SUBSTRATE PROCESSING APPARATUS AND SUBSTRATE PROCESSING METHOD

Abstract

To suppress the deposition of products while suppressing non-uniformity of substrate processing to a substrate.SOLUTION: A substrate processing device includes a processing vessel configured to be depressurizable, a placing table provided inside the processing vessel and having a substrate placing surface on which a substrate is placed, and a rectangular frame-shaped rectification wall provided to enclose the periphery of the substrate when the substrate is placed on the substrate placing surface. A gas channel that penetrates from the inside of the rectification wall is provided at each of the four corners of the rectification wall, and the inner surfaces of the four corners of the rectification wall are configured with curved surfaces.SELECTED DRAWING: Figure 2

Description

[Technical field]

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

[0002] Patent Document 1 discloses an etching processing apparatus in which a mounting table for mounting an FPD substrate is provided inside a vacuum chamber. In this etching processing apparatus, a straightening member having a height of about 50 to 150 mm is provided so as to surround the periphery of the substrate, and a gas pool is formed around the substrate by blocking the flow of etching gas near the outer peripheral region of the substrate with the straightening member. This reduces the flow rate of the etching gas in that region, and aims to increase the uniformity of the etching rate within the substrate surface. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2009-54720 A Summary of the Invention [Problem to be solved by the invention]

[0004] The technology according to the present disclosure suppresses deposition of by-products while suppressing non-uniformity in substrate processing on the substrate. [Means for solving the problem]

[0005] One aspect of the present disclosure is a substrate processing apparatus comprising: a processing vessel configured to be depressurized; a mounting table provided inside the processing vessel and having a substrate mounting surface on which a substrate is placed; and a rectangular frame-shaped straightening wall configured to surround an outer periphery of the substrate when the substrate is placed on the substrate mounting surface, wherein a gas flow path is provided for each of four corners of the straightening wall penetrating from the inside of the straightening wall, and inner surfaces of the four corners of the straightening wall are configured as curved surfaces. Effect of the Invention

[0006] According to the present disclosure, it is possible to suppress deposition of by-products while suppressing non-uniformity in substrate processing on a substrate. [Brief description of the drawings]

[0007] [Figure 1] 1 is a vertical cross-sectional view showing an outline of the configuration of a plasma processing apparatus as a substrate processing apparatus according to an embodiment of the present invention. [Diagram 2] 1 is a cross-sectional view showing an outline of the configuration of a plasma processing apparatus as a substrate processing apparatus according to an embodiment of the present invention. [Diagram 3] FIG. 4 is a partially enlarged plan view showing the outline of the configuration of a flow straightening wall and a wall member. [Figure 4] FIG. 4 is a partially enlarged cross-sectional view showing the outline of the configuration of a flow straightening wall and a wall member. [Diagram 5] FIG. 11 is a partially enlarged plan view showing the outline of the configuration of a flow straightening wall and a wall member according to a comparative embodiment. [Figure 6] FIG. 11 is a partially enlarged cross-sectional view showing the outline of the configuration of a flow straightening wall and a wall member according to a comparative embodiment. [Figure 7] 4 is a diagram for explaining a flow of a processing gas in the present embodiment. FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0008] In the manufacturing process of flat panel displays (FPDs) such as liquid crystal displays (LCDs), substrate processing such as etching and film formation is performed on substrates such as glass substrates. For these substrate processing operations, a substrate processing apparatus having a processing vessel in which the substrate to be processed is accommodated is used.

[0009] However, the substrate processing by the substrate processing apparatus may be different between the center and the periphery of the substrate, resulting in non-uniformity within the surface. For example, in an etching process using plasma, the etching rate is higher at the periphery of the substrate than at the center because reaction products generated during the process, which are a factor in inhibiting etching, are more easily discharged from the periphery of the substrate than from the center. For this reason, in Patent Document 1, a straightening member is provided to surround the periphery of the substrate, and the flow of the etching gas near the outer peripheral region of the substrate is blocked by the straightening member to form a gas pool around the substrate, reducing the flow rate of the etching gas in that region and making the etching rate uniform.

