JP2021077754A - Gas supply method and substrate processing apparatus - Google Patents

Abstract

To provide a gas supply method and a substrate processing apparatus which are advantageous for stably supplying gas in a short time when the gas is shunted to a plurality of branch pipes according to a divergence ratio and the shunted gas is supplied to a processing container.SOLUTION: A gas supply method includes the steps of closing a second valve, opening a first valve, and supplying gas to a gas supply pipe, a branch pipe, and a gas diversion ratio control element on the secondary side of a gas flow rate control device when a substrate is processed, detecting that the pressure of the gas supply pipe or the branch pipe on the secondary side of the gas flow rate control device has reached set pressure by a pressure sensor, closing the first valve, and opening the first valve and the second valve to supply the gas to a processing container.SELECTED DRAWING: Figure 1

Description

The present disclosure relates to a gas supply method and a substrate processing apparatus.

In Patent Document 1, pressure ratio control for adjusting the partial flow rate so that the pressure ratio in each processing gas branch flow path becomes the target pressure ratio is executed for the partial flow rate adjusting means, and the processing gas supply means is used. A gas supply method and a substrate processing apparatus for dividing a processing gas into a plurality of branch pipes are disclosed. In this gas supply method, when the pressure in each branch flow path for processing gas becomes stable, the control for the split flow rate adjusting means is performed so as to maintain the pressure in one branch flow path for treatment gas when the pressure is stable. The pressure is switched to constant pressure control, and the additional gas is supplied to the other branch pipe for processing gas by the additional gas supply means.

JP-A-2007-207808

According to the present disclosure, when gas is shunted to a plurality of branch pipes according to the divergence ratio and the shunted gas is supplied to a processing container, it is advantageous to stably supply the gas in a short time. A method and a substrate processing apparatus are provided.

The gas supply method according to one aspect of the present disclosure is
A gas supply device for supplying gas to a processing container for processing a substrate, and at least one gas flow control device provided in a gas supply pipe leading from a gas supply unit to the processing container, and the gas flow control. It is composed of a gas diversion ratio control element provided with a conductance variable flow path having a variable conductance, which is provided in each of two or more branch pipes branching on the secondary side of the device, and two or more gas diversion ratio control elements. The gas divergence ratio control unit, the first valve and the pressure sensor on the secondary side of the gas flow control device and on the primary side of the gas divergence ratio control element, and the secondary side of the gas divergence ratio control element. In a gas supply device with a second valve on the side,
In processing the substrate, the second valve is closed, the first valve is opened, and the gas supply pipe, the branch pipe, and the gas distribution ratio control element on the secondary side of the gas flow rate control device are connected. The process of supplying gas and
A step of detecting that the pressure of the gas supply pipe or the branch pipe on the secondary side of the gas flow rate control device has reached a set pressure by the pressure sensor.
The process of closing the first valve and
It has a step of opening the first valve and the second valve to supply the gas to the processing container.

According to the present disclosure, when gas is shunted to a plurality of branch pipes according to the divergence ratio and the shunted gas is supplied to the processing container, it is advantageous to stably supply the gas in a short time. A gas supply method and a substrate processing apparatus can be provided.

It is a vertical sectional view which shows an example of the substrate processing apparatus which concerns on 1st Embodiment. It is a figure explaining the control of a gas supply device, and is the figure which shows the time history graph of the MFC flow rate and the FRC flow rate. It is a vertical sectional view which shows an example of the substrate processing apparatus which concerns on 2nd Embodiment.

Hereinafter, the gas supply method and the substrate processing apparatus according to the embodiment of the present disclosure will be described with reference to the accompanying drawings. In the present specification and the drawings, substantially the same components may be designated by the same reference numerals to omit duplicate explanations.

[Substrate processing apparatus and gas supply method according to the first embodiment]
First, an example of the substrate processing apparatus and the gas supply method according to the first embodiment of the present disclosure will be described with reference to FIGS. 1 and 2. Here, FIG. 1 is a vertical cross-sectional view showing an example of the substrate processing apparatus according to the first embodiment. Further, FIG. 2 is a diagram for explaining the control of the gas supply device, and is a diagram showing a time history graph of the MFC flow rate and the FRC flow rate.

The substrate processing apparatus 100 shown in FIG. 1 processes various substrates on a rectangular substrate G (hereinafter, simply referred to as “substrate”) for a flat panel display (hereinafter, referred to as “FPD”). An Inductive Coupled Plasma (ICP) processor that implements the method. As the material of the substrate G, glass is mainly used, and depending on the application, a transparent synthetic resin or the like may be used. Here, the substrate treatment includes an etching treatment, a film formation treatment using a CVD (Chemical Vapor Deposition) method, and the like. Examples of the FPD include a liquid crystal display (LCD), electro luminescence (EL), and a plasma display panel (PDP). The substrate G includes a support substrate as well as a form in which a circuit is patterned on the surface thereof. Further, the planar dimensions of the FPD substrate have increased with the passage of generations, and the planar dimensions of the substrate G processed by the substrate processing apparatus 100 are, for example, from the dimensions of about 1500 mm × 1800 mm of the 6th generation to the 10th. Includes at least dimensions up to about 3000 mm x 3400 mm for the 5th generation. The thickness of the substrate G is about 0.2 mm to several mm.

The substrate processing apparatus 100 shown in FIG. 1 is controlled by a rectangular parallelepiped box-shaped processing container 20, a substrate mounting table 70 having a rectangular outer shape in a plan view, which is arranged in the processing container 20 and on which the substrate G is placed. It has a part 90 and. The processing container may have a cylindrical box shape or an elliptical tubular box shape. In this form, the substrate mounting table is also circular or elliptical, and the substrate is mounted on the substrate mounting table. Is also circular.

