間に配置されている。 この電極 7に、 給電線 7 aによって、 マツ チングボックス （M . B . ) 8を介してバイアス用の高周波電源 9 が接続されている。 高周波電源 9より電極 7 に高周波電力を供給す ることによって、 基板であるウェハ Wに高周波バイアス電圧 （R F バイアス） を印加できる構成となっている。 電極 7の材質としては 、 載置台 2の材質である A 1 N等のセラミックスと同等の熱膨張係 数を有する材質が好ましく、 例えばモリブデン、 タングステンなど の導電性材料を用いることが好ましい。 電極 7は、 例えば網目状、 格子状、 渦巻き状等の形状に形成されている。 電極 7のサイズは、 少なく とも被処理体と同等かそれより大きく形成することが好まし い。  In the plasma C V D apparatus 200, an electrode 7 is embedded on the surface side of the mounting table 2. The electrode 7 is disposed between the heater 5 and the surface of the mounting table 2. A high frequency power supply 9 for bias is connected to the electrode 7 via a matching box (M.B.) 8 by a feeder line 7a. By supplying high-frequency power to the electrode 7 from the high-frequency power source 9, a high-frequency bias voltage (R F bias) can be applied to the wafer W, which is the substrate. The material of the electrode 7 is preferably a material having a thermal expansion coefficient equivalent to that of ceramics such as A 1 N which is the material of the mounting table 2, and for example, a conductive material such as molybdenum or tungsten is preferably used. The electrode 7 is formed in, for example, a mesh shape, a lattice shape, a spiral shape, or the like. The size of the electrode 7 is preferably at least equal to or larger than the object to be processed.
( 0 0 7 6 )  (0 0 7 6)
次に、 プラズマ C V D装置 2 0 0 を用いたプラズマ C V D法によ る窒化珪素膜の堆積処理について説明する。 まず、 ゲートバルブ 1 7 を開にして搬入出口 1 6からウェハ Wを処理容器 1内に搬入し、 載置台 2上に載置する。 次に、 処理容器 1内を減圧排気しながら、 ガス供給装置 1 8の窒素含有ガス供給源 1 9 a、 シリコン含有化合 物ガス供給源 1 9 bおよび不活性ガス供給源 1 9 cから、 窒素含有 ガス、 シリコン含有化合物ガスおよび不活性ガス （例えば A rガス JP2009/057006 Next, the silicon nitride film deposition process by the plasma CVD method using the plasma CVD apparatus 200 will be described. First, the gate valve 17 is opened, and the wafer W is loaded into the processing container 1 from the loading / unloading port 16 and mounted on the mounting table 2. Next, while exhausting the inside of the processing container 1 under reduced pressure, nitrogen is supplied from the nitrogen-containing gas supply source 19a, the silicon-containing compound gas supply source 19b and the inert gas supply source 19c of the gas supply device 18 Contained gas, silicon-containing compound gas and inert gas (eg Ar gas) JP2009 / 057006
) を所定の流量でそれぞれ第 1のガス導入孔 1 4及び第 2のガス導 入孔 1 5 を介して処理容器 1内に導入する。 そして、 処理容器 1内 を所定の圧力に調節する。 ) Are introduced into the processing vessel 1 through the first gas introduction hole 14 and the second gas introduction hole 15 at a predetermined flow rate, respectively. Then, the inside of the processing container 1 is adjusted to a predetermined pressure.
( 0 0 7 7 )  (0 0 7 7)
次に、 マイクロ波発生装置 3 9で発生させた所定周波数例えば 2 . 4 5 GH zのマイクロ波を、 マッチング回路 3 8を介して導波管 3 7に導く。 導波管 3 7に導かれたマイクロ波は、 矩形導波管 3 7 bおよび同軸導波管 3 7 aを順次通過し、 内導体 4 1 を介して平面 アンテナ板 3 1 に供給される。 つまり、 マイクロ波は、 同軸導波管 3 7 a内を平面アンテナ板 3 1 に向けて伝搬していく。 そして、 マ イク口波は、 平面アンテナ板 3 1のスロッ ト状のマイクロ波放射孔 3 2から透過板 2 8を介して処理容器 1内におけるウェハ Wの上方 空間に放射させられる。 この際のマイクロ波出力は、 マイクロ波が 透過する領域の透過板 2 8の面積あたりの出力密度として 0. 2 5 〜 2. 5 6 W/ c m2の範囲内とすることが好ましい。 マイクロ波 出力は、 例えば 5 0 0〜 5 0 0 0 Wの範囲内から目的に応じて上記 範囲内の出力密度になるように選択することができる。 Next, a microwave having a predetermined frequency, for example, 2.45 GHz, generated by the microwave generator 39 is guided to the waveguide 37 via the matching circuit 38. The microwave guided to the waveguide 3 7 sequentially passes through the rectangular waveguide 3 7 b and the coaxial waveguide 3 7 a and is supplied to the planar antenna plate 3 1 through the inner conductor 4 1. That is, the microwave propagates in the coaxial waveguide 3 7 a toward the planar antenna plate 3 1. Then, the microphone mouth wave is radiated from the slot-like microwave radiation hole 32 of the planar antenna plate 31 to the space above the wafer W in the processing chamber 1 through the transmission plate 28. The microwave output at this time is preferably in the range of 0.25 to 2.56 W / cm 2 as the output density per area of the transmission plate 28 in the region where the microwave is transmitted. The microwave output can be selected, for example, from the range of 500 to 500 W so that the output density is within the above range according to the purpose.
( 0 0 7 8 )  (0 0 7 8)
平面アンテナ 3 1から透過板 2 8 を経て処理容器 1 に放射された マイクロ波により、 処理容器 1内で電磁界が形成され、 A rガス、 窒素含有ガス、 シリコン含有化合物ガスがそれぞれプラズマ化する 。 そして、 プラズマ中で原料ガスの解離が効率的に進み、 イオンや ラジカルなどの活性種、 例えば S i PHい S i HQ、 NH 、 Nなど 、 の反応によって、 窒化珪素 S i Nの薄膜が堆積される。 An electromagnetic field is formed in the processing container 1 by the microwave radiated from the planar antenna 3 1 to the processing container 1 through the transmission plate 2 8, and Ar gas, nitrogen-containing gas, and silicon-containing compound gas are turned into plasma, respectively. . The dissociation of the source gas in the plasma processing proceeds efficiently, active species such as ions and radicals, e.g. S i P H There S i H Q, NH, by reactions such as N,, a thin film of silicon nitride S i N Is deposited.
( 0 0 7 9 )  (0 0 7 9)
また、 プラズマ C VD処理を行なっている間、 載置台 2の電極 7 に高周波電源 9から所定の周波数および大きさの高周波電力 （ R F 057006 バイアス） をウェハ Wに供給する。 プラズマ C V D装置 2 0 0では 、 プラズマの電子温度を低く維持できるので、 膜へのダメージがな く、 しかも、 高密度プラズマにより、 成膜ガスの分子が解離されや すいので、 反応が促進される。 また、 適切な範囲での R Fバイアス の印加は、 プラズマ中のイオンをウェハ Wへ引き込むように作用す るため、 成膜される窒化珪素膜の S i /Nの比をコントロールでき 、 バンドギャップを変化させるように作用する。 In addition, during the plasma C VD treatment, a high frequency power (RF) of a predetermined frequency and magnitude is applied to the electrode 7 of the mounting table 2 from the high frequency power source 9. 057006 Bias) to wafer W. In the plasma CVD apparatus 200, since the plasma electron temperature can be kept low, there is no damage to the film, and the molecules of the film forming gas are easily dissociated by the high-density plasma, thus promoting the reaction. . In addition, the application of RF bias in the appropriate range acts to attract ions in the plasma to the wafer W, so the Si / N ratio of the silicon nitride film to be formed can be controlled, and the band gap can be reduced. Acts to change.
( 0 0 8 0 )  (0 0 8 0)
本実施の形態において、 高周波電源 9から供給される R Fバイァ スの周波数は、 例えば 4 0 0 k H z以上 6 O MH z以下の範囲内が 好ましく、 4 5 0 k H z以上 2 O MH z以下の範囲内がより好まし い。 また、 本実施の形態において、 R Fバイアスは、 ウェハ Wの面 積当たりの出力密度として例えば 0. 0 1 Wノ c m2以上 0. 6 4 WZ c m2以下の範囲内で供給することが好ましく、 0. 0 3 2 W / c m2以上 0. 1 6 WZ c m2以下の範囲内で供給することがより 好ましい。 また、 本実施の形態において、 R Fバイアス出力は 1 W 以上 2 0 0 W以下の範囲内が好ましく、 より好ましくは 1 W以上 5 0 W以下の範囲内から、 上記出力密度になるように R Fバイアスを 供給することができる。 In the present embodiment, the frequency of the RF bias supplied from the high-frequency power supply 9 is preferably in the range of, for example, 4 00 kHz to 6 O MHz, and 4 500 kHz to 2 O MHz. The following range is more preferable. Further, in the present embodiment, the RF bias is preferably supplied within the range of, for example, 0.0 1 W cm 2 or more and 0.64 WZ cm 2 or less as the output density per wafer W area. It is more preferable to supply within the range of 0.0 3 2 W / cm 2 or more and 0.1 6 WZ cm 2 or less. In the present embodiment, the RF bias output is preferably in the range of 1 W or more and 20 0 W or less, more preferably in the range of 1 W or more and 50 0 W or less so that the RF bias is set to the above output density. Can be supplied.
( 0 0 8 1 )  (0 0 8 1)
以上の条件は、 制御部 5 0の記憶部 5 3にレシピとして保存され ている。 そして、 プロセスコントローラ 5 1がそのレシピを読み出 してプラズマ C VD装置 2 0 0の各構成部例えばガス供給装置 1 8 、 排気装置 2 4、 マイクロ波発生装置 3 9、 ヒータ電源 5 a、 高周 波電源 9などへ制御信号を送出することにより、 所望の条件でのプ ラズマ C VD処理が実現する。  The above conditions are stored as recipes in the storage unit 53 of the control unit 50. Then, the process controller 51 reads the recipe, and each component of the plasma C VD device 200, for example, the gas supply device 18, the exhaust device 24, the microwave generator 39, the heater power source 5 a, high By sending control signals to the frequency power supply 9 etc., plasma C VD processing under the desired conditions is realized.
( 0 0 8 2 ) また、 上記構成を有するプラズマ C VD装置 2 0 0においては、 窒化珪素膜を成膜する際に、 高周波電源 9から載置台 2の電極 7に 高周波電力を 0. 0 1 W/ c m2以上 0. 6 4 WZ c m2以下、 好ま しくは 0. 0 3 2 Ψ/ c m2以上 0. 1 6 W/ c m2以下の出力密度 の範囲内で供給することにより、 ウェハ Wに R Fバイアスを印加し て形成される窒化珪素膜の S i /Nの比をコントロールしてバンド ギャップをコントロールできる。 (0 0 8 2) Further, in the plasma C VD apparatus 200 having the above-described configuration, when a silicon nitride film is formed, high-frequency power is applied to the electrode 7 of the mounting table 2 from the high-frequency power source 9 to 0.0 1 W / cm 2 or more 6 4 WZ cm 2 or less, preferably 0. 0 3 2 Ψ / cm 2 or more 0.1. 6 W / cm 2 or less to supply RF bias to wafer W by supplying it within the range of power density. The band gap can be controlled by controlling the Si / N ratio of the silicon nitride film formed.
