JP6665726B2 - Film forming equipment - Google Patents

Description

  The present invention relates to a technique for performing a film forming process on a substrate by an ALD (Atomic Layer Deposition) method.

  As a method of performing a film forming process on a substrate, for example, a semiconductor wafer (hereinafter, referred to as a “wafer”), a plurality of types of reactive gases (a first reactive gas and a second reactive gas) reacting with each other are sequentially applied to the wafer. The so-called ALD method and the MLD (M molecular Layer Deposition) method (hereinafter collectively referred to as ALD method) in which a reaction product is supplied to a reactor to deposit a reaction product are known.

  For example, as shown in Patent Document 1, in the ALD method, a wafer is mounted on a mounting table provided in a processing container in which a film forming process is performed, and a gas shower head is provided so as to face the wafer. 2. Description of the Related Art There is known a technique in which a plurality of types of reactive gases are selectively supplied to a wafer from a gas supply hole provided in a gas shower head.

JP 2014-98202 A: Paragraphs 0027 to 0030, FIGS.

  Here, in general, the gas shower head uniformly supplies the reaction gas to the entire surface of the wafer, and thus a large number of gas supply holes are provided on the entire gas supply surface (the bottom plate in Patent Document 1) covering the wafer to be formed. Structure. Therefore, the volume of the internal flow path in the gas shower head tends to increase as the diameter of the wafer increases.

  In particular, when supplying a plurality of types of reaction gases using a common internal flow path, one reaction gas is supplied and then another gas is supplied in order to prevent deposition of reaction products in the gas shower head. Before starting the supply, a purge operation for replacing the reaction gas with an inert gas is required.

  Due to these factors, in a gas shower head having a large volume of the internal flow path, the time required for the reaction gas remaining in the internal flow path to be sufficiently exhausted during the purge operation, and the time required for the next reaction gas to be discharged after the completion of the barge. There is a tendency that the time from the start of the supply until the high concentration of the reaction gas reaches the surface of the wafer becomes longer. In particular, in the ALD method in which the switching of the reaction gas is performed many times, even a slight increase in the time required for each operation greatly affects the entire time of the film formation process from the start to the completion of the film formation.

  Further, the reaction gas supplied toward the wafer flows through a space between the wafer and the gas supply surface and is exhausted to the outside of the processing chamber. For this reason, when switching the reaction gas in the processing chamber, it is necessary for the reaction gas supplied to the central portion of the wafer to reach the peripheral portion of the wafer, and it is necessary to increase the diameter of the wafer. The switching time of the reaction gas in the processing container also tends to be long.

  The present invention has been made under such circumstances, and an object thereof is to provide a technique for minimizing a reaction gas supply flow path and a diffusion region of a reaction gas after being supplied into a processing container. It is in.

The film forming apparatus of the present invention is a film forming apparatus that performs a film forming process on a substrate,
A mounting table on which a substrate to be formed is mounted, which is disposed in a processing container that is evacuated by an exhaust unit,
A rotation drive unit for rotating the mounting table around a rotation axis extending in a direction intersecting with the center of the substrate mounted on the mounting table,
A first gas discharge port for discharging a first reaction gas adsorbed on the substrate is formed toward an elongated region connecting a central portion and a peripheral portion of the surface of the substrate that rotates together with the mounting table. One gas nozzle,
A second gas supply unit for supplying a second reaction gas that forms a film by reacting with the first reaction gas in the processing container ;
A plurality of sets of a mounting table, a rotation drive unit, and a first gas nozzle are provided in the processing container .

  The present invention discharges a first reaction gas using a first gas nozzle toward an elongated region connecting a central portion and a peripheral portion of a surface of a substrate, and rotates the substrate around the central portion by rotating the substrate around the central portion. Since the first reaction gas is supplied to the entire surface of the substrate, it is possible to perform the film formation process on the substrate while minimizing the supply channel of the first reaction gas and the supply region of the reaction gas after being supplied into the processing container. it can.

It is a vertical side view of the film-forming apparatus which concerns on embodiment. FIG. 2 is a plan view of a ceiling surface side of the film forming apparatus. FIG. 3 is a plan view of a mounting table side of the film forming apparatus. FIG. 3 is a first operation diagram of the film forming apparatus. FIG. 3 is a second operation diagram of the film forming apparatus. FIG. 9 is a third operation diagram of the film forming apparatus. It is an enlarged view of the 1st gas nozzle provided with the swing mechanism. It is a vertical side view of the film-forming apparatus which concerns on a 1st modification. FIG. 9 is a cross-sectional plan view of a film forming apparatus according to a first modification. It is a vertical side view of the film-forming apparatus which concerns on a 2nd modification. It is a top view on the ceiling side of the film forming apparatus according to the second modification. It is a vertical side view of the film-forming apparatus which concerns on a 3rd modification. FIG. 9 is a first operation diagram of the film forming apparatus according to the second embodiment. It is a top view on the ceiling side of the film forming apparatus according to the second embodiment. FIG. 9 is a second operation diagram of the film forming apparatus according to the second embodiment. FIG. 9 is a first operation diagram of the film forming apparatus according to the third embodiment. It is a top view on the ceiling surface side corresponding to the 1st operation view concerning a 3rd embodiment. FIG. 11 is a second operation diagram of the film forming apparatus according to the third embodiment. It is a top view on the ceiling surface side corresponding to the 2nd operation view concerning a 3rd embodiment. It is an action figure of the modification of the film-forming device concerning a 3rd embodiment. It is a top view by the ceiling side of the modification of the film-forming apparatus concerning a 3rd embodiment.

  Hereinafter, the configuration of the film forming apparatus 1 according to the embodiment of the present invention will be described with reference to FIGS. The film forming apparatus 1 includes a processing container 11, a mounting table 21 disposed in the processing container 11, a first gas nozzle 3 that supplies a reaction gas toward a wafer W mounted on the mounting table 21, It has.

