Substrate processing apparatus and substrate processing method

Abstract

To suppress a reverse flow of one of two types of gases supplied separately to a processing space from a shower head to a gas diffusion chamber of the other gas.SOLUTION: A plasma processing device comprises: a processing container which includes a processing space; a shower head which supplies a first gas and a second gas independently to the processing space; and a control unit. The shower head comprises: first and second gas diffusion chambers 101, 102 which diffuse the first gas and the second gas; first and second openings 111, 112 which eject the first and second gases; and first and second gas supply paths 121, 122 which make the first and second gas diffusion chambers respectively communicate to the first and second openings. The control unit performs control such that a pressure difference between the first gas diffusion chamber and the processing space is equal to or greater than 47 Pa, and a gas flow rate per one first gas supply path is equal to or greater than 0.15 sccm. A bottle neck 121a is provided in at least a portion of the first gas supply path, and an aspect ratio of a length to a thickness of the bottle neck is equal to or greater than 10.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present disclosure relates to a substrate processing apparatus and a substrate processing method.

Background Art

[0002] In Patent Document 1, a workpiece having a silicon oxide film formed on its surface is placed on a mounting table in a chamber, and an HF gas and an NH3 gas, which are reaction gases, are discharged from a plurality of gas discharge holes of a shower plate provided above the mounting table so as to correspond to the workpiece placed on the mounting table. Then, a process of reacting these gases with the silicon oxide film on the surface of the non-processed body is performed, and then etching is performed by heating and decomposing the reaction product generated by this reaction to remove it. Further, the shower head of Patent Document 1 has a shower plate, and discharges HF gas from a plurality of first gas discharge holes provided in the shower plate, and discharges NH3 gas from a plurality of second discharge holes provided in the shower plate.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] The technology according to the present disclosure suppresses one of two types of gases separately supplied from a shower head to a processing space from flowing back into the gas diffusion chamber of the other gas in the shower head and being mixed when using a shower head in which gas diffusion chambers for each gas type are stacked.

Means for Solving the Problems

[0005] One aspect of the present disclosure is a substrate processing apparatus that performs processing on a substrate with a first gas and a second gas, A processing container having an internal processing space where the processing is performed on the substrate, a shower head that independently supplies the first gas and the second gas to the processing space, and a control unit, wherein the shower head has, inside, a first gas diffusion chamber that diffuses the first gas and a second gas diffusion chamber that is disposed below the first gas diffusion chamber and diffuses the second gas, and has, on the lower surface, a plurality of first openings that eject the first gas and a plurality of second openings that eject the second gas, and a plurality of first gas supply paths that communicate the first gas diffusion chamber with the plurality of first openings and a plurality of second gas supply paths that communicate the second gas diffusion chamber with the plurality of second openings, and the control unit performs control such that the pressure difference between the first gas diffusion chamber and the processing space is 47 Pa or more and the gas flow rate per one of the plurality of first gas supply paths is 0.15 sccm or more, and at least a part of each of the first gas supply paths is provided with a constriction, and the aspect ratio of the length to the width of the constriction is 10 or more.

Advantages of the Invention

[0006] According to the present disclosure, when using a shower head in which gas diffusion chambers for each gas type are stacked, it is possible to suppress one of two types of gases independently supplied from the shower head to the processing space from flowing backward into the gas diffusion chamber of the other gas in the shower head and being mixed.

Brief Description of the Drawings

[0007]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Embodiment for Carrying Out the Invention

[0008] In the manufacturing process of a flat panel display (FPD) such as a liquid crystal display device (LCD), processes such as an etching process and a film forming process are performed on a substrate such as a glass substrate by a substrate processing apparatus.

[0009] The substrate processing apparatus includes a processing container that houses a substrate to be processed, and a shower head that supplies a processing gas to a processing space in the processing container. In a process that requires multiple types of gases, a post-mix method is often used in which the multiple types of gases are supplied separately from the shower head and mixed in the processing chamber without being mixed in the shower head. The post-mix method is used, for example, when the gases used in the process are a combustible gas and a supporting combustion gas and there is a risk of explosion or the like if they are mixed in the shower head.