[0010] However, when the flow straightening member is provided as described above, deposition substances contained in reaction products generated during substrate processing may adhere to the flow straightening member and gradually accumulate thereon, which may cause particles.

[0011] Therefore, the technology according to the present disclosure suppresses deposition of by-products while suppressing non-uniformity in substrate processing on the substrate.

[0012] Hereinafter, a substrate processing apparatus and a substrate processing method according to the present embodiment will be described with reference to the drawings. In this specification and the drawings, elements having substantially the same functional configurations are denoted by the same reference numerals, and duplicated description will be omitted.

[0013] <Plasma processing device 1> 1 and 2 are a longitudinal sectional view and a transverse sectional view, respectively, showing the outline of the configuration of a plasma processing apparatus as a substrate processing apparatus according to this embodiment. 1 and 2 performs substrate processing, i.e., plasma processing, using plasma of a processing gas on a rectangular glass substrate G (hereinafter referred to as "substrate G") as a substrate. The plasma processing performed by the plasma processing apparatus 1 includes, for example, etching processing, film formation processing, ashing processing, etc. for FPD. By these processes, electronic devices such as light-emitting elements and driving circuits for the light-emitting elements are formed on the substrate G.

[0014] The plasma processing apparatus 1 includes a container body 10 having a bottom and a rectangular cylindrical shape. The container body 10 is made of a conductive material, for example, aluminum, and is electrically grounded. Since corrosive gas is often used in plasma processing, the inner wall surface of the container body 10 may be subjected to a corrosion-resistant coating treatment such as anodizing treatment in order to improve corrosion resistance. An opening is formed on the upper surface of the container body 10. This opening is airtightly closed by a rectangular metal window 20 provided insulated from the container body 10, specifically, 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 K1 in which a substrate G to be processed in plasma processing is located during plasma processing, and the space above the metal window 20 becomes an antenna chamber K2 in which a high-frequency antenna (plasma antenna) 100 described later is arranged. A load / unload port 11 for loading / unloading the substrate G into / from the processing space K1 and a gate valve 12 for opening / closing the load / unload port 11 are provided on a side wall of the container body 10 on the negative side in the X direction (the left side in FIG. 2).

[0015] 1, a mounting table 30 is provided on the bottom wall 10a of the container body 10 so as to face the metal window 20. The mounting table 30 has a base body 31, the upper surface of which serves as a substrate mounting surface 31a on which a substrate G is mounted, and the base body 31 is installed on the bottom wall 10a of the container body 10 via legs 32 formed of an insulating material. The mounting table 30 is formed, for example, in a rectangular shape as a whole in a plan view.

[0016] The table body 31 is made of a conductive material, such as aluminum. The surface of the table body 31 may be subjected to a coating process, such as anodizing or ceramic spraying, in order to improve insulation and corrosion resistance. The substrate G placed on the table body 31 is attracted and held by an electrostatic chuck (not shown) of the mounting table 30.

[0017] Furthermore, a high frequency power supply 41 is connected to the table body 31 via a matching box 40. The high frequency power supply 41 supplies high frequency power for bias, for example, high frequency power having a frequency of 3.2 MHz, to the table body 31. This allows ions in the plasma generated in the processing space K1 to be attracted to the substrate G.

[0018] A shield ring 50 is provided around the mounting table 30 so as to surround the substrate mounting surface 31a (specifically, so as to surround the upper side surface of the mounting table 30 including the substrate mounting surface 31a). The shield ring 50 is for uniformly forming plasma above the mounting table 30 and is made of an insulating material, for example, ceramics. The shield ring 50 is formed, for example, in a rectangular ring shape in a plan view. An insulating ring 51 is provided so as to surround the side surface of the mounting table 30 (specifically, the lower side surface of the mounting table 30) and the side surface of the leg 32, and the shield ring 50 is placed over the upper surface of the insulating ring 51 and the shoulder portion of the table body 31. The insulating ring 51 is supported by the bottom wall 10a of the container body 10. The leg portion 32 and the insulating ring 51 may be integrated together. The table body 31 may not be provided with a shoulder portion, in which case the shield ring 50 may be integrated with the insulating ring 51.