  The processing container 11 includes a top plate 12 and a container body 13, and is configured as a substantially flat cylindrical vacuum container. The container main body 13 forms a side wall and a bottom of the processing container 11. A loading / unloading port 141 for loading / unloading the wafer W and a gate valve 142 for opening / closing the loading / unloading port 141 are provided on a side wall of the container body 13.

  Inside the processing chamber 11, a mounting table 21 made of a disk having a diameter larger than the wafer W (for example, 300 mm in diameter) on which a film is to be formed is horizontally disposed. A circular concave portion capable of accommodating the wafer W to be formed is formed on the upper surface of the mounting table 21, and an electrostatic chuck (not shown) for fixing the wafer W is provided in a mounting area in the concave portion. Have been. When the wafer W is mounted on the predetermined mounting area, the mounting table 21 and the wafer W are arranged substantially concentrically.

A rotation shaft 22 extending in the up-down direction (direction intersecting the surface of the wafer W) is provided at a central portion on the lower surface side of the mounting table 21 (below the central portion of the wafer W mounted on the mounting table 21). ing. The rotation shaft 22 penetrates the bottom plate of the container body 13, and a lower end portion thereof is provided with a rotation drive unit 23 including an electric motor for rotating the mounting table 21 around the rotation shaft 22. Further, the rotation drive unit 23 is provided at a transfer position where the wafer W is transferred to and from an external wafer transfer mechanism that enters the processing chamber 11 through the transfer port 141, and a position where the film formation processing of the wafer W is performed. There is also a function of raising and lowering the mounting table 21 between a film forming position set above the transfer position.
Further, at a position where the rotating shaft 22 penetrates the bottom plate of the container body 13, a bearing portion 18 having a sealing mechanism for holding the rotating shaft 22 rotatably and keeping the inside of the processing container 11 airtight is provided. Have been.

  A heater 15 is arranged between the bottom plate of the container body 13 and the mounting table 21 so as to correspond to the mounting area of the wafer W on the upper surface side of the mounting table 21. The heater 15 is composed of, for example, a resistance heating element, generates heat by electric power supplied from a power supply unit (not shown), and causes a reaction of a reaction gas (first reaction gas, second reaction gas) supplied to the wafer W to progress. The wafer W on the mounting table 21 is heated to a suitable temperature. A temperature detection unit (not shown) for measuring the temperature of the wafer W is provided in the processing chamber 11, and the output of the heater 15 is increased or decreased based on the temperature detected by the temperature detection unit, thereby setting the wafer W in advance. Can be heated to a predetermined temperature.

  Here, in order to prevent the reaction product generated by the reaction of the reaction gas from accumulating on the surface of the heater 15, a partition member may be provided to partition the space above the mounting table 21 from the space below the mounting table 21. . Further, the upper surface of the heater 15 may be covered with a heater cover made of a material that transmits electromagnetic waves radiated from the heater 15.

  A first gas nozzle 3 for discharging a reaction gas to the wafer W is provided above the mounting table 21. As shown in FIGS. 1 to 3, the first gas nozzle 3 of the present example is configured by a hollow elongated tube material inside, and is formed in a radial direction connecting a central portion to a peripheral portion of the wafer W mounted on the mounting table 21. The wafer W is arranged along the surface (upper surface) of the wafer W.

  As shown in FIGS. 1 and 2, the first gas nozzle 3 is accommodated in a concave portion 121 provided on the lower surface of the top plate 12 so as to match the contour shape of the first gas nozzle 3, and the lower surface of the first gas nozzle 3 The height position and the height position of the lower surface of the top plate 12 in the area other than the recess 121 are aligned.

  A tube (for example, a circular tube) that forms the first gas nozzle 3 has a diameter of about 5 to 50 mm, and is formed between the surface of the wafer W mounted on the mounting table 21 and the lower surface of the first gas nozzle 3. The height of the gap is adjusted to about 1 to 50 mm.

  In the first gas nozzle 3, the above-described both end surfaces on the central portion side and the peripheral portion side are closed, while the lower surface of the first gas nozzle 3 is provided with a plurality of first gas nozzles 3 along the extending direction of the first gas nozzle 3. One gas discharge port 312 is provided at an interval from each other. As a result, the reaction gas flowing into the first gas flow path 311, which is the internal space of the first gas nozzle 3, passes through these first gas discharge ports 312 to a region below the first gas nozzle 3 (on the mounting table 21). (A long and narrow region connecting the central portion and the peripheral portion of the wafer W placed on the wafer W).

  As shown in FIG. 2 when the first gas nozzle 3 is viewed from the lower surface side, the first gas nozzle 3 of the present embodiment has a configuration in which a plurality of small-hole-shaped first gas discharge ports 312 are arranged in a line. However, the configuration and arrangement of the first gas discharge ports 312 are not limited to this example. For example, a plurality of rows of the small gas-shaped first gas discharge ports 312 may be provided. Alternatively, one or more slit-shaped first gas discharge ports 312 extending along the length direction of the first gas nozzle 3 may be provided.

  The opening direction (reaction gas discharge direction) of the first gas discharge port 312 provided on the lower surface of the first gas nozzle 3 is preferably vertically downward perpendicular to the surface of the wafer W mounted on the mounting table 21. It is preferable to set. However, as long as the flow of the reaction gas discharged from the first gas discharge port 312 can reach the surface of the wafer W on the mounting table 21, the first gas discharge port 312 is opened obliquely downward. Good.

  The length of the first gas nozzle 3 extending in the radial direction of the wafer W and the length of the region where the first gas discharge port 312 is formed may be shorter than the radius of the wafer W (for example, 150 mm). Good. If the first gas discharge port 312 is provided at a position where the reaction gas flowing out from the lower surface of the first gas nozzle 3 to the periphery can reach the center (rotation center in this example) or the end of the wafer W, the rotating wafer It is possible to supply the reaction gas to the entire surface of W.

  A gas supply line 32 is connected to the upper surface of the support shaft 33, and the gas supply line 32 is branched into, for example, three. On the base end side of the branch line, a source gas supply source 41, a purge gas supply source, and an oxygen gas supply source 43 are provided via a flow rate controller 40 having a mass flow controller 401 and an opening / closing valve V, respectively. I have.