[0010] Further, in the post-mix method, as the shower head, one having a multi-stage structure in which one gas diffusion chamber that diffuses one gas in the horizontal direction and another gas diffusion chamber that diffuses another gas in the horizontal direction are stacked in the vertical direction may be used. In this shower head, one ejection hole that ejects one gas in one gas diffusion chamber into the processing space and another ejection hole that ejects another gas in another gas diffusion chamber into the processing space are individually provided on the lower surface of the shower head.

[0011] However, when a shower head having a multi-stage structure is used, there is a possibility that one gas ejected into the processing space from the ejection hole for one gas may flow back through the gas ejection hole for the other gas and be mixed with the other gas in the shower head.

[0012] Therefore, in the case of using a showerhead in which gas diffusion chambers for each gas type are stacked, the technology according to the present disclosure suppresses one of two types of gases independently supplied from the showerhead to the processing space from flowing backward and mixing into the gas diffusion chamber of the other gas in the showerhead.

[0013] Hereinafter, the substrate processing apparatus and the substrate processing method according to the present embodiment will be described with reference to the drawings. In the present specification and the drawings, elements having substantially the same functional configuration are denoted by the same reference numerals, and redundant descriptions are omitted.

[0014] <Plasma processing apparatus 1> FIG. 1 is a longitudinal sectional view showing an outline of the configuration of a plasma processing apparatus as a substrate processing apparatus according to the present embodiment.

[0015] The plasma processing apparatus 1 in FIG. 1 performs processing on a rectangular glass substrate G (hereinafter referred to as "substrate G") as a substrate using two types of processing gases. More specifically, the plasma processing apparatus 1 performs plasma processing using the plasma of two types of processing gases on the substrate G as processing. In the present embodiment, the plasma processing performed by the plasma processing apparatus 1 is a film forming process for FPD. However, the plasma processing performed by the plasma processing apparatus 1 may be an etching process, an ashing process, etc. for FPD. By the plasma processing performed by the plasma processing apparatus 1, electronic devices such as light emitting elements and drive circuits of light emitting elements are formed on the substrate G.

[0016] The plasma processing apparatus 1 includes a container body 10 having a rectangular tube shape. The container body 10 is formed of a conductive material, such as aluminum, and is electrically grounded. When a gas corrosive to plasma processing is used, the inner wall surface of the container body 10 is subjected to a corrosion-resistant coating treatment, such as anodic oxidation treatment, for the purpose of improving corrosion resistance. An opening is formed on the upper surface of the container body 10. This opening is hermetically sealed by a rectangular metal window 20 provided in insulation from the container body 10. Specifically, it is hermetically sealed by the metal window 20 and a metal frame 14 described later. The space surrounded by the container body 10 and the metal window 20 becomes a processing space S1 where processing (specifically, plasma processing) is performed on the substrate G, and the space above the metal window 20 becomes an antenna chamber S2 where a high-frequency antenna (inductive coupling antenna) 80 described later is disposed. On the side wall of the container body 10, a loading / unloading port 11 for loading / unloading the substrate G into / from the processing space S1 and a gate valve 12 for opening / closing the loading / unloading port 11 are provided.

[0017] A substrate support portion 30 for supporting the substrate G is provided on the lower side of the processing space S1 so as to face the metal window 20. The substrate support portion 30 has a main body portion 31 on which the substrate G is placed, and the main body portion 31 is installed on the bottom surface of the container body 10 via legs 32.

[0018] The main body portion 31 is made of a conductive material, such as aluminum. The surface of the main body portion 31 is subjected to a coating treatment, such as anodic oxidation treatment or ceramic spraying treatment, to improve the emissivity of the surface.

[0019] Also, if necessary, a high-frequency power source for bias may be connected to the main body portion 31.

[0020] An exhaust port 13 is formed on the bottom surface of the container body 10, and an exhaust portion 50 having a vacuum pump or the like is connected to this exhaust port 13. The processing space S1 is depressurized by this exhaust portion 50. The exhaust portion 50 may be provided for each of the plurality of exhaust ports 13, or may be provided in common for the plurality of exhaust ports 13.

[0021] On the upper surface side of the side wall of the container body 10, a metal frame 14, which is a rectangular frame made of a metal material such as aluminum, is provided. A seal member (not shown) for keeping the processing space S1 airtight is provided between the container body 10 and the metal frame 14. Further, the container body 10, the metal frame 14, and the metal window 20 constitute a processing container having the processing space S1 inside.