The processing container 20 is divided into two upper and lower spaces by a metal window 50. The antenna chamber A, which is the upper space, is formed by the upper chamber 13, and the processing region S (processing chamber), which is the lower space, is formed by the lower chamber 17. It is formed. In the processing container 20, a rectangular annular support frame 14 is arranged so as to project inside the processing container 20 at a position at the boundary between the upper chamber 13 and the lower chamber 17, and a metal window is provided on the support frame 14. 50 is attached.

The upper chamber 13 forming the antenna chamber A is formed by the side wall 11 and the top plate 12, and is formed of a metal such as aluminum or an aluminum alloy as a whole.

The lower chamber 17 having the processing region S inside is formed by the side wall 15 and the bottom plate 16, and is formed of a metal such as aluminum or an aluminum alloy as a whole. Further, the side wall 15 is grounded by a ground wire 21.

Further, the support frame 14 is formed of a metal such as conductive aluminum or an aluminum alloy, and can also be referred to as a metal frame.

A rectangular annular (endless) seal groove 22 is formed at the upper end of the side wall 15 of the lower chamber 17, and a seal member 23 such as an O-ring is fitted into the seal groove 22 to support the seal member 23 on the support frame 14. By holding the contact surface, a sealing structure between the lower chamber 17 and the support frame 14 is formed.

On the side wall 15 of the lower chamber 17, a carry-in / out port 18 for carrying in / out the substrate G to / from the lower chamber 17 is provided, and the carry-in / out port 18 is configured to be openable and closable by a gate valve 24. A transport chamber containing a transport mechanism (neither is shown) is adjacent to the lower chamber 17, and the gate valve 24 is controlled to open and close, and the transport mechanism carries in and out the substrate G via the carry-in / out port 18. Will be.

Further, a plurality of exhaust ports 19 are opened in the bottom plate 16 of the lower chamber 17, a gas exhaust pipe 25 is connected to each exhaust port 19, and the gas exhaust pipe 25 is connected to the exhaust device 27 via an on-off valve 26. It is connected to the. The gas exhaust section 28 is formed by the gas exhaust pipe 25, the on-off valve 26, and the exhaust device 27. The exhaust device 27 has a vacuum pump such as a turbo molecular pump, and is configured to evacuate the inside of the lower chamber 17 to a predetermined degree of vacuum during the process. A pressure gauge (not shown) is installed at an appropriate position in the lower chamber 17, and monitor information from the pressure gauge is transmitted to the control unit 90.

The substrate mounting table 70 has a base material 73 and an electrostatic chuck 76 formed on the upper surface 73a of the base material 73.

The base material 73 is formed of a laminate of the upper base material 71 and the lower base material 72. The plan view shape of the upper base material 71 is rectangular, and has a plane dimension similar to that of the FPD mounted on the substrate mounting table 70. For example, the upper base material 71 has a plane dimension similar to that of the substrate G on which it is placed, the length of the long side is about 1800 mm to 3400 mm, and the length of the short side is about 1500 mm to 3000 mm. Can be set. With respect to this plane dimension, the total thickness of the upper base material 71 and the lower base material 72 can be, for example, about 50 mm to 100 mm.

The lower base material 72 is provided with a meandering temperature control medium flow path 72a so as to cover the entire region of the rectangular plane, and is formed of stainless steel, aluminum, an aluminum alloy, or the like. On the other hand, the upper base material 71 is also formed of stainless steel, aluminum, an aluminum alloy, or the like. The temperature control medium flow path 72a may be provided on, for example, the upper base material 71 or the electrostatic chuck 76. Further, the base material 73 may be formed of one member made of aluminum, an aluminum alloy, or the like, instead of a laminated body of two members as shown in the illustrated example.

A box-shaped pedestal 78 formed of an insulating material and having a step portion inside is fixed on the bottom plate 16 of the lower chamber 17, and a substrate mounting base 70 is placed on the step portion of the pedestal 78. To.

An electrostatic chuck 76 on which the substrate G is directly placed is formed on the upper surface of the upper base material 71. The electrostatic chuck 76 comprises a ceramic layer 74, which is a dielectric film formed by spraying ceramics such as alumina, and a conductive layer 75 (electrode) embedded inside the ceramic layer 74 and having an electrostatic adsorption function. Have.

The conductive layer 75 is connected to the DC power supply 85 via a feeder line 84. When a switch (not shown) interposed in the feeder line 84 is turned on by the control unit 90, a Coulomb force is generated by applying a DC voltage from the DC power supply 85 to the conductive layer 75. Due to this Coulomb force, the substrate G is electrostatically attracted to the upper surface of the electrostatic chuck 76, and is held in a state of being placed on the upper surface of the upper base material 71.

The lower base material 72 constituting the substrate mounting table 70 is provided with a meandering temperature control medium flow path 72a so as to cover the entire area of the rectangular plane. At both ends of the temperature control medium flow path 72a, a feed pipe 72b for supplying the temperature control medium to the temperature control medium flow path 72a and a temperature control medium that has been circulated through the temperature control medium flow path 72a to raise the temperature have been formed. It communicates with the discharged return pipe 72c.