( 0 0 8 3 )  (0 0 8 3)
図 8 Aおよび図 8 Bは、 プラズマ C VD装置 2 0 0 において行わ れる窒化珪素膜の製造工程を示した工程図である。 図 8 Aに示した ように、 任意の下地層 （例えば、 S i 02膜） 6 0 ) の上に、 N2Z S i 2H6プラズマを用いてプラズマ C VD処理を行う。 このプラズ マ C VD処理では、 高周波電源 9から、 載置台 2の電極 7に 0. 0 l W/ c m2以上 0. 6 4 WZ c m 2の範囲内の出力密度で高周波電 力を供給して、 ウェハ Wに R Fバイアスが印加される。 これにより 、 図 8 Bに示したように、 S i /Nの比をコントロールした窒化珪 素膜 7 0を形成することができ、 窒化珪素膜 7 0のバンドギャップ を変化させることができる。 FIG. 8A and FIG. 8B are process diagrams showing the manufacturing process of the silicon nitride film performed in the plasma C VD apparatus 200. As shown in FIG. 8A, a plasma C VD process is performed using N 2 ZS i 2 H 6 plasma on an arbitrary underlayer (eg, S i 0 2 film) 6 0). In this plasma C VD treatment, high-frequency power is supplied from the high-frequency power source 9 to the electrode 7 of the mounting table 2 at a power density within a range of 0.0 l W / cm 2 or more and 0.64 WZ cm 2. RF bias is applied to wafer W. Thus, as shown in FIG. 8B, a silicon nitride film 70 with a controlled Si / N ratio can be formed, and the band gap of the silicon nitride film 70 can be changed.
( 0 0 8 4 )  (0 0 8 4)
下記の条件でプラズマ C VDを行い、 成膜時に供給する R Fバイ ァス出力と、 成膜される窒化珪素膜のバンドギャップの大きさとの 関係を評価する実験を行った。  Plasma C VD was performed under the following conditions, and an experiment was conducted to evaluate the relationship between the RF bias output supplied during film formation and the band gap size of the silicon nitride film to be formed.
( 0 0 8 5 )  (0 0 8 5)
[プラズマ C VD条件]  [Plasma C VD condition]
処理温度 （載置台） ： 4 0 0 °C  Processing temperature (mounting table): 4 0 0 ° C
マイクロ波パワー ： 2 kW (パワー密度 1. 5 3 W/ c m2 ； 透 過板面積あたり） 57006 処理圧力 ； 2. 7 P a , 2 6. 6 P aまたは 4 0 P a Microwave power: 2 kW (Power density 1.5 3 W / cm 2 ; Permeation area) 57006 Processing pressure: 2.7 Pa, 2 6. 6 Pa or 40 Pa
S i 2H6流量 ； 2 m L / m i n ( s c c m) S i 2 H 6 flow rate; 2 ml / min (sccm)
N2ガス流量 ； 4 0 0 m L /m i n ( s c c m) N 2 gas flow rate: 400 m L / min (sccm)
A rガス流量 ； 6 0 O mLZm i n ( s c c m)  A r Gas flow rate ： 60 O mLZm i n (s c c m)
R Fバイアス用高周波電力 ； 0 W (供給せず） ， 5 W， 1 0 W, R F Bias RF power: 0 W (not supplied), 5 W, 10 W,
5 0 W 5 0 W
( 0 0 8 6 )  (0 0 8 6)
実験の結果を図 9に示した。 処理圧力が 2. 7 P aまたは 2 6. The result of the experiment is shown in FIG. Processing pressure is 2.7 Pa or 2 6.
6 P aの場合には、 R Fバイアス用高周波電力を大きくするほど S i ZNの比が小さくなり、 窒素リ ッチな窒化珪素膜となって、 バン ドギャップが大きくなる傾向が見られた。 処理圧力が 4 0 P aでは 、 R Fバイアス用高周波電力密度が 0. 0 3 2 WZ c m2以上の範 囲でウェハ Wへの R Fバイアス用高周波電力を大きくするほど、 バ ンドギャップが大きくなることが判明した。 以上の結果から、 例え ばバンドギャップの大きさを 5〜 6 e Vの範囲内で制御するために は、 処理圧力を 0. l P a以上 1 3 3 3 P a以下、 好ましくは 1 P a以上 4 0 P a以下の範囲内で一定に設定し、 シリコン含有化合物 ガスと N2ガスとの流量比 （例えば S i 2H6流量/ N2流量） を 0.In the case of 6 Pa, the Si ZN ratio decreased as the RF bias RF power increased, and the band gap tended to increase as a nitrogen-rich silicon nitride film. When the processing pressure is 40 Pa, the band gap increases as the RF bias RF power to the wafer W is increased within the RF bias RF power density range of 0.0 3 2 WZ cm 2 or higher. There was found. From the above results, for example, in order to control the size of the band gap within the range of 5 to 6 eV, the treatment pressure is set to 0.1 l Pa or more and 1 3 3 3 Pa or less, preferably 1 Pa. The flow rate ratio between silicon-containing compound gas and N 2 gas (for example, Si 2 H 6 flow rate / N 2 flow rate) is set to 0.
0 0 5以上 0. 2以下の範囲内から選択して、 R Fバイアス用高周 波電力密度 0. O l W/ c m2以上 0. 6 4 WZ c m2以下の範囲内 で供給することが好ましく、 0. 0 3 2 W/ c m2以上 0. 1 6 W / c m2以下の範囲内で供給することがより好ましいことが示され た。 High frequency power density for RF bias selected from the range of 0 0 5 or more and 0.2 or less, and preferably supplied within the range of 0. Ol W / cm 2 or more and 0.64 WZ cm 2 or less. It was shown that it is more preferable to supply within the range of 0.0 3 2 W / cm 2 or more and 0.1 6 W / cm 2 or less.
( 0 0 8 7 )  (0 0 8 7)
次に、 処理圧力を一定にして、 R Fバイアス用高周波電力と A r 流量を変化させることにより、 成膜される窒化珪素膜のバンドギヤ ップにどのような影響を与えるかを調べた。 プラズマ C V Dの条件 は下記のとおりである。 Next, we investigated the effect of changing the RF bias RF power and Ar flow rate while keeping the processing pressure constant, which affects the bandgap of the silicon nitride film. Plasma CVD conditions Is as follows.
( 0 0 8 8 )  (0 0 8 8)
[プラズマ C V D条件]  [Plasma C V D condition]
処理温度 （載置台） ： 4 0 0 °C  Processing temperature (mounting table): 4 0 0 ° C
マイクロ波パワー ： 2 k W (パワー密度 1. 5 3 W/ c m2 ； 透 過板面積あたり） Microwave power: 2 kW (power density 1.5 3 W / cm 2 ; per plate area)
処理圧力 ； 2 6. 6 P a  Processing pressure; 2 6. 6 Pa
S i 2H6流量 ； 2 m L /m i n ( s c c m) S i 2 H 6 flow rate; 2 ml / min (sccm)
N2ガス流量 ； 4 0 O mLZm i n ( s c c m) N 2 gas flow rate: 40 O mLZm in (sccm)
A rガス流量 ； l O O mL/m i n ( s c c m) 、 6 0 0 m L / m i n ( s c c m) または l l O O mL/m i n ( s c c m)  Ar gas flow rate: l O O mL / m i n (s c c m), 60 m L / m i n (s c c m) or l l O O mL / m i n (s c c m)
R Fバイアス用高周波電力 ； 0 W (供給せず） ， 5 W, 1 0 W, 5 0 W  R High frequency power for bias: 0 W (not supplied), 5 W, 10 W, 50 W
( 0 0 8 9 )  (0 0 8 9)
実験の結果を図 1 0に示した。 実験の処理圧力 （ 2 6. 6 P a ) では、 どの A r流量でも、 R Fバイアス用高周波電力を大きくする ほど S i /Nの比が小さくなり窒素リ ツチな窒化珪素膜となって、 バンドギャップが大きくなる傾向が見られた。 しかし、 A r流量が 1 1 0 0 m L / m i n ( s c c m) では、 ノ ンドギャップの変化は 0. 2 e V幅に止まった。 一方、 A r流量が l O O mLZm i n ( s c c m) または e O O mLZm i n ( s c c m) では、 バンドギ ヤップの変化は約 0. 4 e V幅であり、 R Fバイアス印加による効 果が大きく得られることが確認できた。 このように、 本実施の形態 において、 バンドギャップの大きさをコントロールし易くする観点 から、 R Fバイアスを印加する場合の A rガスの流量は 0 (供給せ ず） l O O O mL/m i n ( s c c m) の範囲内が好ましく、 1 0 0〜 6 0 O mL/m i n ( s c c m) の範囲内がより好ましいこ とが確認できた。 The results of the experiment are shown in FIG. At the experimental processing pressure (26.6 Pa), at any Ar flow rate, the higher the RF bias RF power, the smaller the S i / N ratio, resulting in a nitrogen-rich silicon nitride film. There was a tendency to increase the gap. However, when the Ar flow rate was 1 1 00 m L / min (sccm), the change in the node gap remained at 0.2 e V width. On the other hand, when the Ar flow rate is l OO mLZm in (sccm) or e OO mLZm in (sccm), the band gap change is about 0.4 eV, and the effect of RF bias application can be greatly obtained. It could be confirmed. Thus, in the present embodiment, from the viewpoint of easily controlling the size of the band gap, the flow rate of Ar gas when applying the RF bias is 0 (not supplied) l OOO mL / min (sccm) Preferably within the range of 100 to 60 O mL / min (sccm). I was able to confirm.