From the source gas supply source 41, a gas serving as a source of a film to be formed on the wafer W is supplied. The source gas is a first reaction gas that is discharged from the first gas nozzle 3 and adsorbed on the wafer W. . For example, when performing a film forming process of forming a silicon oxide film, the raw material gas is 3DMAS (Tris (dimethylamino) silane: SiH [N (CH 3) 2] 3) and BTBAS (Bis (tertiary-butyl- amino) silane, SiH2 A case where (NH—C (CH ₃ ) ₃ ) ₂ ) or the like is used can be exemplified.

  From the oxygen gas supply source 43, an oxygen gas, which is a second reaction gas that reacts with the source gas adsorbed on the wafer W to form a silicon oxide film, is supplied. In the film forming apparatus 1 of the present example, the supply of the oxygen gas (the second reaction gas) to the wafer W is performed using the first gas nozzle 3 to which the source gas (the first reaction gas) is supplied. From this viewpoint, the first gas nozzle 3 that discharges the oxygen gas, which is the second reaction gas, toward the wafer W constitutes a second gas supply unit of the present example.

  A nitrogen gas, which is an inert gas, is supplied from a purge gas supply source. The nitrogen gas is a reaction gas (source gas or oxygen gas) remaining in the first gas nozzle 3 or the gas supply line 32 when switching the gas supplied to the wafer W between the source gas and the oxygen gas. Plays a role of a purge gas for discharging the gas.

Further, as shown in FIGS. 1 and 2, the film forming apparatus 1 of the present embodiment evacuates the inside of the processing container 11 from exhaust ports 161 and 171 provided at two positions on the top plate 12 of the processing container 11. It has a configuration.
Of the two exhaust ports, the central-portion-side exhaust port 161 is arranged at a position facing the central portion of the wafer W mounted on the mounting table 21. More specifically, the central-portion-side exhaust port 161 opens at a position above one end of the first gas nozzle 3 housed in the recess 121 on the central portion side of the wafer W. The central exhaust port 161 is connected to an exhaust pipe 162 provided with the exhaust section 101 on the downstream side.

  The other peripheral edge side exhaust port 171 is arranged at a position facing the peripheral edge of the wafer W mounted on the mounting table 21. In detail, the peripheral-portion-side exhaust port 171 opens at a position above one end of the first gas nozzle 3 housed in the recess 121 on the peripheral portion side of the wafer W. The peripheral side exhaust port 171 is connected to an exhaust pipe 162 provided with the exhaust section 102 on the downstream side.

  The exhaust units 101 and 102 are configured by, for example, a vacuum pump or the like, and can independently adjust the amount of exhaust from the central exhaust port 161 and the peripheral edge exhaust port 171. Vacuum pumps different from each other may be provided in the exhaust units 101 and 102, or a common vacuum pump may be provided as the exhaust units 101 and 102. May be independently adjusted.

  Further, as shown in FIG. 1, the film forming apparatus 1 is provided with a controller 8. The control unit 8 includes a computer having a CPU (Central Processing Unit) (not shown) and a storage unit. The storage unit moves the wafer W received by the mounting table 21 to a processing position. A step for outputting a control signal relating to an operation from the supply of the source gas and the oxygen gas from the first gas nozzle 3 while rotating the wafer W to the unloading of the wafer W after performing the film forming process by the ALD method ( Instruction) group is recorded. This program is stored in a storage medium such as a hard disk, a compact disk, a magnet optical disk, and a memory card, and is installed in the storage unit therefrom.

Hereinafter, an operation of performing a film forming process by the ALD method using the film forming apparatus 1 of the present embodiment will be described with reference to FIGS.
First, the mounting table 21 is lowered to the transfer position, and the wafer W to be film-formed is received via a transfer pin (not shown) from the wafer transfer mechanism that has entered the processing chamber 11 from the loading / unloading port 141. Place on.

  When the wafer W is received, the wafer transport mechanism is withdrawn from the processing chamber 11, the gate valve 142 is closed, and the mounting table 21 is raised to the film forming position. Next, while the rotation of the mounting table 21 is started, the inside of the processing chamber 11 is evacuated from the central portion side exhaust port 161 and the peripheral portion side exhaust port 171, and the wafer W is heated by the heater 15.

  When the pressure in the processing chamber 11 decreases to the set pressure and the temperature of the wafer W reaches the set temperature, the opening / closing valve V on the outlet side of the source gas supply source 41 is opened, and the source material having a predetermined flow rate toward the first gas nozzle 3 is opened. Supply gas (FIG. 4). The source gas supplied from the source gas supply source 41 flows into the first gas passage 311 from the gas supply line 32, spreads through the first gas passage 311, and then passes through each first gas outlet 312. Is discharged downward.

  The source gas discharged from the first gas discharge port 312 flows as a jet along the opening direction of the first gas discharge port 312, and reaches the wafer W rotating with the mounting table 21. As a result, at the position where the jet flows reach, the source gas is supplied to the surface of the wafer W in a state of direct injection, and the adsorbed layer of the source gas molecules is efficiently formed with the contact with the high-concentration source gas. be able to.

  The raw material gas that has reached the wafer W changes its flow direction, and flows out from the lower surface of the first gas nozzle 3 toward the periphery as indicated by a broken arrow in FIG. Also in this flow, since the source gas comes into contact with the surface of the wafer W, an adsorption layer of the source gas molecules is also formed in the peripheral region below the first gas nozzle 3.

  By supplying the source gas during at least one rotation of the wafer W, the surface of the wafer W is scanned by the source gas discharged from the first gas nozzle 3 extending in the radial direction of the wafer W, and the surface of the wafer W is scanned. An adsorption layer for the source gas can be formed on the entire surface. The period during which the source gas is supplied is not limited to the period during which the wafer W rotates once, but the supply of the source gas may be continued during the period when the wafer W rotates multiple times.