As shown in FIG. 1, the feed pipe 72b and the return pipe 72c communicate with the feed flow path 87 and the return flow path 88, respectively, and the feed flow path 87 and the return flow path 88 communicate with the chiller 86, respectively. .. The chiller 86 has a main body that controls the temperature and discharge flow rate of the temperature control medium, and a pump that pumps the temperature control medium (neither is shown). A refrigerant is applied as the temperature control medium, and Garden (registered trademark), Fluorinert (registered trademark), and the like are applied to this refrigerant. The temperature control device 89 is composed of the feed flow path 87, the return flow path 88, and the chiller 86. The temperature control form of the illustrated example is a form in which the temperature control medium is circulated through the lower base material 72, but the lower base material 72 may have a built-in heater or the like and the temperature control may be performed by the heater. The temperature may be controlled by both the medium and the heater. Further, instead of the heater, the temperature control accompanied by heating may be performed by circulating a high temperature temperature control medium. The heater, which is a resistor, is formed of tungsten, molybdenum, or a compound of any one of these metals and alumina, titanium, or the like. Further, in the illustrated example, the temperature control medium flow path 72a is formed on the lower base material 72, but for example, the upper base material 71 or the electrostatic chuck 76 may have the temperature control medium flow path.

A temperature sensor such as a thermoelectric pair is arranged on the upper base material 71, and the monitor information by the temperature sensor is transmitted to the control unit 90 at any time. Then, the control unit 90 executes temperature control control of the upper base material 71 and the base material G based on the transmitted monitor information. More specifically, the control unit 90 adjusts the temperature and flow rate of the temperature control medium supplied from the chiller 86 to the feed flow path 87. Then, the temperature control medium whose temperature is adjusted and the flow rate is adjusted is circulated in the temperature control medium flow path 72a, so that the temperature control of the substrate mounting table 70 is executed. The temperature sensor such as a thermoelectric pair may be arranged on the lower base material 72 or the electrostatic chuck 76, for example.

A step portion is formed by the outer periphery of the electrostatic chuck 76 and the upper base material 71 and the upper surface of the rectangular member 78, and a rectangular frame-shaped focus ring 79 is placed on the step portion. When the focus ring 79 is installed on the step portion, the upper surface of the focus ring 79 is set to be lower than the upper surface of the electrostatic chuck 76. The focus ring 79 is formed of ceramics such as alumina or quartz.

A power feeding member 80 is connected to the lower surface of the lower base material 72. A feeder line 81 is connected to the lower end of the feeder member 80, and the feeder line 81 is connected to a high frequency power supply 83 which is a bias power supply via a matching box 82 that performs impedance matching. RF bias is generated by applying high-frequency power of, for example, 3.2 MHz from the high-frequency power supply 83 to the substrate mount 70, and the high-frequency power supply 59, which is the source source for plasma generation described below, generates RF bias. Ions can be attracted to the substrate G. Therefore, in the plasma etching process, both the etching rate and the etching selectivity can be increased. A through hole (not shown) may be provided in the lower base material 72, and the power feeding member 80 may penetrate the through hole and be connected to the lower surface of the upper base material 71. In this way, the substrate mounting table 70 forms a bias electrode on which the substrate G is placed to generate an RF bias. At this time, the portion of the chamber that becomes the ground potential functions as the counter electrode of the bias electrode, and constitutes a high-frequency power return circuit. The metal window 50 may be configured as a part of a high frequency power return circuit.

The metal window 50 is formed by a plurality of divided metal windows 57. The number of the divided metal windows 57 forming the metal window 50 (4 in the cross-sectional direction is shown in FIG. 1) can be set to various numbers such as 12 and 24.

Each of the divided metal windows 57 is insulated from the support frame 14 and the adjacent divided metal windows 57 by the insulating member 56. Here, the insulating member 56 is formed of a fluororesin such as PTFE (Polytetrafluoroethylene).

The split metal window 57 has a conductor plate 30 and a shower plate 40. Both the conductor plate 30 and the shower plate 40 are made of aluminum, an aluminum alloy, stainless steel, or the like, which are non-magnetic, conductive, and corrosion-resistant metals or metals with a corrosion-resistant surface treatment. There is. The surface treatment having corrosion resistance is, for example, anodizing treatment or ceramic spraying. Further, the lower surface of the shower plate 40 facing the treatment area S may be subjected to plasma resistance coating by anodizing treatment or ceramic spraying. The conductor plate 30 is grounded via a ground wire (not shown), and the shower plate 40 is also grounded via a conductor plate 30 joined to each other.

As shown in FIG. 1, a spacer (not shown) formed of an insulating member is disposed above each of the divided metal windows 57, and the high frequency antenna 54 is arranged separated from the conductor plate 30 by the spacer. It is installed. The high-frequency antenna 54 is formed by winding an antenna wire formed of a good conductive metal such as copper in an annular shape or a spiral shape. For example, a plurality of annular antenna wires may be arranged.

Further, a feeding member 57a extending above the upper chamber 13 is connected to the high frequency antenna 54, a feeding line 57b is connected to the upper end of the feeding member 57a, and the feeding line 57b is a matching device that performs impedance matching. It is connected to the high frequency power supply 59 via 58. An induced electric field is formed in the lower chamber 17 by applying high-frequency power of, for example, 13.56 MHz from the high-frequency power supply 59 to the high-frequency antenna 54. By this induced electric field, the processing gas supplied from the shower plate 40 to the processing region S is turned into plasma to generate inductively coupled plasma, and the ions in the plasma are provided to the substrate G. It should be noted that each divided metal window 57 may have its own high-frequency antenna, and control may be performed in which high-frequency power is individually applied to each high-frequency antenna.