[0022] The metal window 20 is divided into a plurality of partial windows 21, and these partial windows 21 are arranged inside the metal frame 14 to form a rectangular metal window 20 as a whole. The shapes of the partial windows 21 in plan view are not common. For example, there are those having a quadrangular shape (e.g., trapezoidal) in plan view and those having a triangular shape in plan view.

[0023] Each of the partial windows 21 is a shower head configured to be able to independently supply a first processing gas and a second processing gas to the processing space S1 at the same time. The first processing gas is, for example, a combustible gas, and in this embodiment, it is SiH4 gas. The second processing gas is, for example, a supporting combustion gas (specifically, an oxidizing gas), and in this embodiment, it is O2 gas.

[0024] The partial window 21 adjacent to the metal frame 14 is electrically insulated from the metal frame 14 by an insulating member 22, and the adjacent partial windows 21 are also electrically insulated from each other by the insulating member 22. An insulating member cover 23 that covers the surface of the insulating member 22 on the processing space S1 side is provided on the insulating member 22 to protect the insulating member 22. Further, each partial window 21 is suspended and held from the ceiling surface side of the antenna chamber S2 via a holding portion (not shown). Details of the structure of the partial window 21 will be described later.

[0025] Furthermore, each partial window 21 is connected to a first gas source 61 via a first supply pipe 60. Specifically, an inlet 131 (see FIG. 2 described later) of each partial window 21 is connected to the first gas source 61 via the first supply pipe 60. A first supply mechanism 62 is interposed in the first supply pipe 60. The first supply mechanism 62 includes an on-off valve 62a and a flow rate adjustment valve 62b, and supplies the first processing gas from the first gas source 61 to the partial window 21 after adjusting the flow rate.

[0026] Also, each partial window 21 is connected to a second gas source 64 via a second supply pipe 63. Specifically, an inlet 132 (see FIG. 2 described later) of each partial window 21 is connected to the second gas source 64 via the second supply pipe 63. A second supply mechanism 65 is interposed in the second supply pipe 63. The second supply mechanism 65 includes an on-off valve 65a and a flow rate adjustment valve 65b, and supplies the second processing gas from the second gas source 64 to the partial window 21 after adjusting the flow rate.

[0027] For the sake of illustration, the figure shows a state where only the first supply pipe 60 and the second supply pipe 63 are connected to one partial window 21, but actually, the first supply pipe 60 and the second supply pipe 63 are connected to each partial window 21.

[0028] Furthermore, a top plate portion 70 is disposed above the metal window 20. The top plate portion 70 is supported by a side wall portion 71 provided on the metal frame 14.

[0029] The space surrounded by the above-described metal window 20, side wall portion 71, and top plate portion 70 constitutes an antenna chamber S2, and a high-frequency antenna 80 is disposed inside the antenna chamber S2 so as to face the partial window 21.

[0030] The high-frequency antenna 80 is disposed at a distance from the partial window 21 via a spacer (not shown) formed of, for example, an insulating material. The high-frequency antenna 80 is formed in a plurality of concentric and spiral shapes, for example, so as to surround along the circumferential direction of the rectangular metal window 20 along the surface corresponding to each partial window 21, thereby constituting a multi-loop antenna.

[0031] Each high-frequency antenna 80 is connected to a high-frequency power supply 41 as a plasma generation means via a matching unit 40. To each high-frequency antenna 80, high-frequency power of, for example, 13.56 MHz is supplied from the high-frequency power supply 41 via the matching unit 40. As a result, during plasma processing, eddy currents that circulate from the upper surface to the lower surface of each surface of the partial window 21 are induced, and an induced electric field is formed inside the processing space S1 by the current flowing to the lower surface among these eddy currents. The processing gas supplied from the partial window 21 is plasmaized inside the processing space S1 by the induced electric field.

[0032] Furthermore, the plasma processing apparatus 1 is provided with a pressure gauge 90 for measuring the pressure in the processing space S1.

[0033] The plasma processing apparatus 1 is also provided with a control unit U. The control unit U is a computer including a processor such as a CPU and a memory, etc., and has a program storage unit (not shown). A program for controlling the processing of the substrate G in the plasma processing apparatus 1 is stored in the program storage unit. The above-mentioned program may be recorded on a computer-readable storage medium and installed from the storage medium to the control unit U. Part or all of the program may be realized by dedicated hardware (circuit board).