  The raw material gas supplied from the first gas nozzle 3 toward the surface of the wafer W flows through a peripheral region below the first gas nozzle 3 and then flows upward as indicated by a broken arrow in FIG. To the processing container 11 via the central exhaust port 161 and the peripheral exhaust port 171 provided above both ends of the first gas nozzle 3 (the central portion and the peripheral edge of the wafer W). It is discharged outside. At this time, the amount of exhaust of the source gas in the length direction of the first gas nozzle 3 (that is, in the radial direction of the wafer W) is adjusted by independently adjusting the exhaust amount from the central exhaust port 161 and the peripheral exhaust port 171. The flow balance can be changed.

  By adjusting the balance of the flow of the source gas, the supply amount of the source gas reaching the surface of the wafer W per unit time can be changed in the radial direction of the wafer W. Since the supply amount of the source gas affects the thickness of the film formed on the wafer W and the amount of the source gas adsorbed, the exhaust amount control from the center side exhaust port 161 and the peripheral edge side exhaust port 171 is performed. Accordingly, it is also possible to control the thickness distribution of the wafer W in the radial direction.

  When the supply of the source gas is performed for a preset period, the supply of the source gas from the source gas supply source 41 is stopped, and the opening / closing valve V on the outlet side of the purge gas supply source is opened, and the supply of the source gas is performed toward the first gas nozzle 3. A flow of nitrogen gas is supplied (FIG. 5). With the nitrogen gas supplied from the source gas supply source 41, the source gas remaining in the first gas nozzle 3 and the gas supply line 32 is exhausted to the processing vessel 11 side, and is further externally discharged through the respective exhaust ports 161 and 171. Is discharged to

  At this time, since the first gas flow path 311 is formed of an elongated tube, the purge in the first gas flow path 311 can be performed in a shorter time as compared with a gas shower head provided so as to cover the entire surface of the wafer W. Operation can be completed.

  Also in the processing vessel 11, the raw material gas supplied from the first gas nozzle 3 is supplied to a relatively narrow area around the first gas nozzle 3, and then the exhaust port provided above the first gas nozzle 3. The gas is exhausted to the outside from 161 and 171. For this reason, the time required for the purge operation in the processing chamber 11 is shorter than in the case where the source gas is supplied so as to spread over the entire space above the wafer W mounted on the mounting table 21.

  When the supply of the nitrogen gas is performed for a preset time during which the source gas in the first gas passage 311 and the processing container 11 is sufficiently discharged, the supply of the nitrogen gas from the purge gas supply source is stopped, while the supply of the oxygen gas is stopped. The on-off valve V on the outlet side of the supply source 43 is opened, and a predetermined flow rate of oxygen gas is supplied to the first gas nozzle 3 (FIG. 6).

  The oxygen gas is discharged from the first gas nozzle 3 toward the surface of the wafer W by the same operation as that of the source gas, and reacts with the source gas molecules adsorbed on the surface of the wafer W to form a film substance (in this example, film material). Silicon oxide) is produced.

  By supplying oxygen gas during at least one rotation of the wafer W, the surface of the wafer W is scanned by the oxygen gas discharged from the first gas nozzle 3 extending in the radial direction of the wafer W, and the surface of the wafer W is scanned. The adsorption layer of the raw material gas adsorbed on the entire surface becomes a molecular layer of the film substance.

The supply of the oxygen gas is performed only for a period sufficient for causing the adsorption layer of the source gas formed on the wafer W to react. The length of this period may be different from the supply period of the source gas from the source gas supply source 41.
Also, regarding the amount of exhaust from the center-side exhaust port 161 and the peripheral-portion-side exhaust port 171, the amount of exhaust from each of the exhaust ports 161 and 171 may be changed with respect to the supply of the source gas.

  When the supply of the oxygen gas is performed for a preset period, the supply of the oxygen gas from the oxygen gas supply source 43 is stopped, and the opening / closing valve V on the outlet side of the purge gas supply source is opened. A purge operation is performed by supplying a nitrogen gas at a flow rate (FIG. 5).

By repeating the above-described ALD cycle of “source gas supply → purge operation → oxygen gas supply → purge operation” several tens to several hundred times, a film having a desired thickness (a silicon oxide film in this example) is formed on the surface of the wafer W. ) Can be laminated.
The ALD cycle is executed a predetermined number of times, and when a film having a desired film thickness is formed on the surface of the wafer W, the execution of the ALD cycle ends. Next, the rotation of the mounting table 21, the heating of the wafer W by the heater 15, and the exhaust from the exhaust ports 161 and 171 are stopped, and the mounting table 21 is lowered from the film forming position to the transfer position. Thereafter, the wafer transport mechanism is advanced into the processing chamber 11, the wafer W is transferred from the mounting table 21 to the wafer transport mechanism in a procedure opposite to the loading procedure, and the wafer W after the film forming process is unloaded from the processing chamber 11. Then, the transfer of the next wafer W is waited for.

The film forming apparatus 1 according to the present embodiment has the following effects. A first gas nozzle 3 is used to discharge a source gas (a first reaction gas) and an oxidizing gas (a second reaction gas) toward an elongated region connecting a central portion and a peripheral portion of the surface of the wafer W, and a central portion is formed. Since each reaction gas is supplied to the entire surface of the wafer W by rotating the wafer W around the unit, the reaction gas is supplied to the supply flow path (first gas flow path 311) or after being supplied into the processing chamber 11. The film formation process of the wafer W can be performed while minimizing the supply region of the reaction gas. As a result, for example, the purging operation can be completed in a short time, the replacement property of the reactive gas in the first gas nozzle 3 and the processing container 11 is improved, and the time required for the film forming process of one wafer W is shortened. The productivity of the film forming apparatus 1 can be improved.
Hereinafter, a variation of the film forming apparatus 1 of the present example will be described with reference to FIGS. In these drawings, components common to the film forming apparatus 1 described with reference to FIGS. 1 to 6 are denoted by the same reference numerals as those used in FIGS.