The high-frequency power supply 59 is a source source for plasma generation, and the high-frequency power supply 83 connected to the substrate mounting table 70 is a bias source that attracts the generated ions and imparts kinetic energy. In this way, plasma is generated from the ion source source using inductive coupling, and a bias source, which is a separate power source, is connected to the substrate mounting table 70 to control the ion energy, thereby generating plasma and ion energy. Is controlled independently, and the degree of freedom of the process can be increased. The frequency of the high frequency power output from the high frequency power supply 59 is preferably set in the range of 0.1 to 500 MHz.

The metal window 50 is formed by a plurality of divided metal windows 57, and each divided metal window 57 is suspended from the top plate 12 of the upper chamber 13 by a plurality of suspenders (not shown). Since the high-frequency antenna 54 that contributes to the generation of plasma is arranged on the upper surface of the split metal window 57, the high-frequency antenna 54 is suspended from the top plate 12 via the split metal window 57.

A gas diffusion groove 32 is formed on the lower surface of the conductor plate main body 31 forming the conductor plate 30. The gas diffusion groove may be provided on the upper surface of the shower plate. Further, the shape forming the gas diffusion groove includes not only a concave shape formed in a long shape but also a concave shape formed in a planar shape.

The shower plate main body 41 forming the shower plate 40 is provided with a plurality of gas discharge holes 42 that penetrate the shower plate main body 41 and communicate with the gas diffusion groove 32 of the conductor plate 30 and the processing region S.

A plurality of supply ports 12a (four in the illustrated example) are provided on the top plate 12 of the upper chamber 13, and a gas introduction pipe 55 unique to each divided metal window 57 is airtightly provided to each supply port 12a. It penetrates. A branch pipe 69 constituting the gas supply device 60 described in detail below communicates with the gas introduction pipe 55. In the illustrated example, for example, the four branch pipes 69 communicate fluid with gas introduction pipes 55 unique to each, and the processing gas is supplied from the four gas introduction pipes 55 to each of the four divided metal windows 57. On the other hand, when the number of the divided metal windows 57 is three or less or five or more, any two of the four gas introduction pipes 55 are combined into one and fluid is communicated to one divided metal window 57. It may be in the form of Further, each of the four gas introduction pipes 55 may be branched into a plurality of parts in the antenna chamber A to communicate fluid with the five or more divided metal windows 57.

The gas supply device 60 includes a gas supply unit 61, a gas supply pipe 68 that communicates with the gas supply unit 61, and a branch pipe 69 that branches from the gas supply pipe 68 into four and communicates with the corresponding gas introduction pipe 55. Has. Various valves, sensors, and the like are interposed in the gas supply pipe 68 and the branch pipe 69 as described below.

In the plasma treatment, the processing gas supplied from the gas supply device 60 is supplied to the gas diffusion groove 32 of the conductor plate 30 of each of the divided metal windows 57 via the gas introduction pipe 55. Then, the gas is discharged from each gas diffusion groove 32 to the processing region S through the gas discharge hole 42 of each shower plate 40.

A gas flow rate control device 62 such as a mass flow controller (MFC) is arranged on the downstream side of the gas flow of the gas supply unit 61. Further, on the secondary side of the gas flow rate control device 62 (the downstream side of the gas flow, the downstream side with respect to the object is referred to as the secondary side. The same shall apply hereinafter), the gas on the downstream side. A first valve 63 for shutting off the gas flow to the supply pipe 68 is provided. Further, it is the secondary side of the first valve 63 and is the primary side of the branch pipe 69 (the upstream side of the gas flow, and the upstream side with respect to the object is referred to as the primary side. The same shall apply hereinafter). Is provided with a third valve 65. The form may not include the third valve 65.

In the gas supply pipe 68, a pressure sensor 64 such as a pressure switch is arranged between the first valve 63 and the third valve 65.

Gas diversion ratio control elements 66A, 66B, 66C, 66D such as FRC (Flow Ratio Controller) are arranged in each of the four branch pipes 69. The gas diversion ratio control elements 66A, 66B, 66C, and 66D all include a conductance variable flow path (not shown) in which the conductance can be changed. More specifically, it is equipped with a laminar flow element (bypass), a heat ray type sensor, a flow rate control bubble, an orifice, and the like (none of which are shown). Then, each gas diversion ratio control element 66A, 66B, 66C, 66D adjusts the opening degree of the unique orifice so that the diversion flow rate (splitting ratio) of the processing gas shunted into each branch pipe is adjusted. It has become. In each gas distribution ratio control element 66A, 66B, 66C, 66D, the processing gas is flowed to the secondary side due to the pressure difference (differential pressure) in the piping on the primary side and the secondary side.

In the illustrated example, the gas diversion ratio control unit 66 is configured by the four gas diversion ratio control elements 66A, 66B, 66C, 66D. In the gas diversion ratio control unit 66, the conductances of the plurality of gas diversion ratio control elements 66A, 66B, 66C, and 66D are variably controlled, so that the gas flow rate ratios supplied to the plurality of branch pipes 69 are controlled. To.

In each branch pipe 69, second valves 67A, 67B, 67C, 67D peculiar to each of the secondary side of the gas diversion ratio control elements 66A, 66B, 66C, 66D are arranged.