( 0 0 9 0 )  (0 0 9 0)
以上、 第 3の実施の形態における他の構成および効果は、 第 1の 実施の形態と同様である。 また、 上記第 2の実施の形態において、 第 1〜第 3の流量比 （ S i 2H6/N2流量比） を変化させる代わり に、 第 3の実施の形態で示したようにウェハ Wへの R Fバイアスの 大きさを変化させて窒化珪素膜積層体を製造することも可能である As described above, the other configurations and effects of the third embodiment are the same as those of the first embodiment. Further, in the second embodiment, instead of changing the first to third flow ratios (Si 2 H 6 / N 2 flow ratio), the wafer W as shown in the third embodiment is used. It is also possible to manufacture silicon nitride film stacks by changing the magnitude of the RF bias to
( 0 0 9 1 ) (0 0 9 1)
[第 4の実施の形態]  [Fourth embodiment]
図 1 1 Aおよび 1 1 Bは、 本発明の第 4の実施の形態に係る窒化 珪素膜の製造方法を説明するための図であり、 プラズマ C VD装置 1 0 0において行われる窒化珪素膜の製造工程を示した工程図であ る。 本実施の形態では、 窒素含有ガスとしてアンモニアガス （NH 3ガス） を用いている。 図 1 1 Aに示したように、 任意の下地層 （ 例えば二酸化珪素膜） 6 O Aの上に、 S i 2H6ZNH3プラズマを 用いて処理圧力でプラズマ C VD処理を行う。 ここでは、 シリコン 含有化合物ガスとアンモニアガスとを含む成膜ガスを用い、 シリコ ン含有化合物ガス/アンモニアガス流量比を 0. 0 1 5以上 0. 2 以下の範囲内に設定し、 0. 1 P a以上 1 3 3 3 P a以下の範囲内 から処理圧力を選択してプラズマ C VD処理を行う。 これにより、 図 1 1 Bに示したように、 2. 5 e V以上 7 e V以下の範囲内の大 きさのパンドギャップを有する窒化珪素膜 7 O Aを形成することが できる。 FIGS. 11A and 11B are views for explaining a method of manufacturing a silicon nitride film according to the fourth embodiment of the present invention. The silicon nitride film formed in the plasma C VD apparatus 100 is shown in FIGS. It is a process diagram showing a manufacturing process. In the present embodiment, ammonia gas (NH 3 gas) is used as the nitrogen-containing gas. As shown in Fig. 1 1 A, plasma C VD treatment is performed on an arbitrary underlayer (eg, silicon dioxide film) 6 OA at a treatment pressure using Si 2 H 6 ZNH 3 plasma. Here, a deposition gas containing silicon-containing compound gas and ammonia gas is used, and the flow rate ratio of silicon-containing compound gas / ammonia gas is set within the range of 0.015 to 0.2, and 0.1 Plasma C VD treatment is performed by selecting a treatment pressure from the range of Pa to 1 3 3 3 Pa. As a result, as shown in FIG. 11B, a silicon nitride film 7OA having a large gap in the range of 2.5 eV to 7 eV can be formed.
( 0 0 9 2 )  (0 0 9 2)
本発明の窒化珪素膜の製造方法では、 0. 1 3以上 1 3 3 3 a以下の範囲内で処理圧力を高くするほど、 形成される窒化珪素膜 P T/JP2009/057006 のバンドギャップが大きくなる傾向がある。 このため、 処理圧力を 上記 0. l P a以上 1 3 3 3 P a以下の範囲内で選択することによ り、 窒化珪素膜 7 O Aのバンドギャップの大きさを 2. 5 e V〜 7 e Vの範囲内で制御できる。 In the method for producing a silicon nitride film of the present invention, the higher the processing pressure is in the range of 0.13 to 1 3 3 3 a, the more the silicon nitride film that is formed The band gap of PT / JP2009 / 057006 tends to increase. Therefore, by selecting the processing pressure within the range of 0.1 l Pa to 1 3 3 3 Pa above, the band gap size of the silicon nitride film 7 OA is set to 2.5 eV to 7 Can be controlled within the eV range.
( 0 0 9 3 )  (0 0 9 3)
次に、 本発明の基礎となった実験データについて説明する。 図 1 2は、 窒素含有ガスとして N H 3ガス、 シリコン含有化合物ガスと して S i 2H6ガスを使用し、 プラズマ C VD装置 1 0 0 においてプ ラズマ C VDを実施し、 単膜の窒化珪素膜を形成した場合の窒化珪 素膜のバンドギャップと処理圧力との関係を示している。 プラズマ C VD条件は以下のとおりである。 Next, experimental data on which the present invention is based will be described. Fig. 12 shows the nitriding of a single film using NH 3 gas as the nitrogen-containing gas and Si 2 H 6 gas as the silicon-containing compound gas, and performing plasma C VD in the plasma C VD device 100. The relationship between the band gap of the silicon nitride film and the processing pressure when the silicon film is formed is shown. The plasma C VD conditions are as follows.
( 0 0 9 4 )  (0 0 9 4)
[プラズマ C V D条件]  [Plasma C V D condition]
処理温度 （載置台） ： 5 0 0 °C  Processing temperature (mounting table): 5 0 0 ° C
マイクロ波パワー ： 2 kW (パワー密度 1. 0 2 3 W/ c m2 ； 透過板面積あたり） Microwave power: 2 kW (Power density 1.0 2 3 W / cm 2 ; per transmission plate area)
処理圧力 ； 1 3. 3 P a ( 1 0 0 mT o r r ) 、 6 6. 7 P a ( 5 0 0 mT o r r ) 、  Processing pressure: 13.3 Pa (100 mTorr), 66.7 Pa (500 mTorr),
1 2 6 P a ( 9 5 0 mT o r r ) および 2 0 0 P a ( 1 5 0 0 m T o r r ) 、  1 2 6 Pa (9 5 0 m To r r) and 2 0 0 Pa (1 5 0 0 m To r r),
A rガス流量 ； 2 0 0 mLZm i n ( s c c m)  Ar gas flow rate; 20 0 mLZm i n (s c c m)
NH3ガス流量 ； 2 0 0 mLZm i n ( s c c m) NH 3 gas flow rate; 2 0 0 mLZm in (sccm)
S i 2H6ガス流量 ； 4 m L /m i n ( s c c m) または 8 mLZ m ί n ( s e c m) S i 2 H 6 gas flow rate; 4 mL / min (sccm) or 8 mLZ m ί n (secm)
( 0 0 9 5 )  (0 0 9 5)
なお、 窒化珪素膜のバンドギャップは、 薄膜特性測定装置 n & k • A n a 1 y z e r (商品名 ； n & kテクノロジー社製） を用いて 計測した。 The band gap of the silicon nitride film is measured using a thin film property measuring device n & k • A na 1 yzer (trade name; manufactured by n & k Technology). Measured.
( 0 0 9 6 )  (0 0 9 6)
図 1 2に示したように、 プラズマ C VD装置 1 0 0 を用い、 窒素 含有ガスとして NH3ガス、 シリコン含有化合物ガスとして S i 2 H 6ガス、 不活性ガスとして A rガスを使用し、 処理圧力を 1 3. 3 P a〜 1 3 3. 3 P aの範囲内で変化させた結果、 成膜される窒化 珪素膜のバンドギャップが約 5. 1 e Vから 5. 8 e Vの範囲内で 変化した。 この場合、 S i 2H6流量を一定にして処理圧力のみを変 化させることによって、 容易に所望のバンドギャップを有する窒化 珪素膜を形成することができる。 また、 処理圧力を主として制御し 、 必要に応じて S i 2H6流量を従として制御することも好ましい。 上記範囲の大きさのバンドギャップを形成するための原料ガスの流 量は以下の通りである。 S i 2H6流量は、 3 mL/m i n ( s e c m) 以上 4 0 mL/m i n ( s c c m) 以下の範囲内が好ましく、 3 m L Xm i n ( s c c m) ¾± 2 O mL/m i n ( s c c m) 以 下の範囲内がより好ましい。 NH3流量は、 5 0 mL/m i n ( s c c m) 以上 l O O O mL/m i n ( s c c m) 以下の範囲内が好 ましく、 5 0 m L /m i n ( s c c m) 以上 5 0 0 mL/m i n ( s c c m) 以下の範囲内がより好ましい。 さらに、 S i 2H6ガスと NH3ガスとの流量比 （ S i 2H6/NH3比） は、 0. 0 1 5以上 0 . 2以下の範囲内が好ましく、 0. 0 1 5〜 0. 1以下の範囲内が より好ましい。 なお、 比較のため、 同様に処理圧力を変化させて L P C V Dにより窒化珪素膜を形成したが、 ノ ンドギャップは 4. 9 e V〜 5 e Vの範囲内にとどまり、 L P C V Dではバンドギャップ の制御は困難であった （結果は図示を省略した） 。 As shown in Fig. 12, using plasma C VD apparatus 100, using NH 3 gas as nitrogen-containing gas, Si 2 H 6 gas as silicon-containing compound gas, and Ar gas as inert gas, As a result of changing the processing pressure within the range of 1 3.3 Pa to 1 3 3.3 Pa, the band gap of the silicon nitride film to be formed is about 5.1 eV to 5.8 eV. Changed within range. In this case, a silicon nitride film having a desired band gap can be easily formed by changing only the processing pressure while keeping the Si 2 H 6 flow rate constant. It is also preferable to mainly control the processing pressure and, if necessary, control the Si 2 H 6 flow rate as a slave. The flow rate of the source gas for forming the band gap in the above range is as follows. The Si 2 H 6 flow rate is preferably in the range of 3 mL / min (secm) to 40 mL / min (sccm), and is 3 mL / min (sccm) ¾ ± 2 O mL / min (sccm) or less. The lower range is more preferable. NH 3 flow rate is preferably in the range of 50 mL / min (sccm) or more to lOO mL / min (sccm) or less, more than 50 mL / min (sccm) to 50 mL / min (sccm) The following range is more preferable. Furthermore, the flow rate ratio between the Si 2 H 6 gas and the NH 3 gas (S i 2 H 6 / NH 3 ratio) is preferably in the range of 0.0 1 5 or more and 0.2 or less, and 0.0 1 5 Within the range of ˜0.1 or less is more preferable. For comparison, a silicon nitride film was formed by LPCVD with the process pressure varied in the same way, but the node gap remained within the range of 4.9 eV to 5 eV, and the bandgap was controlled by LPCVD. It was difficult (results omitted).
( 0 0 9 7 )  (0 0 9 7)
以上のように、 プラズマ C VD装置 1 0 0 を用いるプラズマ C V D処理において、 成膜されるバンドギャップの大きさを決定する主 な要因は処理圧力であることが判明した。 従って、 プラズマ C VD 装置 1 0 0を用いて、 他の条件は一定にし、 処理圧力のみを変化さ せることによりバンドギャップの大きさを制御して、 相対的にバン ドギャップの大きな窒化珪素膜と、 小さな窒化珪素膜を容易に形成 できることが確認された。 As described above, the plasma CV using the plasma C VD device 1 0 0 In the D process, it was found that the main factor that determines the size of the band gap to be deposited is the processing pressure. Therefore, by using the plasma C VD apparatus 100, other conditions are kept constant, and the size of the band gap is controlled by changing only the processing pressure, so that a silicon nitride film having a relatively large band gap can be obtained. It was confirmed that a small silicon nitride film can be easily formed.