In the above-described example of the film forming apparatus 1, the amount of the source gas in the length direction of the first gas nozzle 3 is adjusted by independently adjusting the exhaust amount from the two central-port-side exhaust ports 161 and the peripheral-portion-side exhaust port 171. An example in which the flow balance of oxygen and oxygen gas (reactive gas) is changed is shown. On the other hand, the method of changing the balance of the flow of the reaction gas along the length of the first gas nozzle 3 is not limited to the above-described example.
For example, as shown in FIG. 7, the first gas nozzle 3 is disposed to be inclined along the radial direction of the wafer W, and the first gas nozzle 3 of the first gas nozzle 3 is disposed between the central part and the peripheral part of the wafer W. By changing the distance from the outlet 312 to the surface of the wafer W, the balance of the flow of the reaction gas may be changed.

Further, in the film forming apparatus 1 of FIG. 7, the first gas nozzle 3 is arranged around a support shaft 33 attached to the top plate 12 of the processing container 11 so that the inclination of the first gas nozzle 3 can be changed. A swing mechanism for rotating is provided. In this case, a space for movement in which the first gas nozzle 3 that moves along with the rotation operation is disposed on the upper surface of the concave portion 121 that accommodates the first gas nozzle 3 or the penetrating portion of the gas supply line 32 in the top plate 12. Are formed. Further, when the above-mentioned space for movement is formed in the penetrating portion of the gas supply line 32, the processing container 11 is in a state of communicating with the outside. Therefore, as shown in FIG. By providing the gas supply line 32 through a flange 322 provided at the upper end of the bellows 321, airtightness in the processing container 11 may be maintained.
Here, it is not an essential requirement that the first gas nozzle 3 is provided with a swinging mechanism, and the first gas nozzle 3 may be fixedly arranged in an inclined state.

  8 and 9 show an example of a film forming apparatus 1a in which a plurality of sets (five in this example) of a set of the mounting table 21, the rotary drive unit 23, and the first gas nozzle 3 are provided in a common processing container 11. ing. In the film forming apparatus 1a, the equipment configuration such as the mounting table 21, the rotation drive unit 23, and the first gas nozzle 3 is the same as the example of the film forming apparatus 1 described with reference to FIGS.

  In the film forming apparatus 1a, a revolving mechanism that revolves each mounting table 21 at a position where the wafer W can be transferred to and from a wafer transfer mechanism that enters from the loading / unloading port 141 is provided. That is, the rotation drive units 23 of each set are supported by the support arms 61 provided to extend radially from the common revolution shaft 62. At this time, when the revolving shaft 62 is rotated around the vertical axis by the revolving drive unit 63, the respective rotating shafts 22 move along the revolving orbit 192 provided on the bottom surface of the top plate 12, thereby moving the mounting table 21. Can be done.

In the above-described film forming apparatus 1 a, the bottom plate of the container body 13 in the area inside the orbit 192 is supported by the top plate 12 via the support 191. Further, since the inside of the processing container 11 communicates with the atmosphere below the container main body 13 via the orbit 192, in order to keep the inside of the processing container 11 airtight, each set of the rotation drive unit 23 and the mounting table 21 (The support arm 61, the revolving shaft 62, and the revolving drive unit 63) are accommodated in a bottom container 64 that covers the bottom plate of the container body 13 from the lower surface side.
In addition, in the film forming apparatus 1a shown in FIGS. 8 and 9, based on the film forming apparatus 1 having the structure described with reference to FIGS. Although an example of providing a set is shown, based on various film forming apparatuses 1 b to 1 e described below with reference to FIGS. 10 to 21, the mounting table 21, the rotation drive unit 23, the first gas nozzles 3 a to 3 b, etc. Of course, a configuration in which a pair is provided may be adopted.

Here, in the film forming apparatus 1 shown in FIGS. 1 to 3, the case where the first gas nozzle 3 is shared as the second gas supply unit for supplying the second reaction gas has been described. In contrast to this example, the second gas supply unit may be configured separately from the first gas nozzle 3.
FIGS. 10 and 11 show an example of a film forming apparatus 1 b in which a gas shower head 51 as a second gas supply unit is provided in a region on the lower surface of the top plate 12 around a concave portion 121 containing the first gas nozzle 3. ing.

  The gas shower head 51 is provided to face the mounting table 21 and discharges an oxygen gas (second reaction gas) toward the mounting table 21 (a space for accommodating the wafer W mounted on the mounting table 21). Many second gas discharge ports 512 are provided. A gas diffusion space 511 is provided above the surface where the second gas discharge ports 512 are formed, and a second reaction gas or a purge gas is supplied from the oxygen gas supply source 43 or the purge gas supply source 42 via the gas supply line 52. Operational nitrogen gas is supplied.

Note that even when the gas shower head 51 capable of supplying oxygen gas to almost the entire surface of the wafer W is used, oxygen gas is applied to the surface of the wafer W located below the first gas nozzle 3. There is also a risk that it will not go around. Therefore, the rotation of the mounting table 21 continues even during the period in which the oxygen gas is supplied from the gas shower head 51.
The supply of the source gas from the first gas nozzle 3 and the supply of the oxygen gas from the gas shower head 51 are switched and performed alternately.

  Oxygen gas is less expensive than source gas and can be supplied in large quantities. Therefore, it is possible to supply high-concentration oxygen gas to the entire surface of the wafer W using the gas shower head 51 in a short time. Further, since the oxygen gas itself is not a deposition-causing substance of the reaction product, when the raw material gas and the oxygen gas are supplied from the first gas nozzle 3 and the gas shower head 51 separately, the first gas nozzle is used as the second gas supply unit. As compared with the case where the gas nozzle 3 is commonly used, the purge operation can be completed even if a relatively high concentration of oxygen gas remains in the gas diffusion space 511. For this reason, even when the volume of the gas diffusion space 511 is larger than that of the first gas flow channel 311, it is possible to suppress an increase in the time required for the purge operation.

FIG. 12 is a side view of a space (a space above the mounting table 21) for accommodating the wafer W mounted on the mounting table 21 as a second gas supply unit for supplying an oxygen gas (second reaction gas). The figure shows an example of a film forming apparatus 1b 'provided with a second gas nozzle 53 for discharging a second reaction gas from the second gas nozzle. At the end of the second gas nozzle 53, for example, one second gas discharge port is provided, and oxygen gas discharged from the second gas discharge port diffuses into the space accommodating the wafer W.
Also in this example, the supply of the source gas from the first gas nozzle 3 and the supply of the oxygen gas from the second gas nozzle 53 are switched and performed alternately, and the loading is performed during the supply period of the oxygen gas from the second gas nozzle 53. The rotation of the table 21 is continued.