Processed gas diverted at a preset divergence ratio with respect to the divided metal window 57 unique to each via each branch pipe 69 interposed with four gas divergence ratio control elements 66A, 66B, 66C, 66D. Is supplied. Specifically, for example, it is a central processing area, an edge central portion of the outer peripheral processing area, a corner portion of the outer peripheral processing area, an intermediate processing area between the central processing area and the outer peripheral processing area, and the like. Each of the four gas introduction pipes 55 corresponds to each of the above four regions. The number of regions is not limited to four, and may be five, six, or more, if necessary. In that case, the number of corresponding gas introduction pipes 55 is also the corresponding number. That is, when there are five regions, the number of gas introduction pipes 55 is five, and when there are six regions, the number of gas introduction pipes 55 is six, and so on. This also applies to the gas diversion ratio control element 66 and the branch pipe 69 located on the upstream side of the gas introduction pipe 55. There may be a plurality of divided metal windows 57 that form each region. In that case, it branches from the gas introduction pipe 55 corresponding to each region and is connected to each of the plurality of divided metal windows 57. In this case, the distribution ratio of the processing gas supplied to each processing area is preset according to the recipe (process recipe). In the illustrated example, for the sake of brevity, the four divided metal windows 57 in the cross section of the apparatus correspond to the four regions of the processing region S.

In the illustrated example, the gas supply pipe 68 extends from one gas supply unit 61, branches in the middle of the gas supply pipe 68, and four branch pipes 69 extend, but other It may be in the form. For example, there is a mode in which unique gas supply pipes extend from a plurality of gas supply units, and each gas supply pipe is branched into a plurality of branches to include a plurality of branch pipes. From one gas supply unit 61, various treatment gases for performing various treatments such as film formation treatment and etching treatment are supplied to the gas supply pipe 68 as treatment gas. Further, in the form having a plurality of gas supply units, a plurality of types of processing gases for performing film formation treatment, etching treatment, etc. are supplied from each gas supply unit, and a film formation treatment, etc. is performed from one gas supply unit. There is also a form in which a processing gas for performing the above is supplied, and a carrier gas such as a rare gas is supplied from another gas supply unit. In addition to these, there is also a form in which oxygen gas or the like for controlling the depot of the reaction product is supplied from another gas supply unit, and in the present specification, these rare gases and oxygen gas and the like are also included in the processing gas. It shall be.

The control device 90 controls the operation of each component of the substrate processing device 100, for example, the chiller 86, the high-frequency power supplies 59 and 83, the gas supply device 60, and the gas exhaust unit 28 based on the monitor information transmitted from the pressure gauge. To do. The control device 90 includes a CPU (Central Processing Unit), a ROM (Read Only Memory), and a RAM (Random Access Memory). The CPU executes a predetermined process according to a recipe stored in a storage area of RAM or ROM. In the recipe, control information of the substrate processing apparatus 100 for the process conditions is set. The control information includes, for example, the gas flow rate, the pressure in the processing container 20, the temperature in the processing container 20, the temperature of the lower base material 72, the process time, and the like.

The recipe and the program applied by the control device 90 may be stored in, for example, a hard disk, a compact disk, a magneto-optical disk, or the like. Further, the recipe or the like may be set in the control unit 90 in a state of being housed in a storage medium that can be read by a portable computer such as a CD-ROM, a DVD, or a memory card, and may be read. The control unit 90 also has a user interface such as an input device such as a keyboard or mouse for inputting commands, a display device such as a display that visualizes and displays the operating status of the board processing device 100, and an output device such as a printer. Have.

Next, the gas supply method according to the first embodiment will be described.

As described above, the distribution ratio of the processing gas to each branch pipe 69 communicating with each divided metal window 57 corresponding to the plurality of regions (central region, peripheral region, etc.) of the processing region S is set according to the recipe. The distribution ratio for each recipe is stored in the control device 90.

In order to process the substrate G by supplying the processing gas from the gas supply unit 61 based on a certain recipe, the control device 90 first closes the second valves 67A, 67B, 67C, 67D of each branch pipe 69, and first. Control to open the valve 63 and the third valve 65 is executed.

By this control, the processing gas is supplied to the gas supply pipe 68, each branch pipe 69, and the gas distribution ratio control elements 66A, 66B, 66C, 66D on the secondary side of the gas flow rate control device 62 (gas supply pipe). And the process of supplying gas to the branch pipe and the gas diversion ratio control element). That is, by this step, prior to supplying the processing gas from the gas supply unit 61 to each processing region via the gas flow rate control device 62, the inside of the gas distribution ratio control elements 66A, 66B, 66C, 66D. The processing gas is supplied in advance.

Here, the effect of this step will be described with reference to FIG. In FIG. 2, when the control device 90 executes the processing gas supply start control to the gas flow rate control device 62 at time 0 seconds, the processing gas supply is started at time t1 (MFC gas discharge), and the time is changed. At t2, the regular MFC flow rate: Q1.

By the way, in a gas supply device in which there is a branch pipe in the middle of the gas supply pipe and the FRC is interposed in each branch pipe, even if the MFC flow rate is a normal flow rate, the FRC has a certain amount of processing gas. If it does not flow, the FRC cannot be controlled normally, and there is a problem that it is difficult for the processing gas having a normal flow rate to flow through each FRC. For this reason, it takes time from the start of gas ejection of the MFC to the flow of the processing gas at the normal flow rate through each FRC.

Since it is necessary for a certain flow rate of gas to flow through the FRC to start the FRC control, for example, as shown in FIG. 2, the processing gas starts to flow through the FRC at time t1, but the FRC flow rate (all FRC flow rates). The total flow rate of) gradually increases so as to gradually approach the normal processing flow rate of Q1 (see the dotted line graph). As a result, it takes time for the FRC flow rate to reach (or approach) Q1 which is the processing flow rate, and it also takes time to reach the flow rate at which individual FRCs can be controlled. Therefore, the start time of FRC control is time t3, and it takes a long time Δt1 from time 0 seconds (see the two-dot chain line graph). As a result, it takes time for the flow rate ratio of the processing gas supplied to the processing region S to stabilize.