[0034] <Partial window 21> FIG. 2 is a longitudinal sectional view showing an outline of the configuration of the partial window 21. FIGS. 3 to 5 are respectively bottom views of the first to third plates described later. As shown in FIG. 2, each partial window 21 has a first gas diffusion chamber 101 and a second gas diffusion chamber 102 inside, and a plurality of first openings 111 and a plurality of second openings 112 at the lower end.

[0035] The first gas diffusion chamber 101 diffuses the first processing gas (SiH4 gas in this embodiment) in the horizontal direction. The second gas diffusion chamber 102 is disposed below the first gas diffusion chamber 101 and diffuses the second processing gas (O2 gas in this embodiment) in the horizontal direction. Each of the first openings 111 ejects the first processing gas in the first gas diffusion chamber 101 into the processing space S1. Each of the second openings 112 ejects the second processing gas in the second gas diffusion chamber 102 into the processing space S1.

[0036] Further, each partial window 21 further has a plurality of first gas supply paths 121 and a plurality of second gas supply paths 122.

[0037] The plurality of first gas supply paths 121 communicate the first gas diffusion chamber 101 with the plurality of first openings 111. That is, each of the first gas supply paths 121 communicates the corresponding first opening 111 with the first gas diffusion chamber 101. Each of the first gas supply paths 121 passes through the second gas diffusion chamber 102. When passing through, the first gas supply path 121 and the second gas diffusion chamber 102 are separated by, for example, the pipe wall of the guiding pipe 222 described later so that the second processing gas in the second gas diffusion chamber 102 does not mix into the first gas supply path 121. In addition, a constriction 121a (that is, a portion narrower than other portions in the first gas supply path 121) is formed in at least a part of each of the first gas supply paths 121.

[0038] The plurality of second gas supply paths 122 communicate the second gas diffusion chamber 102 with the plurality of second openings 112. That is, each of the second gas supply paths 122 communicates the corresponding second opening 112 with the second gas diffusion chamber 102.

[0039] Specifically, the partial window 21 has a configuration in which a first plate 201, a second plate 202, and a third plate 203 are stacked in this order from above.

[0040] As shown in FIGS. 2 and 3, one recess 211 is formed on the lower surface of the first plate 201, and the first gas diffusion chamber 101 is formed by closing the recess 211 with the second plate 202. Similarly, as shown in FIGS. 2 and 4, one recess 221 is formed on the lower surface of the second plate 202, and the second gas diffusion chamber 102 is formed by closing the recess 221 with the third plate 203.

[0041] Further, on the upper surface of the first plate 201, as shown in FIG. 2, an inlet 131 for the first processing gas and an inlet 132 for the second processing gas are formed.

[0042] The inlet 131 communicates with the first gas diffusion chamber 101 via the first gas introduction path 141. The first gas introduction path 141 is formed so as to extend in the vertical direction and penetrate the first plate 201. In the example of the figure, the number of inlets 131 is one, but it may be two or more.

[0043] The inlet 132 communicates with the second gas diffusion chamber 102 via the second gas introduction path 142. The second gas introduction path 142 is formed so as to extend in the vertical direction. Further, the second gas introduction path 142 is formed so as to straddle the first plate 201 and the second plate 202 and pass through the first gas diffusion chamber 101. In the portion of the second gas introduction path 142 passing through the first gas diffusion chamber 101, a conduit 212 forming the second gas introduction path 142 is provided in its hollow portion. Thereby, the first processing gas in the first gas diffusion chamber 101 is prevented from mixing into the second gas introduction path 142. The conduit 212 is provided so as to penetrate the first gas diffusion chamber 101 in the vertical direction.

[0044] In the example of the figure, the number of inlets 132 and conduits 212 is one, but it may be two or more.

[0045] Further, each of the plurality of first gas supply paths 121 and the plurality of second gas supply paths 122 described above is also formed so as to extend in the vertical direction.