  Next, the configuration of a film forming apparatus 1c according to the second embodiment will be described with reference to FIGS. In the film forming apparatus 1c of this example, DCS (Dichlorosilane) is used as a source gas as a first reaction gas, and ammonia gas for nitriding DCS is used as a second reaction gas to form a silicon nitride film. The case where the film processing is performed will be described.

  The film forming apparatus 1c of the present example is provided with a plasma forming unit 7 for converting the ammonia gas supplied from the short tubular second gas nozzle 53 into plasma to obtain an active species of ammonia. Although the specific configuration of the plasma forming unit 7 is not limited to a specific configuration, a case where a coil-shaped antenna (not shown) for forming an inductively coupled plasma P of ammonia gas by high frequency power supplied from the power supply unit 71 is provided. Examples can be given.

  Here, since it is generally difficult to form the plasma P in a short time, it is impractical to form the plasma P of the ammonia gas every time the ammonia gas is supplied by switching to the DCS gas. Therefore, in the film forming apparatus 1c of this example, while the film forming process is being performed on the wafer W, the ammonia gas is continuously supplied, and the plasma P of the ammonia gas is constantly formed. .

  As shown in FIGS. 13 and 14, a recess serving as a plasma forming space 122 is formed in the top plate 12 below the plasma forming unit 7, and active species of ammonia generated in the plasma P formed in this region are formed. Flows toward the surface of the wafer W. As shown in FIG. 14, in the film forming apparatus 1c, the plasma forming space 122 having a diameter slightly longer than the radius of the wafer W and having a circular shape in a plan view is positioned adjacent to the first gas nozzle 3a when viewed from the wafer W. Are located in The second gas nozzle 53 may be configured to directly discharge the ammonia gas toward the plasma forming space 122.

As described above, when the ammonia gas plasma P is constantly formed, the activated species of ammonia enter the first gas nozzle 3 to deposit reaction products in the first gas channel 311, The first gas flow path 311 and the first gas discharge port 312 may be blocked.
Therefore, the first gas nozzle 3a provided in the film forming apparatus 1c has a structure for suppressing the entry of the active species of ammonia into the first gas channel 311 to which the DCS gas is supplied.

  As shown in FIG. 13, the first gas nozzle 3a is supplied to the wafer W from the first gas flow path 341 for supplying the DCS gas toward the wafer W on the mounting table 21 and from the first gas flow path 341. An exhaust flow path 342 for exhausting the subsequent DCS gas and the like, a separation gas flow path 343 for supplying a separation gas for partitioning an atmosphere below the first gas nozzle 3a and an atmosphere in the processing chamber 11 are provided. It has three types of flow paths. 13 and 15, the illustration of the first gas flow path 341 and the separation gas flow path 343 is omitted in FIGS.

  The first gas flow path 341 has the same configuration as the first gas flow path 311 of the first gas nozzle 3 shown in FIG. 1, and the DCS gas supplied from the source gas supply source 41 is supplied to the first gas nozzle 3 via the gas supply line 32. The gas flows into one gas flow path 341. A plurality of first gas discharge ports 312 are formed on the lower surface of the first gas flow path 341 along the direction in which the first gas nozzle 3a extends (FIG. 14).

  As shown in FIG. 14, an exhaust port 342a is formed around a region where the first gas discharge port 312 is formed so as to extend along a closed circuit (first closed circuit) surrounding the region. As shown in FIG. 13, the DCS gas and the separation gas supplied to the lower surface side of the first gas nozzle 3a flow into the exhaust passage 342 through the exhaust port 342a. Further, the exhaust passage 342 communicates with the exhaust pipe 172, and the exhaust section 101 connected to the downstream side of the exhaust pipe 172 performs vacuum exhaust.

  As shown in FIG. 14, a separation gas discharge port 343a is formed on the outer peripheral side of the exhaust port 342a so as to extend along a closed path (second closed path) surrounding the exhaust port 342a. The separation gas discharge port 343a communicates with the separation gas flow path 343 shown in FIG. 13, and the separation gas flow path 343 is provided with a separation gas for separating the inside and outside of the separation gas discharge port 343a which is a closed circuit. A certain inert gas, for example, an argon gas is supplied from the separation gas supply source 44.

  Due to the above-described configuration of the first gas nozzle 3a, the first gas flow path 341 is configured such that the gas is exhausted to the exhaust flow path 342 through the exhaust port 342a and the gas is discharged from the separation gas flow path 343 through the separation gas discharge port 343a. By the supply of the separation gas, it can be said that the gas is doubly isolated from the atmosphere in the processing vessel 11 on the outer side of the first gas nozzle 3a.

As a result, even if the plasma P of the ammonia gas is always formed in the processing vessel 11, the active species of ammonia are hardly allowed to enter the first gas flow path 341 side, and the first gas flow path 341 Can suppress the accumulation of the reaction product in the above.
Note that performing both the exhaust of the gas through the exhaust port 342a and the supply of the separation gas through the separation gas discharge port 343a is not an essential requirement, and it is possible to perform only the exhaust from the exhaust port 342a. Good. In addition, the ammonia gas supplied into the processing container 11 is evacuated through an exhaust port (not shown) provided separately in the processing container 11.

  Further, here, as in the case of the first gas nozzle 3a shown in FIGS. 13 and 14, when an exhaust gas flow path 342 and a separation gas flow path 343 are further provided around the first gas flow path 341, as shown in FIG. The gas nozzle 3a becomes longer toward both ends. As a result, as shown in FIG. 13, the end of the first gas nozzle 3a located at the center of the wafer W may be in a state of covering the upper surface of the rotation center of the wafer W. Since the rotation radius is small in the region near the rotation center of the wafer W, the wafer W in the region remains covered by the first gas nozzle 3a.