Therefore, in the gas supply method according to the present embodiment, in the above-mentioned step of supplying gas to the gas supply pipe, the branch pipe, and the gas distribution ratio control element, the gas supply from the MFC is already started at 0 seconds. A processing gas having a flow rate of Q2 (<Q1) to some extent is circulated to the FRC in each branch pipe. By this step, the time until the FRC flow rate (total flow rate of all FRC flow rates) approaches the processing flow rate Q1 is significantly shortened (see the alternate long and short dash line graph). This reduces the time it takes to reach a flow rate that allows control of the individual FRCs. Therefore, as shown in FIG. 2, the start time of the FRC control is remarkably earlier from the time t3 to the time t4 (see the three-dot chain line graph). As a result, the flow rate ratio of the processing gas supplied to the processing region S becomes stable quickly.

In the above step, the pressure sensor 64 between the first valve 63 and the third valve 65 causes the pressure in the gas supply pipe 68 on the secondary side of the gas flow control device 62 or the gas diversion of the branch pipe 69 (gas diversion). The pressure of the ratio control elements 66A, 66B, 66C, 66D) is constantly measured. The measured measurement data is transmitted to the control device 90 at any time.

Data regarding the set pressure is stored in the control device 90. This set pressure is a pressure suitable for starting FRC control as early as possible, and for example, the set pressure can be set in the range of 50 Torr to 300 Torr (1 Torr = 133.4 Pa).

Then, when the control device 90 detects that the pressure by the pressure sensor 64 has reached the set pressure (the step of detecting that the set pressure has been reached), then the control device 90 detects that the pressure has reached the set pressure, and then the control device 90 detects that the pressure has reached the set pressure. The control to close the valve is executed (step of closing the first valve).

In this way, by closing the first valve 63 and the second valves 67A, 67B, 67C, 67D in each branch pipe 69, the pressure in the gas supply pipe 68 on the secondary side of the gas flow control device 62 and the pressure in the gas supply pipe 68 on the secondary side of the gas flow control device 62. The pressure in the branch pipe 69 (primary side of the gas diversion ratio control elements 66A, 66B, 66C, 66D) is maintained at the set pressure.

After that, the control device 90 executes control to open the first valve 63 and the second valves 67A, 67B, 67C, 67D at a timing preset according to the recipe, and the processing gas is processed via each branch pipe 69. Is supplied to the corresponding area in the processing area S (step of supplying gas to the processing container).

According to the substrate processing apparatus 100 and the gas supply method according to the present embodiment, when processing the substrate G, by supplying a certain amount of gas to the inside of the FRC in advance, the FRC reaches a normal flow rate. You can save time. As a result, the processing gas can be stably supplied to the processing region S in a short time. Also, if the same effect is obtained by optimizing the volume (length, thickness, etc.) of the gas supply pipe and branch pipe, the flow rate of the processing gas to be flowed differs depending on the application of the device. It is necessary to change various pipes to the optimum volume, but such hardware changes are unnecessary.

[Substrate processing apparatus and gas supply method according to the second embodiment]
Next, an example of the substrate processing apparatus and the gas supply method according to the second embodiment of the present disclosure will be described with reference to FIG. Here, FIG. 3 is a vertical cross-sectional view showing an example of the substrate processing apparatus according to the second embodiment.

The substrate processing device 100A is different from the substrate processing device 100 in that it has a main gas supply system for supplying the main gas and a gas supply device 60A having an assist gas supply system for supplying the assist gas.

Here, the main gas and the assist gas are treatment gases of the same type or different types, and both or one of them is a carrier of various treatment gases, rare gases, etc. for performing various treatments such as film formation treatment and etching treatment. Gas, oxygen gas that controls the depot of reaction products, etc. In the present specification, it is assumed that both are included in the processing gas, and the gas in which the main gas and the assist gas are mixed is also included in the processing gas.

The main gas supply system has a main gas supply unit 61A (gas supply unit) and a main gas supply pipe 68A (an example of a gas supply pipe) communicating with the main gas supply unit 61A. The main gas supply system further includes a main gas branch pipe 69A (an example of a branch pipe) that branches from the main gas supply pipe 68A into four and communicates with the corresponding gas introduction pipe 55.

A gas flow rate control device 62A (gas flow rate control device) for main gas is arranged on the secondary side of the main gas supply unit 61A, and a first valve 63A is provided on the secondary side of the gas flow rate control device 62A for main gas. It is arranged. Further, a third valve 65A is arranged on the secondary side of the first valve 63A and on the primary side of the main gas branch pipe 69A. Further, a pressure sensor 64A is arranged between the first valve 63A and the third valve 65A.

Gas diversion ratio control elements 66A, 66B, 66C, and 66D are arranged in each of the four main gas branch pipes 69A, respectively. Further, in each branch pipe 69A, second valves 67A, 67B, 67C, 67D peculiar to each of the secondary valves 67A, 67B, 67C, 67D are arranged on the secondary side of the gas diversion ratio control elements 66A, 66B, 66C, 66D.