[0019] In one embodiment, the shield ring 50 constitutes a member support portion that supports a wall member 61 constituting a flow straightening wall 60 described below, and the upper surface of the shield ring 50 serves as a member mounting surface 50a that surrounds the outer periphery of the substrate mounting surface 31a of the mounting table 30 and on which the wall member 61 is mounted. For example, the member mounting surface 50a is formed flat, and its height is approximately equal to the height of the substrate mounting surface 31a.

[0020] In addition, a straightening wall 60 having a rectangular frame shape in a plan view, i.e., a rectangular frame shape, is provided so as to surround the outer periphery of the substrate G when the substrate G is placed on the substrate mounting surface 31a of the mounting table 30. The straightening wall 60 is for forming a gas pool on the peripheral portion of the substrate G by blocking the flow of gas on the peripheral portion of the substrate G placed on the mounting table 30, and is made of an insulating material such as ceramics. The flow straightening wall 60 is formed, for example, by placing a wall member 61 having a rectangular frame shape on the member mounting surface 50a of the shield ring 50. The wall member 61 will be described in detail later.

[0021] In the illustrated example, the substrate mounting surface 31a is larger than the substrate G and is contained within the substrate mounting surface 31a, but the substrate mounting surface 31a may be smaller than the substrate G and the peripheral portion of the substrate G may protrude from the substrate mounting surface 31a in a plan view and overlap with the inner peripheral portion of the component mounting surface 50a of the shield ring 50. In that case, it is desirable to make the component mounting surface 50a slightly lower than the substrate mounting surface 31a so that the back surface of the substrate G and the component mounting surface 50a of the shield ring 50 are spaced apart and do not come into contact with each other.

[0022] Further, an exhaust port 13 is formed in the bottom wall 10a of the container body 10. A plurality of exhaust ports 13 are provided, for example, one at each corner of the mounting table 30 having a rectangular shape in a plan view as shown in FIG. 2. An exhaust unit 70 having a vacuum pump or the like is connected to the exhaust port 13 as shown in FIG. 1. The processing space K1 is depressurized by the exhaust unit 70. The exhaust unit 70 may be provided for each of the plurality of exhaust ports 13, or may be provided in common to the plurality of exhaust ports 13. Also, a plurality of exhaust ports 13 (for example, two) may be provided along each side of the mounting table 30 having a rectangular shape in a plan view.

[0023] A metal frame 14, which is a rectangular frame made of a metal material such as aluminum, is provided on the upper surface side of the side wall of the container body 10. A seal member 15 for keeping the processing space K1 airtight is provided between the container body 10 and the metal frame 14. In this embodiment, the container body 10, the metal frame 14, and the metal window 20 form a processing container configured to be able to be depressurized.

[0024] The metal window 20 is formed, for example, in a rectangular shape when viewed from above. The metal window 20 also functions as a shower head that supplies a processing gas to the processing space K1. For example, the metal window 20 is formed with a number of gas discharge holes 21 that discharge the processing gas downward and a diffusion chamber 22 that diffuses the processing gas, and the gas discharge holes 21 and the diffusion chamber 22 are in communication with each other.

[0025] The diffusion chamber 22 is connected to a process gas supply unit 81 via a gas supply pipe 80. The process gas supply unit 81 includes a flow rate control valve (not shown), an on-off valve (not shown), and the like, and supplies process gases required for etching, film formation, ashing, and the like, to the diffusion chamber 22. The metal window 20 is electrically insulated from the metal frame 14 by an insulating member 23 .

[0026] The space surrounded by the metal window 20, the side wall portion 91, and the top plate portion 90 constitutes an antenna chamber K2, and a high-frequency antenna 100 is disposed inside the antenna chamber K2 so as to face the metal window 20.

[0027] The high frequency antenna 100 is disposed at a distance from the metal window 20 via a spacer (not shown) made of, for example, an insulating material.