  Further, since the first gas nozzle 3a exhausts from the exhaust port 342a and supplies the separation gas from the separation gas discharge port 343a, the active gas of the ammonia gas is supplied to the area covered by the first gas nozzle 3a. I can hardly get in. As a result, in the region near the rotation center, nitriding of the DCS adsorbed on the wafer W hardly progresses.

  Based on the above-described problem, as shown in FIG. 13, the film forming apparatus 1c of the present example was first discharged from the first gas discharge port 312 at a close position where the wafer W was brought close to and opposed to the first gas nozzle 3a. A process of adsorbing DCS gas (first reaction gas) to the wafer W is performed. Next, as shown in FIG. 15, the film forming apparatus 1c lowers the mounting table 21 toward a separated position where the distance between the first gas nozzle 3a and the wafer W is wider than the close position, and the first gas nozzle 3a An active species of ammonia (second reaction gas) enters between the wafer and the wafer W. As shown in FIG. 15, while the mounting table 21 is being lowered to the separated position, the supply of the DCS gas from the first gas flow path 341 is stopped, and the exhaust gas and the separation gas flow through the exhaust flow path 342 are stopped. Only the supply of the separation gas from the passage 343 may be executed.

The operation of adsorbing the DCS gas at the close position and the supply of the active species of ammonia to the rotation center side of the wafer W at the separated position are alternately performed at a preset time interval. Even when the wafer W is located at the close position, the wafer W is rotated by the mounting table 21 so that the area outside the vicinity of the rotation center is always nitrided by the active species of ammonia. Has been done.
13 and 15, an example is shown in which the mounting table 21 is raised and lowered using the rotary drive unit 23 having a lifting and lowering function. However, a lifting mechanism is provided on the first gas nozzle 3a side, and It goes without saying that the one gas nozzle 3a may be moved up and down to move between the close position and the separated position.

  Next, a configuration of a film forming apparatus 1d according to the third embodiment will be described with reference to FIGS. In the film forming apparatus 1d, the above-described plasma forming unit 7 and the plasma forming space 122 are formed over a region covering the entire surface of the wafer W. The point that the plasma P of the ammonia gas is always formed by the plasma forming unit 7 is the same as that of the film forming apparatus 1c according to the second embodiment.

  In addition, similarly to the first gas nozzle 3 a described with reference to FIGS. 13 and 14, the first gas nozzle 3 b is configured to supply the DCS gas from the first gas channel 341 and to be below the first gas nozzle 3 b by the exhaust channel 342. , And the supply of the separation gas from the separation gas flow path 343. For this reason, similarly to the case of the first gas nozzle 3a, there is a problem that it is difficult for active species of ammonia gas to enter the region near the rotation center of the wafer W.

Therefore, in the first gas nozzle 3b of the present example, the exhaust pipe 172 connected to the exhaust passage 342 also has a function as a rotation shaft 35 for rotating the first gas nozzle 3b to the side.
As shown in FIGS. 16 and 17, in the film forming apparatus 1d, first, the first gas nozzle 3b is disposed at a processing position facing a long and narrow region connecting the central portion and the peripheral portion of the surface of the wafer W. Then, the DCS gas (first reaction gas) discharged from the first gas discharge port 312 is adsorbed on the substrate.

Next, as shown in FIGS. 18 and 19, the first gas nozzle 3b is moved laterally from the processing position to the retreat position 123 set outside the wafer W, and the first gas nozzle 3b and the wafer W The arrangement relationship is shifted so that the active species (second reaction gas) of ammonia gas can be supplied to the elongated region described above. The rotation shaft 35 that rotatably supports one end of the first gas nozzle 3b at an outer position of the wafer W corresponds to a lateral movement mechanism of the first gas nozzle 3b.
Also in this example, the operation of adsorbing the DCS gas at the processing position and the supply of the active species of ammonia to the rotation center side of the wafer W at the evacuation position are performed alternately at preset time intervals.

  Here, as shown in FIGS. 18 and 19, the side moving mechanism does not move the first gas nozzle 3b to the outside of the wafer W mounted on the mounting table 21 (the retracted position 123 shown in FIG. 19). Not a mandatory requirement. In order to supply the active species of the ammonia gas to the vicinity of the rotation center of the wafer W, it is sufficient to move the first gas nozzle 3b to a position shifted from the vicinity as shown in FIGS.

  In addition, when providing the separation / contact mechanism or the lateral movement mechanism, it is not an essential requirement that the film forming apparatus includes the plasma forming unit 7. For example, also in the film forming apparatuses 1b and 1b ′ shown in FIGS. 10 and 12, when the rotation center of the wafer W is covered with the first gas nozzle 3, it becomes difficult for the second reaction gas to reach the region. A separation / contact mechanism or a side moving mechanism similar to the example described with reference to FIGS.

  In addition, the side moving mechanism is not limited to the case where the configuration for moving the first gas nozzle 3b is adopted, and the mounting table 21 on which the wafer W is mounted may be moved to the side. For example, as shown in FIG. 8, when a mechanism for moving the mounting table 21 (the support arm 61, the revolving shaft 62, the revolving drive unit 63, etc.) is provided, the mechanism is utilized as a side moving mechanism. Is also good.

  Here, in the film forming apparatus 1e shown in FIG. 21, while the source gas for the silicon oxide film is supplied from the first gas nozzle 3b, the oxygen gas is supplied from the second gas nozzle 53 and the oxygen gas is supplied in the plasma forming space 122. Plasma is formed and a silicon oxide film is formed using active species such as ozone. Further, after completing the film forming process on the wafer W, the second gas nozzle 53 of the film forming apparatus 1e switches the oxygen gas supplied from the oxygen gas supply source 43 to perform etching (treatment) of the silicon oxide film. Gas supply source 46 for forming a hydrogen gas plasma is connected.