On the other hand, the assist gas supply system has an assist gas supply unit 61B (gas supply unit) and an assist gas supply pipe 68B (an example of a gas supply pipe) communicating with the assist gas supply unit 61B. The assist gas supply system further includes an assist gas branch pipe 69B (an example of a branch pipe) that branches from the assist gas supply pipe 68B into four and communicates with the corresponding gas introduction pipe 55.

A gas flow rate control device 62B (gas flow rate control device) for assist gas is arranged on the secondary side of the assist gas supply unit 61B, and a first valve 63B is arranged on the secondary side of the gas flow rate control device 62B for assist gas. Are arranged. Further, a third valve 65B is arranged on the secondary side of the first valve 63B and on the primary side of the assist gas branch pipe 69B. Further, a pressure sensor 64B is arranged between the first valve 63B and the third valve 65B.

Gas diversion ratio control elements 66E, 66F, 66G, 66H are arranged in each of the four assist gas branch pipes 69B, respectively. Further, in each branch pipe 69B, second valves 67E, 67F, 67G, 67H peculiar to each are arranged on the secondary side of the gas diversion ratio control elements 66E, 66F, 66G, 66H, respectively.

The gas diversion ratio control unit 66 is configured by the eight gas diversion ratio control elements 66A, 66B, 66C, 66D, 66E, 66F, 66G, 66H.

On the secondary side of the second valves 67A, 67B, 67C, 67D in each main gas branch pipe 69A constituting the main gas supply system, the second valve 67E in each assist gas branch pipe 69B constituting the assist gas supply system. , 67F, 67G, 67H are in communication with each other.

In the gas supply method according to the second embodiment, the set pressure in the main gas supply system and the set pressure in the assist gas supply system may be the same pressure or different pressures, and both gases The content of control by the control device 90 for the supply system is the same as the gas supply method of the first embodiment.

That is, when both the main gas supply system and the assist gas supply system have a certain flow rate of processing gas flowed in advance to the gas distribution ratio control elements 66A to 66H and the pressure gauges 64A and 64B reach the set pressures, respectively. Close the first valves 63A and 63B. Then, by opening the first valves 63A and 63B and the second valves 67A to 67H according to the recipe, the main gas and the assist gas according to the diversion ratio are mixed on the secondary side of the second valves 67A to 67D. Four types of processing gas are generated. Each of the generated processing gas is supplied to the corresponding four regions in the processing region S via each branch pipe 69A. The area corresponding to the processing area S is not limited to four, as in the first embodiment, and there may be five, six, or more areas. In that case, the supply system of the main gas and the assist gas is also set according to the number of regions.

[Experiment to verify the time to stable supply of processed gas]
The present inventors manufactured the substrate processing apparatus shown in FIG. 3, changed each set pressure of the main gas supply system and the assist gas supply system in various ways, and measured the time until the stable supply of the processing gas (final convergence time). An experiment was conducted. Here, the final convergence time is the time until the difference ratio with the target gas flow rate becomes ± 2% or less.

In this experiment, the area where the processing gas is stored in advance is different. Specifically, in FIG. 3, the control in which the third valves 65A and 65B are closed and the processing gas is stored up to the primary side of the third valves 65A and 65B (the processing gas is not supplied to the FRC in advance) is compared. Examples 1 to 5 were set, and the control for supplying the processing gas to the FRC in advance was set to Examples 1 to 4. A conventional control method in which the processing gas is not supplied to the FRC in advance and the pressure in each supply system is zero is used as a reference example. Table 1 below shows reference examples, comparative examples, various conditions of each example, and experimental results.

From Table 1, it can be seen that the final convergence time of Comparative Examples 3 and 4 is longer than that of the reference example, and no effect is obtained.

On the other hand, it can be seen that the final convergence time of each example is shorter than that of the reference example. Above all, in Example 4 of 200 Torr in which the set pressures of the main gas supply system and the assist gas supply system are the same, the final convergence time is remarkably shortened to 20% or less, and the pressures in both supply piping systems are reduced. It has been proved that it is desirable to set it to about 200 Torr at the same level.

Other embodiments may be obtained in which other components are combined with respect to the configurations and the like described in the above embodiments, and the present disclosure is not limited to the configurations shown here. This point can be changed without departing from the gist of the present disclosure, and can be appropriately determined according to the application form thereof.

For example, the substrate processing devices 100 and 100A in the illustrated example have been described as an inductively coupled plasma processing device provided with a metal window, but may supply gas to a plurality of regions in the processing container at a preset flow rate ratio. As long as it has a configuration, it may be an inductively coupled plasma processing apparatus provided with a dielectric window instead of the metal window, or may be another form of plasma processing apparatus. Specific examples thereof include Electron Cyclotron resonance plasma (ECP), Helicon Wave Plasma (HWP), and Capacitively coupled Plasma (CCP). In addition, microwave-excited surface wave plasma (SWP) can be mentioned. All of these plasma processing devices, including ICP, can independently control the ion flux and ion energy, can freely control the etching shape and selectivity, and have a high electron density of about ^{10 11 to} 10 ¹³ cm ^-3. Is obtained.