( 0 0 9 8 )  (0 0 9 8)
バンドギャップの大きさが 2. 5 e V以上 7 e V以下の範囲内の 窒化珪素膜を形成するには、 シリコン含有化合物ガス （例えば S i 2H6ガス） とアンモニアガスとの流量比 （シリコン含有化合物ガス /アンモニアガス流量比） を 0. 0 1 5以上 0. 2以下の範囲内に 設定し、 処理圧力を 0. 1 P a以上 1 3 3 3 P a以下に設定するこ とが好ましい。 また、 A rガスの流量は 0〜： L 0 0 0 m L Zm i nIn order to form a silicon nitride film with a band gap size of 2.5 eV or more and 7 eV or less, the flow ratio of silicon-containing compound gas (eg, Si 2 H 6 gas) to ammonia gas ( (Silicon-containing compound gas / ammonia gas flow ratio) can be set within the range of 0.0 1 5 or more and 0.2 or less, and the processing pressure can be set to 0.1 Pa or more and 1 3 3 3 Pa or less. preferable. The Ar gas flow rate is 0 to: L 0 0 0 m L Zm in
( s c c m) の範囲内、 好ましくは 5 0〜 8 0 0 mLZm i n ( s c c m) の範囲内、 1^1^3ガスの流量は 1 0 0〜 8 0 01111^ 111 1 n ( s c c m) の範囲内、 好ましくは 1 0 0〜 4 0 0 mL/m i nWithin the range of (sccm), preferably within the range of 50-800 mLZm in (sccm), 1 ^ 1 ^ 3 The gas flow rate is within the range of 1 0 0-8 0 01111 ^ 111 1 n (sccm) , Preferably 100-400 mL / min
( s c c m) の範囲内、 S i 2 H6ガスの流量は 1〜 4 0 0 mL /m i n ( s c c m) の範囲内、 好ましくは S S O mLZm i n ( s c c m) の範囲内から、 それぞれ上記流量比になるように設定する ことができる。 Within the range of (sccm), the flow rate of Si 2 H 6 gas is within the range of 1 to 400 mL / min (sccm), preferably within the range of SSO mLZm in (sccm), respectively, with the above flow ratio. Can be set as follows.
( 0 0 9 9 )  (0 0 9 9)
また、 プラズマ C VD処理の処理温度は、 載置台 2の温度を 3 0 0 °C以上、 好ましくは 4 0 0 °C以上 6 0 0 °C以下の範囲内に設定す る。  The processing temperature of the plasma C VD processing is set such that the temperature of the mounting table 2 is not less than 300 ° C., preferably not less than 400 ° C. and not more than 60 ° C.
( 0 1 0 0 )  (0 1 0 0)
また、 プラズマ C VD処理におけるマイクロ波のパワー密度は、 透過板の面積あたり 0. 2 5 6 W/ c m2以上 2. 0 4 5 W/ c m2 以下の範囲内とすることが好ましい。 In addition, the microwave power density in plasma C VD treatment is 0.2 5 6 W / cm 2 or more per transmission plate area 2.0 4 5 W / cm 2 It is preferable to be within the following range.
( 0 1 0 1 )  (0 1 0 1)
本発明の窒化珪素膜の製造方法では、 シリコン含有化合物ガスと アンモニアガスとを含む成膜ガスを用い、 シリコン含有化合物ガス In the method for producing a silicon nitride film of the present invention, a film-forming gas containing a silicon-containing compound gas and an ammonia gas is used.
Zアンモニアガス流量比を 0. 0 1 5以上 0. 2以下の範囲内に設 定し、 0. l P a以上 1 3 3 3 P a以下の範囲内から選択される処 理圧力でプラズマ C VDを行なうことにより、 ウェハ W上に、 様々 な大きさのバンドギヤップの窒化珪素膜を簡単に製造できる。 Z Ammonia gas flow ratio is set within the range of 0.0 1 5 or more and 0.2 or less, and plasma C is applied at a processing pressure selected from the range of 0. l Pa or more and 1 3 3 3 Pa or less. By performing VD, various sizes of bandgap silicon nitride films can be easily manufactured on the wafer W.
( 0 1 0 2 )  (0 1 0 2)
[第 5の実施の形態]  [Fifth embodiment]
次に、 本発明の第 5の実施の形態に係る窒化珪素膜積層体の製造 方法について説明する。 前記第 1〜第 4の実施の形態で説明したと おり、 プラズマ C VD装置 1 0 0においては、 窒化珪素膜を成膜す る際のプラズマ C VD処理の条件、 特に圧力条件を選定することに より、 形成される窒化珪素膜のバンドギャップを所望の大きさにコ ントロールできる。 従って、 例えば隣接する窒化珪素膜のバンドギ ヤップの大きさが異なる複数の窒化珪素膜からなる窒化珪素膜積層 体を容易に製造することができる。  Next, a method for manufacturing the silicon nitride film laminate according to the fifth embodiment of the present invention will be described. As described in the first to fourth embodiments, in the plasma C VD apparatus 100, the plasma C VD processing conditions, particularly the pressure conditions, when forming the silicon nitride film should be selected. Thus, the band gap of the formed silicon nitride film can be controlled to a desired size. Therefore, for example, a silicon nitride film laminate composed of a plurality of silicon nitride films having different band gaps between adjacent silicon nitride films can be easily manufactured.
( 0 1 0 3 )  (0 1 0 3)
図 1 3 A〜図 1 3 Fは、 プラズマ C VD装置 1 0 0において行わ れる窒化珪素膜積層体の製造工程を示した工程図である。 まず、 図 FIGS. 13A to 13 F are process diagrams showing a manufacturing process of the silicon nitride film laminate performed in the plasma C VD apparatus 100. First, figure
1 3 Aに示したように、 任意の下地層 （例えば二酸化珪素膜） 6 0 Aの上に、 S i 2H6/NH3プラズマを用いて第 1の処理圧力でプ ラズマ C V D処理を行い、 図 1 3 Bに示したように、 第 1のバンド ギャップを有する第 1の窒化珪素膜 7 O Aを形成する。 次に、 図 11 As shown in 3 A, plasma CVD processing is performed on an arbitrary underlayer (eg, silicon dioxide film) 60 A at the first processing pressure using Si 2 H 6 / NH 3 plasma. As shown in FIG. 13B, the first silicon nitride film 7 OA having the first band gap is formed. Next, Figure 1
3 Cに示したように、 第 1の窒化珪素膜 7 O Aの上に、 S i 2H6Z NH3プラズマを用いて第 2の処理圧力でプラズマ C VD処理を行 P T/JP2009/057006 い、 図 1 3 Dに示したように、 第 2のバンドギャップを有する第 2 の窒化珪素膜 7 1 Aを形成する。 これにより、 2層の窒化珪素膜か らなる窒化珪素膜積層体 8 O Aを形成できる。 さらに必要に応じて 、 図 1 3 Eに示したように、 第 2の窒化珪素膜 7 1 Aの上に、 S i 2H6ZNH3プラズマを用いて、 第 3の処理圧力でプラズマ C VD 処理を行い、 図 1 3 Fに示したように、 第 3のバンドギャップを有 する第 3の窒化珪素膜 7 2 Aを形成することもできる。 以降、 ブラ ズマ C VD処理を必要回数繰り返し行うことによって、 所望の層構 造を有する窒化珪素膜積層体 8 O Aを形成できる。 As shown in 3 C, plasma C VD treatment is performed on the first silicon nitride film 7 OA using Si 2 H 6 Z NH 3 plasma at the second treatment pressure. PT / JP2009 / 057006 As shown in FIG. 13D, a second silicon nitride film 71 A having a second band gap is formed. Thereby, a silicon nitride film laminate 8 OA composed of two layers of silicon nitride films can be formed. Further, if necessary, as shown in FIG. 13E, using the Si 2 H 6 ZNH 3 plasma on the second silicon nitride film 71A, plasma C VD at the third processing pressure It is also possible to form a third silicon nitride film 72 A having a third band gap as shown in FIG. Thereafter, the silicon nitride film laminate 8 OA having a desired layer structure can be formed by repeating the plasma CVD process as many times as necessary.
( 0 1 0 4 )  (0 1 0 4)
本発明の窒化珪素膜積層体の製造方法では、 シリコン含有化合物 ガスとアンモニアガスとを含む成膜ガスを用い、 シリコン含有化合 物ガス/アンモニアガス流量比を 0. 0 1 5以上 0. 2以下の範囲 内に設定し、 0. l P a以上 1 3 3 3 P a以下の範囲内から選択さ れる処理圧力でプラズマ C V Dを行なうことにより、 例えば 2. 5 e V〜 7 e Vの範囲内で窒化珪素膜のバンドギヤップを変化させる ことができる。 処理圧力が 0. l P a以上 1 3 3 3 P a以下の範囲 内では、 処理圧力を高くするほど、 形成される窒化珪素膜のバンド ギャップが大きくなる傾向がある。 このため、 上記第 1の処理圧力 、 第 2の処理圧力および第 3の処理圧力を上記 0. l P a以上 1 3 3 3 P a以下の範囲内で選択することにより、 第 1 の窒化珪素膜 7 0 A、 第 2の窒化珪素膜 7 1 Aおよび第 3の窒化珪素膜 7 2 Aのバ ンドギャップの大きさを 2. 5 e V〜 7 e Vの範囲内で制御できる  In the method for producing a silicon nitride film laminate of the present invention, a film-forming gas containing a silicon-containing compound gas and an ammonia gas is used, and a silicon-containing compound gas / ammonia gas flow rate ratio is not less than 0.015 and not more than 0.2. For example, within the range of 2.5 eV to 7 eV by performing plasma CVD at a processing pressure selected from the range of 0. l Pa or more and 1 3 3 3 Pa or less. With this, the bandgap of the silicon nitride film can be changed. When the processing pressure is in the range of 0.1 l Pa or more and 1 3 3 3 Pa or less, the band gap of the formed silicon nitride film tends to increase as the processing pressure increases. Therefore, by selecting the first processing pressure, the second processing pressure, and the third processing pressure within the range of 0.1 l Pa or more and 1 3 3 3 Pa or less, the first silicon nitride The band gap of the film 70A, the second silicon nitride film 71A and the third silicon nitride film 72A can be controlled within the range of 2.5 eV to 7 eV.
( 0 1 0 5 ) (0 1 0 5)
例えば、 0. l P a以上 1 3 3 3 P a以下の範囲内から、 処理圧 力を、 第 1の処理圧力 >第 2の処理圧力〉第 3の処理圧力となるよ うに選択すれば、 バンドギャップの大きさが、 第 1の窒化珪素膜 7 0 A>第 2の窒化珪素膜 7 1 A>第 3の窒化珪素膜 7 2 Aであるェ ネルギ一バンド構造を有する窒化珪素膜積層体 8 0 Aを形成できる 。 また、 逆に、 0. l P a以上 1 3 3 3 P a以下の範囲内から処理 圧力を、 第 1の処理圧力ぐ第 2の処理圧力 <第 3の処理圧力となる ように選択すれば、 バンドギャップの大きさが、 第 1の窒化珪素膜 7 O Aぐ第 2の窒化珪素膜 7 1 Aぐ第 3の窒化珪素膜 7 2 Aである エネルギーバンド構造を有する窒化珪素膜積層体 8 0 Aを形成でき る。 なお、 例えば第 1の処理圧力と第 3の処理圧力を同じに設定す ることで、 第 1の窒化珪素膜 7 0 A =第 3の窒化珪素膜 7 2 Aとな るエネルギーバンドギャップ構造を作ることも可能である。 For example, from the range of 0.1 l Pa or more and 1 3 3 3 Pa or less, the treatment pressure will be 1st treatment pressure> 2nd treatment pressure> 3rd treatment pressure. If selected, the band gap has an energy one band structure in which the first silicon nitride film 70 A> the second silicon nitride film 7 1 A> the third silicon nitride film 7 2 A. A silicon nitride film laminate 80 A can be formed. Conversely, if the processing pressure is selected from the range of 0.1 l Pa or more and 1 3 3 3 Pa or less so that the second processing pressure is less than the first processing pressure <the third processing pressure. The band gap size is the first silicon nitride film 7 OA and the second silicon nitride film 7 1 A and the third silicon nitride film 7 2 A. The silicon nitride film laminate having an energy band structure 8 0 A can be formed. For example, by setting the first processing pressure and the third processing pressure to be the same, an energy band gap structure in which the first silicon nitride film 70 A = the third silicon nitride film 72 A is obtained. It is also possible to make it.