As described above, the film forming apparatus 1e can also perform film forming processing on the wafer W and other subsequent processing (treatment with the plasma P of hydrogen gas in the example shown in FIG. 20) by switching three types of gases.
Furthermore, for example, two first gas nozzles 3b are provided in the film forming apparatus 1e, and a raw material gas containing a different metal is supplied from each first gas nozzle 3b, and oxidation by plasma of oxygen gas is performed. May be adopted.

In addition, it is not essential to set the first gas nozzles 3, 3a, 3b to a length corresponding to a radius connecting the central portion to the peripheral portion of the wafer W. For example, a region extending from one end of the peripheral portion of the wafer W to the other end of the peripheral portion of the wafer W through the central portion of the wafer W, that is, a length corresponding to the diameter of the wafer W may be provided. In this case, it can be considered that two first gas nozzles 3, 3a, 3b having a length corresponding to the radius of the wafer W are connected.
Further, the first gas nozzles 3, 3a, 3b are not limited to the case where they are constituted by straight pipes as shown in FIGS. 2, 14, 17, and the like, and may have a curved shape when viewed in plan.

  The flow rate of the first reaction gas and the second reaction gas discharged from the first gas nozzles 3, 3 a, and 3 b is such that the reaction gas collides with the wafer W by inertia when discharged from the first gas discharge port 312. However, the present invention is not limited to this case. For example, even if the discharge flow rate is such that the reaction gas is diffused from the first gas discharge port 312 and reaches the surface of the wafer W, the supply path of the reaction gas can be obtained by using the first gas nozzles 3, 3a, and 3b. It is possible to obtain the effect of improving the replaceability of the reaction gas by minimizing the supply region of the first gas flow path 311 and the reaction gas after being supplied into the processing vessel 11.

W Wafer 1, 1a-1e
Film forming apparatuses 101 and 102
Exhaust part 11 Processing container 161 Central part side exhaust port 171 Peripheral part side exhaust port 21 Mounting table 22 Rotary shaft 23 Rotation drive part 3, 3a, 3b
First gas nozzle 312 First gas discharge port 342a Exhaust port 343a Separated gas discharge port 35 Rotating shaft 51 Gas shower head 512 Second gas discharge port 53 Second gas nozzle 7 Plasma forming unit 8 Control unit

Claims (14)

In a film forming apparatus that performs a film forming process on a substrate,
A mounting table on which a substrate to be formed is mounted, which is disposed in a processing container that is evacuated by an exhaust unit,
A rotation drive unit for rotating the mounting table around a rotation axis extending in a direction intersecting with the center of the substrate mounted on the mounting table,
A first gas discharge port for discharging a first reaction gas adsorbed on the substrate is formed toward an elongated region connecting a central portion and a peripheral portion of the surface of the substrate that rotates together with the mounting table. One gas nozzle,
A second gas supply unit for supplying a second reaction gas that forms a film by reacting with the first reaction gas in the processing container ;
A film forming apparatus, wherein a plurality of sets of a mounting table, a rotation drive unit, and a first gas nozzle are provided in the processing container .   2. The second gas supply unit according to claim 1, wherein the second gas supply unit shares the first gas nozzle, switches the first gas nozzle, and discharges the second reaction gas from the first gas discharge port. 3. Film forming equipment.   The second gas supply unit is configured separately from the first gas nozzle, and is provided at a position where the second reaction gas is diffused into a space accommodating a substrate mounted on the mounting table. The film forming apparatus according to claim 1.   The said 2nd gas supply part is provided with the 2nd gas discharge port which discharges a 2nd reactive gas from the side of the space which accommodates the board | substrate mounted on the mounting table, The said 2nd gas supply part. Film forming equipment.   The second gas supply unit is a gas shower head that is provided to face the mounting table and includes a plurality of second gas discharge ports that discharge the second reaction gas toward the mounting table. The film forming apparatus according to claim 3.   A substrate is brought close to and opposed to the first gas nozzle, and a proximity position for adsorbing the first reaction gas discharged from the first gas discharge port to the substrate is located between the first gas nozzle and the substrate more than the proximity position. And a separation / contact mechanism for moving at least one of the mounting table or the first gas nozzle between the first gas nozzle and the substrate so as to allow the second reaction gas to enter between the first gas nozzle and the substrate. The film forming apparatus according to claim 4, further comprising:   A first gas nozzle is disposed so as to face an elongated region connecting a central portion and a peripheral portion of the surface of the substrate, and a first reaction gas discharged from the first gas discharge port is adsorbed on the substrate. The above description between a processing position and a retreat position for displacing an arrangement relationship between the first gas nozzle and the substrate to the side from the processing position so that a second reaction gas can be supplied to the elongated region. The film forming apparatus according to claim 4, further comprising a side moving mechanism configured to move at least one of the mounting table and the first gas nozzle to the side.   The film forming apparatus according to claim 6, further comprising a plasma forming unit for forming a plasma of the second reaction gas in the processing container.   The first gas nozzle is arranged to be inclined with respect to a horizontal direction in order to change a distance from a discharge port to a surface of the substrate between a central portion side and a peripheral portion side of the substrate. The film forming apparatus according to claim 1.   The film forming apparatus according to claim 9, further comprising a swing mechanism for changing a tilt of the first gas nozzle.   The exhaust unit is provided in the processing container, and performs vacuum exhaust from exhaust ports arranged at two positions opposed to a central portion and a peripheral portion of the substrate mounted on the mounting table. The film forming apparatus according to any one of claims 1 to 10, wherein:   The film forming apparatus according to claim 11, wherein the exhaust unit independently adjusts an exhaust amount from an exhaust port at a position facing a central portion of the substrate and at a position facing the peripheral portion. .   The exhaust unit is provided in the first gas nozzle, and extends along a first closed path that surrounds a region where the first gas discharge port is formed, as viewed from a substrate mounted on the mounting table. 11. The film forming apparatus according to claim 1, wherein vacuum exhaust is performed from the exhaust port formed as described above.   A separation gas for separating the inside and outside of the second closed path is supplied to the first gas nozzle from a separation gas discharge port formed to extend along a second closed path surrounding the periphery of the exhaust port. 14. The film forming apparatus according to claim 13, further comprising a separation gas supply unit.