[0028] A high frequency power supply 43 is connected to the high frequency antenna 100 via a matching box 42. High frequency power of, for example, 13.56 MHz is supplied to the high frequency antenna 100 from the high frequency power supply 43 via the matching box 42. As a result, an induction electric field is formed inside the processing space K1 during plasma processing, and the processing gas discharged from the gas discharge hole 21 is turned into plasma by the induction electric field.

[0029] Furthermore, the plasma processing apparatus 1 is provided with a control unit U. The control unit U is, for example, a computer equipped with a CPU, a memory, etc., and has a program storage unit (not shown). The program storage unit stores a program for controlling the processing of the substrate G in the plasma processing apparatus 1. The above-mentioned program may be recorded in a non-transitory computer-readable storage medium and installed from the storage medium into the control unit U. A part or all of the program may be realized by dedicated hardware (circuit board).

[0030] <Flow straightening wall 60 and wall member 61> Next, the configuration of the flow straightening wall 60 and the wall member 61 will be described with reference to Figures 1 and 2, and using Figures 3 and 4. Figures 3 and 4 are a partially enlarged plan view and a partially enlarged cross-sectional view, respectively, showing the outline of the configuration of the flow straightening wall 60 and the wall member 61, and showing one of the four corners of the flow straightening wall 60 and the wall member 61, which have a rectangular frame shape.

[0031] As described above, the flow straightening wall 60 is a frame body having a rectangular shape in a plan view. As shown in FIG. 2, the gas flow passage 200 is provided at each of the four corners of the flow straightening wall 60, penetrating the flow straightening wall 60 from the inside. Specifically, the gas flow passage 200 is provided at each of the four corners of the flow straightening wall 60, penetrating the flow straightening wall 60 from the inner peripheral surface thereof. As shown in FIG. 3, the gas flow passage 200 is formed so as to extend from the inner peripheral surface of the corner of the flow straightening wall 60 at which the gas flow passage 200 is provided, along the thickness direction of the corner in a plan view. More specifically, as shown in FIG. 3 and FIG. 4, the gas flow passage 200 is formed so as to extend from the inner peripheral surface of the corner of the flow straightening wall 60 at which the gas flow passage 200 is provided, along the thickness direction and horizontal direction of the corner, and reach the outer peripheral surface of the flow straightening wall 60.

[0032] In one embodiment, the gas flow passage 200 is formed by grooves 62 provided in the lower surface of each of the four corners of the wall member 61 and the component mounting surface 50a of the shield ring 50. For example, one groove 62 is formed in each of the four corners of the wall member 61 so as to extend along the thickness direction of the wall member 61 at the corner where the gas flow passage 200 is provided.

[0033] 3, the inner circumferential surfaces of the four corners of the flow straightening wall 60 are formed as curved surfaces 63. Specifically, the inner circumferential surfaces of the four corners of the wall member 61 constituting the flow straightening wall 60 are formed as curved surfaces 63 that are recessed outward.

[0034] The inner peripheral surface of the straightening wall 60, i.e., the inner peripheral surface of the wall member 61, is formed so as to be perpendicular to the component mounting surface 50a, for example. However, the inner peripheral surface of the straightening wall 60, i.e., the inner peripheral surface of the wall member 61, may be inclined outward or inward from perpendicular to the component mounting surface 50a, as long as the function of the straightening wall 60 can be fulfilled. In the following description, the inner peripheral surface of the straightening wall 60, i.e., the inner peripheral surface of the wall member 61, is assumed to be perpendicular to the component mounting surface 50a.

[0035] The wall member 61 may be divided into a plurality of parts. For example, the wall member 61 may be divided into corner members and side members. The gas flow passages 200 as described above are provided only at the four corners of the flow straightening wall 60, and are not provided on the sides of the flow straightening wall 60.

[0036] <Substrate processing> Next, a substrate processing in the plasma processing apparatus 1 will be described taking an example of an etching process using plasma, that is, a plasma etching process. The substrate processing described below is performed under the control of a control unit U.

[0037] First, the substrate G is placed on the placement table 30 . Specifically, the gate valve 12 is opened, and the substrate G is loaded into the processing space K1 through the load / unload port 11, and placed on the substrate mounting surface 31a of the mounting table 30 so as to be surrounded by the flow straightening wall 60. Thereafter, the gate valve 12 is closed.