( 0 1 0 6 )  (0 1 0 6)
ここで、 バンドギャップの大きさが例えば 2. 5 e V以上 5 e V 以下の範囲内の窒化珪素膜を形成するには、 シリコン含有化合物ガ ス (例えば S i 2 H6ガス） とアンモニアガスとの比 (シリコン含有 化合物ガス/アンモニアガス流量比） を 0. 0 1 5以上 0. 2以下 の範囲内に設定し、 処理圧力を 0. 1 P a以上 4 P a以下に設定す ることが好ましい。 また、 A rガスの流量は 0〜 ： L 0 0 0 mL/m i n ( s c c m) の範囲内、 好ましくは 5 0〜 8 0 0 mL/m i nHere, in order to form a silicon nitride film whose band gap is in the range of, for example, 2.5 eV or more and 5 eV or less, a silicon-containing compound gas (for example, Si 2 H 6 gas) and ammonia gas are used. (Silicon-containing compound gas / ammonia gas flow ratio) should be set within the range of 0.01 5 or more and 0.2 or less, and the processing pressure should be set to 0.1 Pa or more and 4 Pa or less. Is preferred. The Ar gas flow rate is in the range of 0 to L 0 00 mL / min (sccm), preferably 50 to 80 mL / min.
( s c c m) の範囲内、 N H3ガスの流量は 1 0 0〜 8 0 0 mL / m i n ( s c c m) の範囲内、 好ましくは 1 0 0〜 4 0 0 mL/m i n ( s c c m) の範囲内、 S i 2H6ガスの流量を：！〜 4 0 mLZ m i n ( s c c m) の範囲内、 好ましくは 3〜 2 0 mL/m i n ( s c c m) の範囲内から、 それぞれ上記流量比になるように設定す ることができる。 (sccm), NH 3 gas flow rate is in the range of 100-800 mL / min (sccm), preferably in the range of 100-400 mL / min (sccm), S i 2 H 6 gas flow rate! The flow rate ratio can be set within the range of ˜40 mLZ min (sccm), preferably within the range of 3 to 20 mL / min (sccm).
( 0 1 0 7 )  (0 1 0 7)
また、 バンドギャップの大きさが例えば 5 e V超 7 e V以下の範 囲内の窒化珪素膜を形成するには、 シリコン含有化合物ガス （例え ば S i 2 H 6ガス） とアンモニアガスとの比 （シリコン含有化合物ガ ス Zアンモニアガス流量比） を 0. 0 1 5以上 0. 2以下の範囲内 に設定し、 処理圧力を 8. 9 P a以上 1 3 3 3 P a以下に設定する ことが好ましい。 また、 A rガスの流量は 0〜 ： L 0 0 0 mL /m i n ( s c c m) の範囲内、 好ましくは 5 0〜 8 0 0 mL Zm i n ( s c c m) の範囲内、 NH3ガスの流量は 1 0 0〜 8 0 O mL/m i n ( s c c m) の範囲内、 好ましくは 1 0 0〜 4 0 0 m L /m i n ( s c c m) の範囲内、 S i 2 H6ガスの流量を 1〜 4 0 m L / m i n ( s c c m) の範囲内、 好ましくは 3〜 2 0 mL/m i n ( s c c m) の範囲内から、 それぞれ上記流量比になるように設定する ことができる。 In addition, the band gap size is, for example, in the range of more than 5 eV and less than 7 eV. To form the silicon nitride film in the enclosure, the ratio of silicon-containing compound gas (for example, Si 2 H 6 gas) to ammonia gas (silicon-containing compound gas Z ammonia gas flow rate ratio) is not less than 0.0 15 It is preferable to set the pressure within the range of 0.2 or less, and set the processing pressure to 8.9 Pa or more and 1 3 3 3 Pa or less. In addition, the Ar gas flow rate is in the range of 0 to L 0 00 mL / min (sccm), preferably in the range of 50 to 800 mL Zm in (sccm), and the NH 3 gas flow rate is 1. Within the range of 0 0 to 80 O mL / min (sccm), preferably within the range of 100 to 400 m L / min (sccm), the flow rate of Si 2 H 6 gas is 1 to 40 m Within the range of L / min (sccm), preferably within the range of 30 to 20 mL / min (sccm), the flow rate can be set to the above-mentioned ratio.
( 0 1 0 8 )  (0 1 0 8)
また、 上記いずれの場合も、 プラズマ C VD処理の処理温度は、 載置台 2の温度を 3 0 0 °C以上、 好ましくは 4 0 0 °C以上 6 0 0 °C 以下の範囲内に設定する。  In any of the above cases, the processing temperature of the plasma C VD processing is set so that the temperature of the mounting table 2 is not less than 300 ° C, preferably not less than 400 ° C and not more than 60 ° C. .
( 0 1 0 9 )  (0 1 0 9)
また、 上記いずれの場合も、 プラズマ C VD処理におけるマイク 口波のパワー密度は、 透過板の面積あたり 0. 2 5 6 W/ c m2以 上 2. 0 4 5 W/ c m2以下の範囲内とすることが好ましい。 In any of the above cases, the power density of the microphone mouth wave in the plasma C VD treatment is within the range of 0.2 5 6 W / cm 2 or more and 2.0 45 5 W / cm 2 or less per area of the transmission plate. It is preferable that
( 0 1 1 0 )  (0 1 1 0)
本発明の窒化珪素膜積層体の製造方法では、 シリコン含有化合物 ガスとアンモニアガスとを含む成膜ガスを用い、 シリコン含有化合 物ガス Zアンモニアガス流量比を 0. 0 1 5以上 0. 2以下の範囲 内に設定し、 0. 1 P a以上 1 3 3 3 P a以下の範囲内から選択さ れる処理圧力でプラズマ C VDを行なうことにより、 ウェハ W上に 、 バンドギヤップが異なる窒化珪素膜を交互に堆積させて窒化珪素 膜積層体を形成することができる。 特に、 本発明の窒化珪素膜積層 体の製造方法では、 処理圧力のみによってバンドギャップの大小を 容易に制御できることから、 異なるバンドギャップを有する窒化珪 素膜の積層体を形成する場合に同一チャンバ一内で真空状態を維持 したまま連続的な成膜が可能になり、 プロセス効率を向上させる上 で極めて有利である。 In the method for producing a silicon nitride film laminate of the present invention, a film-forming gas containing a silicon-containing compound gas and an ammonia gas is used, and a silicon-containing compound gas Z ammonia gas flow rate ratio is not less than 0.015 and not more than 0.2. By performing plasma C VD at a processing pressure selected from the range of 0.1 Pa or more and 1 3 3 3 Pa or less, a silicon nitride film having a different band gap on the wafer W is set. Alternately deposited silicon nitride A film stack can be formed. In particular, in the method for manufacturing a silicon nitride film laminate according to the present invention, the size of the band gap can be easily controlled only by the processing pressure. Therefore, when forming a laminate of silicon nitride films having different band gaps, In this way, continuous film formation is possible while maintaining a vacuum state, which is extremely advantageous for improving process efficiency.
( 0 1 1 1 )  (0 1 1 1)
また、 処理圧力の調節のみによって窒化珪素膜のパンドギャップ が容易に調整可能であることから、 様々なバンドギャップ構造の窒 化珪素膜積層体を簡単に製造できる。 そのため、 本発明方法を、 M O S型半導体メモリ装置の電荷蓄積領域としての窒化珪素膜積層体 の形成に適用することにより、 優れたデータ保持特性と、 高速のデ —夕書換え性能と、 低消費電力での動作性能と、 高い信頼性と、 を 同時に兼ね備えた MO S型半導体メモリ装置を製造できる。  In addition, since the panda gap of the silicon nitride film can be easily adjusted only by adjusting the processing pressure, it is possible to easily manufacture silicon nitride film laminates having various band gap structures. Therefore, by applying the method of the present invention to the formation of a silicon nitride film stack as a charge storage region of a MOS type semiconductor memory device, excellent data retention characteristics, high-speed data rewriting performance, and low power consumption This makes it possible to manufacture MOS type semiconductor memory devices that have both the operating performance and high reliability at the same time.
( 0 1 1 2 )  (0 1 1 2)
[半導体メモリ装置の製造への適用例]  [Application example of semiconductor memory device manufacturing]
次に、 図 1 4を参照しながら、 上記各実施の形態に係る窒化珪素 膜の製造方法を半導体メモリ装置の製造過程に適用した例について 説明する。 なお、 以下では、 第 1〜第 3の実施の形態に従って窒化 珪素膜を製造する場合を例示しているが、 第 4および第 5の実施の 形態に従って窒化珪素膜を製造しても良いことはもちろんである。 図 1 4は、 MO S型半導体メモリ装置 6 0 1 の概略構成を示す断面 図である。 MO S型半導体メモリ装置 6 0 1は、 半導体層としての p型のシリコン基板 1 0 1 と、 この p型のシリコン基板 1 0 1上に 積層形成された、 バンドギャップの大きさが異なる複数の絶縁膜と 、 さらにその上に形成されたゲー ト電極 1 0 3 と、 を有している。 シリコン基板 1 0 1 とゲート電極 1 0 3 との間には、 第 1の絶縁膜 1 1 1 と、 第 2の絶縁膜 1 1 2 と、 第 3の絶縁膜 1 1 3 と、 第 4の 絶縁膜 1 1 4と、 第 5の絶縁膜 1 1 5 とが設けられている。 このう ち、 第 2の絶縁膜 1 1 2、 第 3の絶縁膜 1 1 3および第 4の絶縁膜 1 1 4は、 いずれも窒化珪素膜であり、 窒化珪素膜積層体 1 0 2 a を形成している。 Next, an example in which the method for manufacturing a silicon nitride film according to each of the above embodiments is applied to a manufacturing process of a semiconductor memory device will be described with reference to FIG. In the following, a case where a silicon nitride film is manufactured according to the first to third embodiments is illustrated, but a silicon nitride film may be manufactured according to the fourth and fifth embodiments. Of course. FIG. 14 is a cross-sectional view showing a schematic configuration of the MOS type semiconductor memory device 60 1. The MOS type semiconductor memory device 6 0 1 includes a p-type silicon substrate 10 0 1 as a semiconductor layer and a plurality of layers formed on the p-type silicon substrate 1 0 1 and having different band gap sizes. And an insulating film, and a gate electrode 103 formed thereon. Between the silicon substrate 1 0 1 and the gate electrode 1 0 3, there is a first insulating film 1 1 1, second insulating film 1 1 2, third insulating film 1 1 3, fourth insulating film 1 1 4, and fifth insulating film 1 1 5 are provided. Of these, the second insulating film 1 1 2, the third insulating film 1 1 3, and the fourth insulating film 1 1 4 are all silicon nitride films, and the silicon nitride film stack 100 2 a is Forming.