[0046] Each of the first gas supply paths 121 is formed so as to straddle the second plate 202 and the third plate 203 and pass through the second gas diffusion chamber 102. In the portion of the first gas supply path 121 that passes through the second gas diffusion chamber 102, a conduit 222 whose hollow portion forms the first gas supply path 121 is provided. The conduit 222 is provided so as to vertically penetrate the second gas diffusion chamber 102. In the present embodiment, the conduit 222 is formed so as to protrude from the lower surface of the second plate 202, but a part or all of it may be formed so as to protrude from the upper surface of the third plate 203. Also, in the example of the figure, the above-described constriction 121a is formed inside the conduit 222. However, a part or all of the constriction 121a may be formed outside the conduit 222.

[0047] Each of the second gas supply paths 122 is formed so as to penetrate the third plate 203.

[0048] Also, as shown in FIG. 5, the plurality of first openings 111 and the plurality of second openings 112 described above are arranged in a staggered pattern on the lower surface of the third plate 203.

[0049] Note that the number of conduits 212 is less than the number of conduits 222. As a result, the first gas diffusion chamber 101 is larger than the second gas diffusion chamber 102. The SiH4 gas, which is the first processing gas, is less likely to diffuse than the O2 gas, which is the second processing gas, because the supply flow rate to each partial window 21 during plasma processing is low. However, in the present embodiment, since the first gas diffusion chamber 101 for diffusing the first processing gas is larger than the second gas diffusion chamber 102 as described above, the first processing gas can be diffused in the same manner as the second processing gas even if the supply flow rate is low.

[0050] The first to third plates 201 to 203 are each made of, for example, a non-magnetic and conductive material (such as aluminum). When a corrosive gas is used as the first processing gas, the following parts that come into contact with the first processing gas may be coated with a corrosion-resistant coating such as an anodizing treatment to improve corrosion resistance. That is, · The surface forming the first gas introduction path 141 of the first plate 201, · The surfaces of the first plate 201 and the second plate 202 that form the first gas diffusion chamber 101, · The surfaces of the second plate 202 and the third plate 203 that form the first gas supply path 121, · The lower surface, which is the surface on the processing space S1 side of the third plate 203 may be coated with a corrosion-resistant coating. Further, the lower surface of the third plate 203 is coated with a plasma-resistant coating such as a treatment of coating with a ceramic such as yttrium oxide to improve plasma resistance.

[0051] Also, at least a part of the above-mentioned parts that come into contact with the first processing gas may be composed of stainless steel parts.

[0052] The second plate 202 is fastened to the first plate 201 by fastening screws (not shown), and the third plate 203 is also fastened to the second plate 202 by fastening screws (not shown).

[0053] Also, O-rings (not shown) for sealing the first processing gas and the second processing gas are provided at the portions where the first plate 201 and the second plate 202 contact each other and at the portions where the second plate 202 and the third plate 203 contact each other.

[0054] FIG. 6 is a diagram for explaining the dimensions of the constriction 121a of the first gas supply path 121. As described above, a constriction 121a is formed in the first gas supply path 121. By increasing the aspect ratio (L1 / R1) of the length L1 to the thickness (specifically, the diameter) R1 of the constriction 121a, it is possible to suppress the second processing gas ejected from the second opening 112 from flowing backward through the first gas supply path 121 including the constriction 121a and mixing into the first gas diffusion chamber 101. In the present embodiment, the aspect ratio is 10 or more. Note that, from the viewpoint of suppressing an increase in the size of the apparatus, etc., it is difficult to increase the aspect ratio by adjusting the length L of the constriction 121a. Therefore, the aspect ratio is set to 10 or more by narrowing the diameter R1 of the constriction 121a.

[0055] In the present embodiment, a constriction 122a is also formed at the lower end of the second gas supply path 122. Regarding the constriction 122a, the aspect ratio (L2 / R2) of the length L2 to the thickness R2 may also be set to 10 or more.

[0056] <Substrate processing> Next, the substrate processing in the plasma processing apparatus 1 will be described. First, under the control of the control unit U, the gate valve 12 is opened, and the substrate G is carried into the processing space S1 through the carry-in outlet 11 and placed on the substrate support unit 30. Thereafter, the gate valve 12 is closed.