20: Processing container 60, 60A: Gas supply device 61, 61A, 61B: Gas supply unit 62, 62A, 62B: Gas flow rate control device 63, 63A, 63B: First valve 66: Gas diversion ratio control unit 66A to 66H: Gas distribution ratio control element 67, 67A to 67H: Second valve 68, 68A, 68B: Gas supply pipe 69, 69A, 69B: Branch pipe G: Substrate

Claims (10)

A gas supply device for supplying gas to a processing container for processing a substrate, and at least one gas flow control device provided in a gas supply pipe leading from a gas supply unit to the processing container, and the gas flow control. It is composed of a gas diversion ratio control element provided with a conductance variable flow path having a variable conductance, which is provided in each of two or more branch pipes branching on the secondary side of the device, and two or more gas diversion ratio control elements. The gas divergence ratio control unit, the first valve and the pressure sensor on the secondary side of the gas flow control device and on the primary side of the gas divergence ratio control element, and the secondary side of the gas divergence ratio control element. In a gas supply device with a second valve on the side,
In processing the substrate, the second valve is closed, the first valve is opened, and the gas supply pipe, the branch pipe, and the gas distribution ratio control element on the secondary side of the gas flow rate control device are connected. The process of supplying gas and
A step of detecting that the pressure of the gas supply pipe or the branch pipe on the secondary side of the gas flow rate control device has reached a set pressure by the pressure sensor.
The process of closing the first valve and
A gas supply method comprising a step of opening the first valve and the second valve to supply the gas to the processing container. The gas flow rate control unit according to claim 1, wherein the gas flow rate control unit controls the gas flow rate ratio to be supplied to each of the plurality of branch pipes by variably controlling the conductance of each of the plurality of gas split ratio control elements. Gas supply method. The first or second aspect of the present invention, wherein the plurality of branch pipes communicate with each other in the corresponding processing area of the processing container, and supply the gas flowing through the branch pipes to the corresponding processing area. Gas supply method. The gas has a main gas and an assist gas.
The gas supply unit has a main gas supply unit and an assist gas supply unit.
The gas flow rate control device includes a gas flow rate control device for main gas and a gas flow rate control device for assist gas.
The gas supply pipe has a main gas supply pipe through which the main gas flows and an assist gas supply pipe through which the assist gas flows.
The branch pipe has a main gas branch pipe through which the main gas flows and an assist gas branch pipe through which the assist gas flows.
The secondary side of the second valve of the main gas branch pipe communicates with the secondary side of the second valve of the corresponding assist gas branch pipe.
The gas according to claim 3, wherein the assist gas is supplied to the main gas to generate two or more processing gases, and the two or more processing gases are supplied to the corresponding processing regions of the processing container, respectively. Supply method. While detecting that the pressure of the main gas supply pipe or the main gas branch pipe on the secondary side of the main gas gas flow control device has reached the set pressure, the assist gas gas flow control device It is detected that the pressure of the assist gas supply pipe or the assist gas branch pipe on the secondary side of the above reaches the set pressure, and after both of the pressures reach the set pressure, the main gas is used. Close each of the first valves on the secondary side of the gas flow control device and the gas flow control device for assist gas.
The gas supply method according to claim 4, wherein both the first valve and both second valves are opened to generate the processing gas. A substrate processing apparatus provided with a gas supply device for supplying gas to a processing container for processing a substrate.
At least one gas flow rate control device provided in the gas supply pipe leading from the gas supply unit to the processing container, and
Gas flow rate control composed of gas flow rate control elements provided with a conductance variable flow path that can change the conductance, which are provided in each of two or more branch pipes that branch on the secondary side of the gas flow rate control device. Department and
The first valve and pressure sensor on the secondary side of the gas flow rate control device and on the primary side of the gas flow rate control element,
The second valve on the secondary side of the gas diversion ratio control element,
With a control device,
The control device is
In processing the substrate, the second valve is closed, the first valve is opened, and the gas supply pipe, the branch pipe, and the gas distribution ratio control element on the secondary side of the gas flow rate control device are connected. Perform control to supply gas,
After the pressure sensor detects that the pressure of the gas supply pipe or the branch pipe on the secondary side of the gas flow rate control device has reached the set pressure, the control for closing the first valve is executed.
A substrate processing apparatus that opens the first valve and the second valve to control the supply of the gas to the processing container. The control device variably controls the conductance of each of the plurality of gas divergence ratio control elements with respect to the gas divergence ratio control unit, and controls the gas flow rate ratio supplied to each of the plurality of branch pipes. The substrate processing apparatus according to claim 6. Each of the plurality of branch pipes communicates with the corresponding processing area of the processing container.
The substrate processing apparatus according to claim 6 or 7, wherein the gas flowing through each of the branch pipes is supplied to the corresponding processing area. The gas has a main gas and an assist gas.
The gas supply unit has a main gas supply unit and an assist gas supply unit.
The gas flow rate control device includes a gas flow rate control device for main gas and a gas flow rate control device for assist gas.
The gas supply pipe has a main gas supply pipe through which the main gas flows and an assist gas supply pipe through which the assist gas flows.
The branch pipe has a main gas branch pipe through which the main gas flows and an assist gas branch pipe through which the assist gas flows.
The secondary side of the second valve of the main gas branch pipe communicates with the secondary side of the second valve of the corresponding assist gas branch pipe.
The eighth aspect of the present invention, wherein the assist gas is supplied to the main gas to generate two or more processing gases, and the two or more processing gases are supplied to the corresponding processing regions of the processing container, respectively. Substrate processing equipment. The control device is
The pressure sensor detects that the pressure of the main gas supply pipe or the main gas branch pipe on the secondary side of the main gas flow control device has reached the set pressure, and the assist gas. After detecting that the pressure of the assist gas supply pipe or the assist gas branch pipe on the secondary side of the gas flow control device has reached the set pressure, the main gas gas flow control device and the assist A control for closing the first valve of both gas flow control devices for gas is executed, and then a control for opening both the first valve and the second valve of both is executed to generate the processing gas. Item 9. The substrate processing apparatus according to Item 9.

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