( 0 1 1 3 )  (0 1 1 3)
また、 シリコン基板 1 0 1 には、 ゲート電極 1 0 3の両側に位置 するように、 表面から所定の深さで n型拡散層である第 1のソース • ドレイン 1 0 4および第 2のソ一ス · ドレイン 1 0 5が形成され 、 両者の間はチヤネル形成領域 1 0 6 となっている。 なお、 M O S 型半導体メモリ装置 6 0 1は、 半導体基板内に形成された Pゥエル や p型シリコン層に形成されていてもよい。 また、 本実施の形態は 、 nチャネル M O Sデバイスを例に挙げて説明を行うが、 Pチヤネ ル MO Sデバイスで実施してもかまわない。 従って、 以下に記載す る本実施の形態の内容は、 全て nチャネル MO Sデバイス、 及び、 Pチャネル M O Sデバイスに適用することができる。  In addition, the silicon substrate 10 1 1 includes a first source / drain 10 4 and a second source that are n-type diffusion layers at a predetermined depth from the surface so as to be located on both sides of the gate electrode 103. One drain 10 5 is formed, and a channel forming region 10 6 is formed between the two. Note that the M O S type semiconductor memory device 60 1 may be formed in a P-well or p-type silicon layer formed in the semiconductor substrate. In the present embodiment, an n-channel MOS device will be described as an example, but a P-channel MOS device may be used. Accordingly, the contents of the present embodiment described below can be applied to all n-channel MOS devices and P-channel MOS devices.
( 0 1 1 4 )  (0 1 1 4)
第 1の絶縁膜 1 1 1は、 例えばシリコン基板 1 0 1の表面を熱酸 化法により酸化して形成された二酸化珪素膜 （ S i 02膜） である 。 第 1の絶縁膜 1 1 1のバンドギャップの大きさは例えば 8〜 1 0 e Vの範囲内であり、 膜厚は、 例えば 0 , 5 nm〜 2 0 nmの範囲 内が好ましく、 1 nm〜 3 nmの範囲内がより好ましい。 The first insulating film 1 1 1, for example silicon dioxide film formed by oxidizing the silicon substrate 1 0 1 of the surface thermal acid Act (S i 0 2 film). The band gap size of the first insulating film 1 1 1 is in the range of 8 to 10 eV, for example, and the film thickness is preferably in the range of 0, 5 nm to 20 nm, for example, 1 nm to More preferably within the range of 3 nm.
( 0 1 1 5 )  (0 1 1 5)
窒化珪素膜積層体 1 0 2 aを構成する第 2の絶縁膜 1 1 2は、 第 1 の絶縁膜 1 1 1 の表面に形成された窒化珪素膜 （ S i N膜 ； ここ で、 S i と Nとの組成比は必ずしも化学量論的に決定されず、 成膜 条件により異なる値をとる。 以下、 同様である） である。 第 2の絶 縁膜 1 1 2のバンドギャップの大きさは例えば 5〜 7 e Vの範囲内 であり、 膜厚は、 例えば 2 n m〜 2 0 n mの範囲内が好ましく、 3 nm〜 5 n mの範囲内がより好ましい。 The second insulating film 1 1 2 constituting the silicon nitride film laminate 1 0 2 a is a silicon nitride film (S i N film; where S i is formed on the surface of the first insulating film 1 1 1 The composition ratio of N and N is not necessarily determined stoichiometrically, and takes different values depending on the film formation conditions (the same applies hereinafter). Second absolute The band gap size of the edge film 1 1 2 is in the range of 5 to 7 eV, for example, and the film thickness is preferably in the range of 2 nm to 20 nm, for example, and in the range of 3 nm to 5 nm. More preferred.
( 0 1 1 6 )  (0 1 1 6)
第 3の絶縁膜 1 1 3は、 第 2の絶縁膜 1 1 2上に形成された窒化 珪素膜 （ S i N膜） である。 第 3の絶縁膜 1 1 3のバンドギャップ の大きさは例えば 2. 5〜 4 e Vの範囲内であり、 膜厚は、 例えば 2 nm〜 3 0 nmの範囲内が好ましく、 4 nm〜 l 0 nmの範囲内 がより好ましい。  The third insulating film 1 13 is a silicon nitride film (SiN film) formed on the second insulating film 1 12. The band gap size of the third insulating film 1 1 3 is in the range of 2.5 to 4 eV, for example, and the film thickness is preferably in the range of 2 nm to 30 nm, for example, 4 nm to l A range of 0 nm is more preferable.
( 0 1 1 7 )  (0 1 1 7)
第 4の絶縁膜 1 1 4は、 第 3の絶縁膜 1 1 3上に形成された窒化 珪素膜 （ S i N膜） である。 この第 4の絶縁膜 1 1 4は、 例えば第 2の絶縁膜 1 1 2 と同様のエネルギーバンドギヤップおよび膜厚を 有している。  The fourth insulating film 1 14 is a silicon nitride film (SiN film) formed on the third insulating film 1 13. The fourth insulating film 1 14 has the same energy band gap and film thickness as the second insulating film 1 1 2, for example.
( 0 1 1 8 )  (0 1 1 8)
第 5の絶縁膜 1 1 5は、 第 4の絶縁膜 1 1 4上に、 例えば C VD 法により堆積させた二酸化珪素膜 （ S i 02膜） である。 この第 5 の絶縁膜 1 1 5は、 電極 1 0 3 と第 4の絶縁膜 1 1 4との間でプロ ック層 （バリア層） として機能する。 第 5の絶縁膜 1 1 5のバンド ギャップの大きさは例えば 8〜 1 0 e Vの範囲内であり、 膜厚は、 例えば 2 ηπ！〜 3 0 nmの範囲内が好ましく、 5 n m〜 8 n mの範 囲内がより好ましい。 The fifth insulating film 1 15 is a silicon dioxide film (S i 0 2 film) deposited on the fourth insulating film 1 14 by, for example, the C VD method. The fifth insulating film 115 functions as a blocking layer (barrier layer) between the electrode 103 and the fourth insulating film 114. The band gap size of the fifth insulating film 1 1 5 is in the range of 8 to 10 eV, for example, and the film thickness is, for example, 2 ηπ! The range of ˜30 nm is preferable, and the range of 5 nm to 8 nm is more preferable.
( 0 1 1 9 )  (0 1 1 9)
ゲート電極 1 0 3は、 例えば C VD法により成膜された多結晶シ リコン膜からなり、 コントロールゲート （C G) 電極として機能す る。 また、 ゲート電極 1 0 3は、 例えば W , T i , T a， C u , A 1 , A u , P t等の金属を含む膜であってもよい。 ゲート電極 1 0 3は、 単層に限らず、 ゲート電極 1 0 3の比抵抗を下げ、 M〇 S型 半導体メモリ装置 6 0 1の動作速度を高速化する目的で、 例えば夕 ングステン、 モリブデン、 タンタル、 チタン、 白金それらのシリサ イ ド、 ナイ トライ ド、 合金等を含む積層構造にすることもできる。 ゲート電極 1 0 3は、 図示しない配線層に接続されている。 The gate electrode 103 is made of, for example, a polycrystalline silicon film formed by the CVD method, and functions as a control gate (CG) electrode. In addition, the gate electrode 103 may be a film containing a metal such as W, Ti, Ta, Cu, A1, Au, and Pt. Gate electrode 1 0 3 is not limited to a single layer, but for the purpose of lowering the specific resistance of the gate electrode 103 and increasing the operating speed of the MOO type semiconductor memory device 601, for example, tungsten, molybdenum, tantalum, titanium, A laminated structure including platinum, silicide, alloy, etc. of platinum can also be used. The gate electrode 103 is connected to a wiring layer (not shown).
( 0 1 2 0 )  (0 1 2 0)
また、 MO S型半導体メモリ装置 6 0 1 において、 第 2の絶縁膜 1 1 2、 第 3の絶縁膜 1 1 3および第 4の絶縁膜 1 1 4により構成 される窒化珪素膜積層体 1 0 2 aは、 主に電荷を蓄積する電荷蓄積 領域である。 従って、 第 2の絶縁膜 1 1 2、 第 3の絶縁膜 1 1 3お よび第 4の絶縁膜 1 1 4の形成に際して、 本発明の第 1 の実施の形 態に係る窒化珪素膜の製造方法を適用し、 各膜のバンドギャップの 大きさを制御することによって、 M〇 S型半導体メモリ装置 6 0 1 のデータ書き込み性能やデータ保持性能を調節できる。 また、 本発 明の第 2の実施の形態に係る窒化珪素膜積層体の製造方法を適用し 、 第 2の絶縁膜 1 1 2、 第 3の絶縁膜 1 1 3および第 4の絶縁膜 1 1 4を、 プラズマ C VD装置 1 0 0において処理圧力を一定にし、 シリコン含有化合物ガスノ窒素ガス流量比を変化させることにより 同一処理容器内で連続的に製造することもできる。 さらに、 本発明 の第 3の実施の形態に係る窒化珪素膜積層体の製造方法を適用し、 第 2の絶縁膜 1 1 2、 第 3の絶縁膜 1 1 3および第 4の絶縁膜 1 1 4が異なるバンドギャップとなるように、 プラズマ C V D装置 2 0 0においてウェハ Wへの R Fバイアスの大きさを変化させることに より同一処理容器内で連続的に製造することもできる。  Further, in the MOS type semiconductor memory device 60 1, the silicon nitride film laminated body 10 composed of the second insulating film 1 1 2, the third insulating film 1 13 and the fourth insulating film 1 1 4. 2 a is a charge accumulation region that mainly accumulates charges. Therefore, in forming the second insulating film 1 1 2, the third insulating film 1 1 3, and the fourth insulating film 1 1 4, the manufacture of the silicon nitride film according to the first embodiment of the present invention By applying the method and controlling the size of the band gap of each film, the data write performance and data retention performance of the MOS semiconductor memory device 61 can be adjusted. Further, the second insulating film 1 1 2, the third insulating film 1 1 3, and the fourth insulating film 1 are applied by applying the method for manufacturing the silicon nitride film laminated body according to the second embodiment of the present invention. 14 can be continuously produced in the same processing vessel by changing the silicon-containing compound gas / nitrogen gas flow rate ratio while maintaining the processing pressure constant in the plasma C VD apparatus 100. Furthermore, the second insulating film 1 1 2, the third insulating film 1 1 3, and the fourth insulating film 1 1 are applied by applying the method for manufacturing the silicon nitride film laminate according to the third embodiment of the present invention. It is also possible to manufacture continuously in the same processing container by changing the magnitude of the RF bias applied to the wafer W in the plasma CVD apparatus 200 so that 4 has different band gaps.