[0057] Subsequently, under the control of the control unit U, SiH4 gas as the first processing gas and O2 gas as the second processing gas are simultaneously and individually supplied into the processing space S1 from the first and second openings 111 and 112 of each partial window 21, respectively. Further, the processing space S1 is exhausted by the exhaust unit 50, and the inside of the processing space S1 is adjusted to a desired pressure. At this time, the control unit U performs control so as to satisfy the following conditions (1) to (3). Specifically, based on the measurement results of the pressure gauge 90 and the like so as to satisfy the following conditions (1) to (3), the first supply mechanism 62, the second supply mechanism 65, and the exhaust unit 50 are controlled.

[0058] (1) The pressure difference between the first gas diffusion chamber 101 and the processing space S1 is 47 Pa or more. (2) The gas flow rate per one of the plurality of first gas supply paths 121 is higher than the gas flow rate per one of the plurality of second gas supply paths 122. (3) The gas flow rate per one of the plurality of first gas supply paths 121 is 0.15 sccm or more.

[0059] Also, in order to satisfy the above (1), the control unit U performs control so as to satisfy the following condition (4). Specifically, the first supply mechanism 62, the second supply mechanism 65, and the exhaust unit 50 are controlled so as to satisfy the following condition (4). (4) The pressure in the processing space S1 is 1 Pa to 5 Pa (preferably 1.3 to 4.0 Pa).

[0060] Next, under the control of the control unit U, a film forming process is performed on the substrate G as a process. Specifically, under the control of the control unit U, high-frequency power is supplied from the high-frequency power supply 41 to the high-frequency antenna 80, and as a result, an induced electric field is generated in the processing space S1 through the metal window 20. As a result, the SiH4 gas and the O2 gas in the processing space S1 are plasmaized by the induced electric field, a high-density inductively coupled plasma is generated, and a SiO film is formed on the substrate G. During the film formation of the SiO film by this plasma, the control unit U performs control so as to satisfy the above conditions (1) to (3).

[0061] After the film formation is completed, under the control of the control unit U, the power supply from the high-frequency power supply 41 and the supply of the processing gas through the partial window 21 are stopped, and the SiH4 gas and the O2 gas are discharged from the processing space S1 by the exhaust unit 50. Then, the substrate G is carried out in the reverse order from when it was carried in. Thereby, a series of substrate processes is completed.

[0062] <Simulation> The inventors simulated the ratio of the O2 gas among the SiH4 gas and O2 gas independently supplied from the partial window 21 configured as described above into the processing space S1 that flows backward into the first gas diffusion chamber 101 within the partial window 21 and is mixed with the SiH4 gas, that is, the reverse diffusion of the O2 gas. The results are shown in FIGS. 7 to 9. In the following simulations A to C, it is common that the number of the first gas supply path 121 and the second gas supply path 122 is one each, and the diameter R2 of the constriction 122a of the second gas supply path 122 is 1 mm and the length L2 is 5 mm.

[0063] (Simulation A) In simulation A, the influence of the flow rate of the SiH4 gas, which is the first processing gas, on the reverse diffusion of the O2 gas, which is the second processing gas, was verified. In simulation A, the flow rate ratio of the SiH4 gas to the O2 gas was fixed at 1:10, the diameter R1 of the constriction 121a of the first gas supply path 121 was 0.8 mm, the length L1 was 8 mm, and the aspect ratio was 10.

[0064] As shown in FIG. 7, according to simulation A, even when the flow rate ratio of the SiH4 gas to the O2 gas is the same at 1:10, the greater the flow rate of the SiH4 gas, the greater the differential pressure with the processing space S1 of the first gas diffusion chamber 101. Also, the greater the flow rate of the SiH4 gas, the lower the upper-stage mixing rate, that is, the mixing rate of the O2 gas into the first gas diffusion chamber 101. Specifically, when the flow rate of the SiH4 gas is 0.2 sccm or more, the differential pressure exceeds 46.7 Pa and the upper-stage mixing rate is lower than the target value of 2%, whereas when the flow rate of the SiH4 gas is as low as 0.1 sccm, the differential pressure is as low as about 34.5 and the upper-stage mixing rate greatly exceeds the target value of 2.0%. The lower-stage mixing rate, that is, the mixing rate of the SiH4 gas into the second gas diffusion chamber 102, was 0% regardless of the flow rate of the SiH4 gas.