( 0 1 2 1 )  (0 1 2 1)
ここでは代表的な手順の一例を挙げて、 本発明方法を MO S型半 導体メモリ装置 6 0 1 の製造に適用した例について説明を行う。 ま ず、 L O C O S (L o c a l O x i d a t i o n o f S i 1 i c o n) 法や S T I ( S h a l l o w T r e n c h I s o 1 a t i o n ) 法などの手法で素子分離膜 （図示せず） が形成された シリコン基板 1 0 1 を準備し、 その表面に、 例えば熱酸化法によつ て第 1の絶縁膜 1 1 1 を形成する。 Here, an example of a typical procedure will be described and an example in which the method of the present invention is applied to the manufacture of the MOS type semiconductor memory device 60 1 will be described. Ma First, prepare a silicon substrate 10 0 1 with an isolation film (not shown) formed by the LOCOS (Local Oxidation of S i 1 icon) method or STI (Shallow Trenches I so 1 ation) method. Then, a first insulating film 1 1 1 is formed on the surface by, eg, thermal oxidation.
( 0 1 2 2 )  (0 1 2 2)
次に、 第 1の絶縁膜 1 1 1 の上に、 プラズマ C VD装置 1 0 0ま たはプラズマ処理装置 2 0 0を用いプラズマ C VD法によって第 2 の絶縁膜 1 1 2、 第 3の絶縁膜 1 1 3および第 4の絶縁膜 1 1 4を 順次形成する。  Next, on the first insulating film 1 1 1, the second insulating film 1 1 2, the third An insulating film 1 1 3 and a fourth insulating film 1 1 4 are sequentially formed.
( 0 1 2 3 )  (0 1 2 3)
第 2の絶縁膜 1 1 2 を形成する場合は、 バンドギヤップが任意の 大きさ例えば 5〜 7 e Vの範囲内となるようにプラズマ C VDの条 件を調節する。 第 3の絶縁膜 1 1 3を形成するときは、 第 2の絶縁 膜 1 1 2を形成する条件とは異なる条件でプラズマ C VDを行い、 バンドギャップが例えば 2. 5 e V〜 4 e Vの範囲内となるように プラズマ C VD条件を調節する。 第 4の絶縁膜 1 1 4を形成すると きは、 第 3の絶縁膜 1 1 3 を形成する条件とは異なる圧力条件例え ば第 2の絶縁膜 1 1 2を形成する場合と同じ圧力条件でプラズマ C V Dを行い、 バンドギャップの大きさが例えば 5〜 7 e Vの範囲内 となるようにプラズマ C V D条件を調節する。 各膜のバンドギヤッ プの大きさは、 前記のとおり、 プラズマ C VD処理の処理圧力を一 定にし、 シリコン含有化合物ガス Z窒素ガス流量比を変化させるこ とにより制御できる。  When forming the second insulating film 1 1 2, the conditions of the plasma C VD are adjusted so that the band gap is an arbitrary size, for example, in the range of 5 to 7 eV. When forming the third insulating film 1 1 3, plasma C VD is performed under conditions different from the conditions for forming the second insulating film 1 1 2, and the band gap is 2.5 eV to 4 eV, for example. Adjust the plasma C VD condition so that it is within the range of. When forming the fourth insulating film 1 1 4, the pressure conditions differ from the conditions for forming the third insulating film 1 1 3, for example, under the same pressure conditions as for forming the second insulating film 1 1 2. Plasma CVD is performed, and the plasma CVD conditions are adjusted so that the band gap is in the range of 5 to 7 eV, for example. As described above, the size of the band gap of each film can be controlled by changing the silicon-containing compound gas Z nitrogen gas flow rate ratio while keeping the plasma C VD treatment pressure constant.
( 0 1 2 4)  (0 1 2 4)
次に、 第 4の絶縁膜 1 1 4の上に、 第 5の絶縁膜 1 1 5 を形成す る。 この第 5の絶縁膜 1 1 5は、 例えば C VD法によって形成する ことができる。 さらに、 第 5の絶縁膜 1 1 5の上に、 例えば C VD 法によってポリシリコン層や金属層、 あるいは金属シリサイ ド層な どを成膜してゲート電極 1 0 3 となる金属膜を形成する。 Next, a fifth insulating film 1 1 5 is formed on the fourth insulating film 1 1 4. The fifth insulating film 1 1 5 is formed by, for example, the C VD method. be able to. Further, a polysilicon film, a metal layer, a metal silicide layer, or the like is formed on the fifth insulating film 115 by, for example, the C VD method to form a metal film to be the gate electrode 103. .
( 0 1 2 5 )  (0 1 2 5)
次に、 フォ トリソグラフィ一技術を用い、 パターン形成したレジ ス トをマスクとして、 前記金属膜、 第 5の絶縁膜 1 1 5〜第 1の絶 縁膜 1 1 1 をエッチングすることにより、 パターン形成されたゲー ト電極 1 0 3 と複数の絶縁膜を有するゲ一ト積層構造体が得られる 。 次に、 ゲート積層構造体の両側に隣接するシリコン表面に n型不 純物を高濃度にイオン注入し、 第 1のソース ' ドレイン 1 0 4およ び第 2のソース · ドレイン 1 0 5を形成する。 このようにして、 図 1 4に示した構造の MO S型半導体メモリ装置 6 0 1 を製造できる  Next, using a photolithography technique, the metal film and the fifth insulating film 115 to the first insulating film 1111 are etched using the patterned resist as a mask. A gate laminated structure having the formed gate electrode 103 and a plurality of insulating films is obtained. Next, n-type impurities are ion-implanted at a high concentration into the silicon surface adjacent to both sides of the gate stacked structure, and the first source and drain 10 4 and the second source and drain 10 5 are connected. Form. In this way, the MOS type semiconductor memory device 60 1 having the structure shown in FIG. 14 can be manufactured.
( 0 1 2 6 ) (0 1 2 6)
なお、 上記例では、 窒化珪素膜積層体 1 0 2 a中の第 3の絶縁膜 1 1 3のバン ドギャップに比べて、 第 2の絶縁膜 1 1 2および第 4 の絶縁膜 1 1 4のバンドギャップを大きく形成したが、 第 2の絶縁 膜 1 1 2および第 4の絶縁膜 1 1 4のバンドギャップに比べて、 第 3の絶縁膜 1 1 3のバンドギャップを大きく してもよい。 また、 第 2の絶縁膜 1 1 2 と第 4の絶縁膜 1 1 4のバンドギャップの大きさ は同じである必要はない。  In the above example, the second insulating film 1 1 2 and the fourth insulating film 1 1 4 are compared with the band gap of the third insulating film 1 1 3 in the silicon nitride film stack 10 2 a. Although the band gap is formed large, the band gap of the third insulating film 1 13 may be made larger than the band gap of the second insulating film 1 1 2 and the fourth insulating film 1 1 4. The band gaps of the second insulating film 1 1 2 and the fourth insulating film 1 1 4 do not need to be the same.
( 0 1 2 7 )  (0 1 2 7)
また、 図 1 4では、 窒化珪素膜積層体 1 0 2 aとして、 第 2の絶 縁膜 1 1 2〜第 4の絶縁膜 1 1 4からなる 3層を有する場合を例に 挙げたが、 本発明方法は、 窒化珪素膜が 2層または 4層以上積層さ れた窒化珪素膜積層体を有する MO S型半導体メモリ装置を製造す る場合にも適用できる。 ( 0 1 2 8 ) Further, in FIG. 14, the silicon nitride film laminated body 10 2 a is exemplified as the case where the silicon nitride film laminated body 10 3 a has three layers including the second insulating film 1 1 2 to the fourth insulating film 1 1 4. The method of the present invention can also be applied to the manufacture of a MOS type semiconductor memory device having a silicon nitride film laminated body in which two or more silicon nitride films are laminated. (0 1 2 8)
以上、 本発明の実施形態を述べたが、 本発明は上記実施形態に制 約されることはなく、 種々の変形が可能である。 例えば、 以上に挙 げた各実施の形態では、 成膜原料ガスとして、 窒素ガスまたはアン モニァガスとジシランを用いる場合を例に挙げて説明したが、 窒素 ガスまたはアンモニアガスと他のシリコン含有化合物ガス例えばシ ラン、 トリシラン、 トリシリルァミンなどを用いても、 シリコン含 有化合物ガス Z窒素ガスまたはアンモニア流量比を変えることによ つて、 膜中に含まれる S i /Nの比をコントロールして、 同様に窒 化珪素膜のバンドギャップの大きさを制御することが可能である。  Although the embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments, and various modifications can be made. For example, in each of the above-described embodiments, the case where nitrogen gas or ammonia gas and disilane are used as the film forming source gas has been described as an example. However, nitrogen gas or ammonia gas and another silicon-containing compound gas, for example, Even if silane, trisilane, trisilylamine, etc. are used, the ratio of Si / N contained in the film is controlled by changing the flow rate ratio of silicon-containing compound gas Z nitrogen gas or ammonia. It is possible to control the size of the band gap of the silicon nitride film.

Claims

1. 複数の孔を有する平面アンテナにより処理室内にマイクロ波 を導入してプラズマを生成するプラズマ C VD装置を用い、 被処理 体上にプラズマ C VD法によって窒化珪素膜を形成する窒化珪素膜 の製造方法であって、 請 1. Using a plasma C VD apparatus that generates plasma by introducing microwaves into a processing chamber using a planar antenna having a plurality of holes, a silicon nitride film is formed on a workpiece by a plasma C VD method. A manufacturing method comprising:
窒素ガスまたはアンモニアガスのいずれか一方とシリコン含有化 合物ガスとを含む成膜ガスを用い、 処理圧力を 0. 1 P a以上 1 3 3 3 P a以下の範囲内で一定に設定し、 前記成膜ガスが窒素ガスを 含む場合シリコン含有化合物ガスと窒素ガスとの流量比 （シリコン 囲  Using a film-forming gas containing either nitrogen gas or ammonia gas and a silicon-containing compound gas, the processing pressure is set constant within a range of 0.1 Pa to 1 3 3 3 Pa, When the deposition gas contains nitrogen gas, the flow rate ratio between the silicon-containing compound gas and nitrogen gas (silicon
含有化合物ガス流量/窒素ガス流量） を 0. 0 0 5以上 0. 2以下 の範囲内から選択し、 前記成膜ガスがアンモニアガスを含む場合シ リコン含有化合物ガスとアンモニアガスとの流量比 （シリコン含有 化合物ガス流量/アンモニアガス流量） を 0. 0 1 5以上 0. 2以 下の範囲内から選択して、 プラズマ C V Dを行い、 バンドギャップ の大きさが 2. 5 e V以上 7 e V以下の範囲内の窒化珪素膜を形成 する C VD工程を備えたことを特徴とする窒化珪素膜の製造方法。 (Contained compound gas flow rate / nitrogen gas flow rate) is selected from the range of 0.005 or more and 0.2 or less, and when the film-forming gas contains ammonia gas, the flow rate ratio of silicon-containing compound gas and ammonia gas ( Select a silicon-containing compound gas flow rate (ammonia gas flow rate) from the range of 0.0 1 5 or more and 0.2 or less, perform plasma CVD, and the band gap size is 2.5 eV or more 7 eV A method for producing a silicon nitride film, comprising a CVD process for forming a silicon nitride film within the following range.