[0065] (Simulation B) In Simulation B, when the flow rate ratio of SiH4 gas to O2 gas is 1:10, the flow rate of SiH4 gas is as low as 0.1 sccm, and the upper-stage mixing rate is high, it was verified whether the upper-stage mixing rate could be improved by increasing the aspect ratio of the constriction 121a of the first gas supply passage 121. Further, in Simulation B, the length L1 of the constriction 121a was fixed at 8 mm.

[0066] As shown in FIG. 8, according to Simulation B, by increasing the aspect ratio of the constriction 121a, the differential pressure with the processing space S1 of the first gas diffusion chamber 101 increased, and the upper-stage mixing rate decreased. Specifically, when the aspect ratio was 27, the upper-stage mixing rate was 1 / 4.4 compared to the case where the aspect ratio was 10. This is because the differential pressure at both ends of the constriction 121a increases as the aspect ratio increases. However, the upper-stage mixing rate still exceeded 2%.

[0067] Also, according to the results of Simulations A and B, it is speculated that the flow rate of SiH4 gas has a greater impact on the upper-stage mixing rate than the aspect ratio of the constriction 121a. Note that the lower-stage mixing rate was 0% regardless of the aspect ratio of the constriction 121a.

[0068] (Simulation C) Therefore, in Simulation C, the change in the upper-stage mixing rate was verified when only the flow rate of SiH4 gas was changed without changing the flow rate of O2 gas. In this Simulation C, the flow rate of O2 gas was 1 sccm, the diameter R1 of the constriction 121a of the first gas supply passage 121 was 0.3 mm, the length L1 was 8 mm, and the aspect ratio was fixed at 27. As shown in FIG. 9, according to Simulation C, by increasing the flow rate of SiH4 gas from 0.1 sccm to 0.15 sccm without changing the flow rate of O2 gas, the differential pressure with the processing space S1 of the first gas diffusion chamber 101 increased, and the upper-stage mixing rate was 2.0% or less, and further fell below the higher target value of 1.0%, specifically down to 0.40%.

[0069] Also, according to Simulations A to C, when the flow rate of SiH4 gas is 0.15 sccm, even when the aspect ratio of the constriction 121a is 10, although the differential pressure in the first gas diffusion chamber 101 does not exceed 47 Pa, the upper-stage mixing ratio is approximately 1.76% (0.4×10.2 / 2.3), and it is presumed that this will be equal to or less than the target value of 2.0%. The above estimated value is calculated by comparing the results for the case where the aspect ratio of Simulation B is 10 and 27, and the results for the case where the flow rate of SiH4 gas in Simulation C is 0.15 sccm. Note that the lower-stage mixing ratio was 0% regardless of the flow rate of SiH4 gas.

[0070] (Other Simulations) In addition, the inventors verified the influence of the aspect ratio of the constriction 121a on the upper-stage mixing ratio when N2 gas was used instead of O2 gas as the second processing gas, the flow rate of N2 gas was set to 3.8 sccm, and the flow rate of SiH4 gas was increased to 0.4 sccm. In this simulation, since the flow rate of SiH4 gas is quite high at 0.4 sccm, it is predicted that even if the aspect ratio of the constriction 121a is small, the differential pressure with the processing space S1 in the first gas diffusion chamber 101 will be large and the upper-stage mixing ratio will be low. However, according to the simulation results, when the aspect ratio of the constriction 121a was as small as 5, although the differential pressure was as large as approximately 45 Pa, the upper-stage mixing ratio was as high as 1.5%. On the other hand, when the aspect ratio of the constriction 121a was 10, the differential pressure was as large as approximately 75 Pa, and the upper-stage mixing ratio was as low as 0.04%.

[0071] Based on the above simulation results, in the present embodiment, the aspect ratio of the length L1 to the thickness R1 of the constriction 121a in the first gas supply path 121 is set to 10 or more, control is performed such that the differential pressure with the processing space S1 in the first gas diffusion chamber 101 is 47 Pa or more, and the gas amount per one of the plurality of first gas supply paths 121 is 0.15 sccm or more. Therefore, the mixing ratio in the upper stage, that is, the mixing ratio of the second processing gas (specifically, O2 gas) into the first gas diffusion chamber 101 can be decreased. That is, it is possible to further suppress the second processing gas jetted into the processing space S1 from flowing backward through the first gas supply path 121 including the constriction 121a and mixing into the first gas diffusion chamber 101. Accordingly, it is possible to suppress the occurrence of a risk caused by mixing of the first processing gas and the second processing gas.

[0072] <Modification Example> In the above example, O2 gas was used as the auxiliary combustion gas for forming the SiO film. However, instead, N2O gas may be used, or a mixed gas of O2 gas and N2O gas may be used. The first processing gas and the second processing gas may be used for forming a film other than the SiO film. For example, they may be used for forming a SiN film.

[0073] The embodiments disclosed this time should be considered as illustrative in all aspects and not restrictive. The above embodiments may be omitted, substituted, or changed in various forms without departing from the scope and gist of the appended claims.

Description of Reference Numerals

[0074] 1 Plasma processing apparatus 10 Container main body 14 Metal frame 20 Metal window 21 Partial window 30 Substrate support part 101 First gas diffusion chamber 102 Second gas diffusion chamber 111 First opening 112 Second opening 121 First gas supply path 121a Constriction 122 Second gas supply path G Glass substrate S1 Processing space U Control unit

Claims

1. A substrate processing apparatus for processing a substrate with a first gas and a second gas, comprising: a processing container having an internal processing space where the processing is performed on the substrate; a shower head for independently supplying the first gas and the second gas to the processing space; a control unit, wherein the shower head has, inside, a first gas diffusion chamber for diffusing the first gas and a second gas diffusion chamber, which is disposed below the first gas diffusion chamber, for diffusing the second gas; has, on its lower surface, a plurality of first openings for ejecting the first gas and a plurality of second openings for ejecting the second gas; has a plurality of first gas supply paths for communicating the first gas diffusion chamber with the plurality of first openings and a plurality of second gas supply paths for communicating the second gas diffusion chamber with the plurality of second openings; the control unit performs control such that a pressure difference between the first gas diffusion chamber and the processing space is 47 Pa or more and a gas flow rate per one of the plurality of first gas supply paths is 0.15 sccm or more; a constriction is provided in at least a part of each of the first gas supply paths; a substrate processing apparatus, wherein an aspect ratio of a length to a width of the constriction is 10 or more.

2. having a conduit passing through the second gas diffusion chamber, the substrate processing apparatus according to claim 1, wherein the conduit constitutes a part of each of the first gas supply paths.

3. The substrate processing apparatus according to claim 1 or 2, wherein one of the first gas and the second gas is a combustible gas and the other is a supporting combustion gas.

4. The substrate processing apparatus according to claim 3, wherein the first gas is a combustible gas and the second gas is a supporting combustion gas.

5. further comprising plasma generation means, wherein a film forming process is performed as the process by plasma generated from the first gas and the second gas using the plasma generation means. The substrate processing apparatus according to any one of claims 1 to 4.

6. A substrate processing method for processing a substrate with a first gas and a second gas using a substrate processing apparatus, wherein the substrate processing apparatus has a processing container having an internal processing space where the processing is performed on the substrate, and a shower head for independently supplying the first gas and the second gas to the processing space, wherein the shower head a first gas diffusion chamber for diffusing the first gas, and a second gas diffusion chamber disposed below the first gas diffusion chamber for diffusing the second gas, are provided inside; a plurality of first openings for ejecting the first gas and a plurality of second openings for ejecting the second gas are provided on the lower surface; a plurality of first gas supply paths for communicating the first gas diffusion chamber with the plurality of first openings, and a plurality of second gas supply paths for communicating the second gas diffusion chamber with the plurality of second openings are provided; a constriction is provided in at least a part of each of the first gas supply paths; the aspect ratio of the length to the width of the constriction is 10 or more; a substrate processing method, wherein a pressure difference between the first gas diffusion chamber and the processing space is 47 Pa or more, and control is performed such that the gas flow rate per one of the plurality of first gas supply paths is 0.15 sccm or more, and the substrate is subjected to the processing.

7. The substrate processing method according to claim 6, wherein one of the first gas and the second gas is a combustible gas and the other is a supporting combustion gas.

8. The substrate processing method according to claim 7, wherein the first gas is a combustible gas and the second gas is a supporting combustion gas.

9. The substrate processing apparatus further includes plasma generation means; The substrate processing method according to any one of claims 6 to 8, wherein a film forming process is performed as the processing by plasma generated from the first gas and the second gas using the plasma generation means.

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