2. 処理圧力を 0. 1 P a以上 4 P a以下の範囲内または 4 0 P a以上 1 3 3 3 P a以下の範囲内で一定に設定することを特徴とす る請求項 1 に記載の窒化珪素膜の形成方法。  2. The processing pressure is set to be constant within a range of 0.1 Pa to 4 Pa, or within a range of 40 Pa to 1 3 3 3 Pa. Of forming a silicon nitride film.
3. 被処理体に高周波をパワー密度 0. 0 l WZ c m2以上 0. 6 4W/ c m2以下の範囲内で供給することを特徴とする請求項 1 に記載の窒化珪素膜の形成方法。 3. The method for forming a silicon nitride film according to claim 1, wherein a high frequency is supplied to the object to be processed within a power density of 0.0 l WZ cm 2 or more and 0.6 4 W / cm 2 or less.
4. 複数の孔を有する平面アンテナにより処理室内にマイクロ波 を導入してプラズマを生成するプラズマ C VD装置を用い、 被処理 体上にプラズマ C VD法によつて窒化珪素膜の積層体を形成する窒 化珪素膜積層体の製造方法であって、 窒素ガスまたはアンモニアガスのいずれか一方とシリコン含有化 合物ガスとを含む成膜ガスを用い、 処理圧力を 0. l P a以上 1 3 3 3 P a以下の範囲内で一定に設定し、 前記成膜ガスが窒素ガスを 含む場合シリコン含有化合物ガスと窒素ガスとの流量比 （シリ コン 含有化合物ガス流量/窒素ガス流量） を 0. 0 0 5以上 0. 2以下 の範囲内から選択し、 前記成膜ガスがアンモニアガスを含む場合シ リコン含有化合物ガスとアンモニアガスとの流量比 （シリコン含有 化合物ガス流量 Zアンモニアガス流量） を 0. 0 1 5以上 0. 2以 下の範囲内から選択して、 プラズマ C VDを行い、 2. 5 e V以上 7 e V以下の範囲内の第 1のバンドギャップを有する窒化珪素膜を 形成する第 1 の C VD工程と、 4. Using a plasma C VD device that generates plasma by introducing microwaves into the processing chamber using a planar antenna with multiple holes, a stack of silicon nitride films is formed on the workpiece using the plasma C VD method A method for producing a silicon nitride film laminate comprising: Using a deposition gas containing either nitrogen gas or ammonia gas and a silicon-containing compound gas, the processing pressure is set to a constant value within the range of 0.1 l Pa to 1 3 3 3 Pa, When the film forming gas contains nitrogen gas, the flow rate ratio of silicon-containing compound gas and nitrogen gas (silicon-containing compound gas flow rate / nitrogen gas flow rate) is selected from the range of 0.005 to 0.2. When the film forming gas contains ammonia gas, the flow rate ratio between the silicon-containing compound gas and the ammonia gas (silicon-containing compound gas flow rate Z ammonia gas flow rate) is within the range of 0.015 to 0.2. And performing a plasma C VD, and a first C VD process for forming a silicon nitride film having a first band gap in a range of 2.5 eV to 7 eV,
前記第 1の C V D工程の前または後に、 窒素ガスまたはアンモニ ァガスのいずれか一方とシリコン含有化合物ガスとを含む成膜ガス を用い、 前記第 1の C VD工程と同じ処理圧力で、 前記成膜ガスが 窒素ガスを含む場合シリコン含有化合物ガスと窒素ガスとの流量比 (シリ コン含有化合物ガス流量 Z窒素ガス流量） を 0. 0 0 5以上 0. 2以下の範囲内で前記第 1 の C V D工程とは異なる範囲に設定 し、 前記成膜ガスがアンモニアガスを含む場合シリコン含有化合物 ガ'スとアンモニアガスとの流量比 （シリコン含有化合物ガス流量/ アンモニアガス流量） を 0. 0 1 5以上 0. 2以下の範囲内で前記 第 1 の C VD工程とは異なる範囲に設定することにより、 2. 5 e V以上 7 e V以下の範囲内で前記第 1のバンドギャップとは異なる 第 2のバンドギャップを有する窒化珪素膜を形成する第 2の C V D 工程と、  Before or after the first CVD step, a film forming gas containing either nitrogen gas or ammonia gas and a silicon-containing compound gas is used, and the film formation is performed at the same processing pressure as the first C VD step. When the gas contains nitrogen gas, the flow rate ratio of silicon-containing compound gas to nitrogen gas (silicon-containing compound gas flow rate Z nitrogen gas flow rate) is within the range of 0.005 to 0.2 but the first CVD When the film forming gas contains ammonia gas, the flow rate ratio between the silicon-containing compound gas and the ammonia gas (silicon-containing compound gas flow rate / ammonia gas flow rate) is not less than 0.015. 0.2 By setting a range different from the first C VD process within the range of 2 or less, it is different from the first band gap within the range of 2.5 eV or more and 7 eV or less. Nitrogen with a band gap of A second C V D forming a silicon film,
を備えたことを特徴とする窒化珪素膜積層体の製造方法。 A method for producing a silicon nitride film laminate, comprising:
5. 前記第 1 の C VD工程と前記第 2の C VD工程を繰り返し行 うことを特徴とする請求項 2に記載の窒化珪素膜積層体の製造方法 5. The method for producing a silicon nitride film laminate according to claim 2, wherein the first C VD step and the second C VD step are repeated.
6. コンピュータ上で動作する制御プログラムが記憶されたコン ピュ一夕読み取り可能な記憶媒体であって、 6. A computer-readable storage medium storing a control program that runs on a computer,
前記制御プログラムは、 実行時に、 複数の孔を有する平面アンテ ナにより処理室内にマイクロ波を導入してプラズマを生成させるプ ラズマ C VD装置を用い、 被処理体上にプラズマ C VD法によって 窒化珪素膜を形成するに際し、  The control program uses a plasma C VD apparatus in which a plasma is generated by introducing microwaves into a processing chamber by a planar antenna having a plurality of holes at the time of execution, and silicon nitride is formed on a workpiece by plasma C VD method. In forming the film,
窒素ガスまたはアンモニアガスのいずれか一方とシリコン含有化 合物ガスとを含む成膜ガスを用い、 処理圧力を 0. 1 P a以上 1 3 3 3 P a以下の範囲内で一定に設定し、 前記成膜ガスが窒素ガスを 含む場合シリコン含有化合物ガスと窒素ガスとの流量比 （シリコン 含有化合物ガス流量/窒素ガス流量） を 0. 0 0 5以上 0. 2以下 の範囲内から選択し、 前記成膜ガスがアンモニアガスを含む場合シ リコン含有化合物ガスとアンモニアガスとの流量比 （シリコン含有 化合物ガス流量 Zアンモニアガス流量） を 0. 0 1 5以上 0. 2以 下の範囲内から選択して、 プラズマ C V Dを行い、 バン ドギャップ の大きさが 2. 5 e V以上 7 e V以下の範囲内の窒化珪素膜を形成 する C V D工程が行われるように、 コンピュータに前記プラズマ C VD装置を制御させるものであることを特徴とするコンピュータ読 み取り可能な記憶媒体。  Using a film-forming gas containing either nitrogen gas or ammonia gas and a silicon-containing compound gas, the processing pressure is set constant within a range of 0.1 Pa to 1 3 3 3 Pa, When the film-forming gas contains nitrogen gas, the flow rate ratio between the silicon-containing compound gas and the nitrogen gas (silicon-containing compound gas flow rate / nitrogen gas flow rate) is selected from the range of 0.005 to 0.2. When the deposition gas contains ammonia gas, the flow rate ratio between silicon-containing compound gas and ammonia gas (silicon-containing compound gas flow rate Z ammonia gas flow rate) is selected within the range of 0.0 1 5 or more and 0.2 or less Then, plasma CVD is performed, and the plasma C VD apparatus is installed in a computer so that a CVD process for forming a silicon nitride film having a band gap size of 2.5 eV or more and 7 eV or less is performed. To control Computer read-storage medium, wherein the door.
7. プラズマ C VD法により被処理体上に窒化珪素膜を形成する プラズマ C VD装置であって、  7. A plasma C VD apparatus for forming a silicon nitride film on a workpiece by a plasma C VD method,
被処理体を載置台に載置して収容する処理室と、  A processing chamber for storing the object to be processed on the mounting table;
前記処理室の前記開口部を塞ぐ誘電体部材と、  A dielectric member that closes the opening of the processing chamber;
前記誘電体部材の外側に設けられ、 前記処理室内にマイク口波を 導入するための複数の孔を有する平面アンテナと、  A planar antenna provided outside the dielectric member, and having a plurality of holes for introducing a microphone mouth wave into the processing chamber;
前記処理室内に原料ガスを供給するガス供給装置と、 前記処理室内を減圧排気する排気装置と、 A gas supply device for supplying a source gas into the processing chamber; An exhaust device for evacuating the processing chamber under reduced pressure;
前記処理室内で、 窒素ガスまたはアンモニアガスのいずれか一方 とシリコン含有化合物ガスとを含む成膜ガスを用い、 処理圧力を 0 . 1 P a以上 1 3 3 3 P a以下の範囲内で一定に設定し、 前記成膜 ガスが窒素ガスを含む場合シリコン含有化合物ガスと窒素ガスとの 流量比 （シリコン含有化合物ガス流量ノ窒素ガス流量） を 0. 0 0 5以上 0. 2以下の範囲内から選択し、 前記成膜ガスがアンモニア ガスを含む場合シリコン含有化合物ガスとアンモニアガスとの流量 比 （シリコン含有化合物ガス流量/アンモニアガス流量） を 0. 0 1 5以上 0. 2以下の範囲内から選択して、 プラズマ C VDを行い 、 バンドギャップの大きさが 2. 5 e V以上 7 e V以下の範囲内の 窒化珪素膜を形成する C V D工程、 が行われるように制御する制御 部と、  In the processing chamber, a film forming gas containing either nitrogen gas or ammonia gas and a silicon-containing compound gas is used, and the processing pressure is kept constant within a range of 0.1 Pa to 1 3 3 3 Pa. When the film-forming gas contains nitrogen gas, the flow rate ratio of silicon-containing compound gas to nitrogen gas (silicon-containing compound gas flow rate-nitrogen gas flow rate) is within the range of 0.005 to 0.2. When the film-forming gas contains ammonia gas, the flow rate ratio of silicon-containing compound gas to ammonia gas (silicon-containing compound gas flow rate / ammonia gas flow rate) is within the range of 0.0 1 5 or more and 0.2 or less. A control unit that performs plasma C VD and performs a CVD process for forming a silicon nitride film having a band gap size in the range of 2.5 eV to 7 eV.
を備えたことを特徴とするプラズマ C VD装置。 A plasma C VD device characterized by comprising:
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