[0038] The processing gas introduced into the processing space K1 is supplied to the substrate G on the substrate mounting surface 31a, and processing is performed on the substrate G. Specifically, the processing gas is turned into plasma, and the substrate G is processed by the plasma.

[0039] More specifically, the processing gas is supplied from the processing gas supply unit 81 into the processing space K1 through the diffusion chamber 22 and the gas outlet holes 21. In addition, the processing space K1 is evacuated by the exhaust unit 70, and the inside of the processing space K1 is adjusted to a desired pressure. Next, high frequency power is supplied from the high frequency power source 43 to the high frequency antenna 100, which generates a uniform induction electric field in the processing space K1 through the metal window 20. As a result, the processing gas in the processing space K1 is converted into plasma by the induction electric field, and high density inductively coupled plasma is generated. Then, ions in the plasma are attracted to the substrate G by the bias high frequency power supplied from the high frequency power source 41 to the table body 31 of the mounting table 30, and the substrate G is subjected to an etching process.

[0040] As described above, the plasma processing apparatus 1 is provided with the flow straightening wall 60 having the gas flow passage 200 formed at each of the four corners. During the above-mentioned etching process, the processing gas introduced into the processing space K1 and supplied to the substrate G is guided to the exhaust port 13 through the upper side of the flow straightening wall 60 and the gas flow passage 200, and then discharged. The reaction products generated during the etching process, together with the processing gas that did not contribute to the processing of the substrate G, are guided to the exhaust port 13 through the upper side of the flow straightening wall 60 and the gas flow passage 200, and then discharged.

[0041] After the etching process is completed, the power supply from the high frequency power sources 41 and 43 and the supply of the processing gas from the processing gas supply unit 81 are stopped, and the substrate G is unloaded in the reverse order to that in which it was loaded. This completes the series of substrate processing steps.

[0042] <Main Effects of This Embodiment> However, unlike the present embodiment, when the straightening wall 60 is not provided, the etching rate may be higher in the peripheral portion of the substrate G than in the central portion. This is because the reaction products generated during processing, which are a factor in suppressing etching, are more easily discharged from the peripheral portion of the substrate G than from the central portion. Since the reaction products are generated only from the surface of the substrate G, whereas the processing gas is supplied from the processing space K1, the peripheral portion of the substrate G is easily replaced with fresh processing gas if exhaust proceeds quickly. Therefore, the straightening wall 60 is provided to surround the substrate G on the mounting table 30, and the processing gas supplied to the substrate G is discharged along the inner peripheral surface and upper surface of the straightening wall 60, so that the flow of the processing gas near the peripheral portion of the substrate G is blocked by the straightening wall 60, and a gas pool is formed around the substrate G. As a result, the ratio of unreacted reactive species (radicals, ions, etc. that contribute to the reaction) in the plasma becomes close between the central portion and the peripheral portion of the substrate G, so that the etching rate can be uniform in the surface.

[0043] However, even if the straightening wall 60 is provided, if the gas flow passages 200 are not formed at the four corners of the straightening wall 60 as in the present embodiment, sedimentary substances contained in the reaction products will adhere to and gradually accumulate on the straightening wall 60. In particular, due to the rectangular frame-like structure of the straightening wall 60, sedimentary substances contained in the reaction products will accumulate on the corners of the straightening wall 60, and the accumulated products may become a cause of particles. Therefore, in this embodiment, gas flow passages 200 are provided at the four corners of the flow straightening wall 60, and the reaction products near the corners are discharged through the gas flow passages 200 together with the processing gas. In the following, for the sake of simplicity, the expression "the reaction product is deposited" may be used, but this does not mean that all of the substances contained in the reaction product are deposited, and as mentioned above, it means that the depository substances contained in the reaction product are deposited.

[0044] 5 and 6 are possible comparative embodiments different from the present embodiment. In the comparative embodiment shown in Fig. 5 and 6, support columns 511 are provided between a wall member 510 constituting a rectangular frame-shaped flow straightening wall 500 capable of surrounding the outer periphery of a substrate G and the member mounting surface 50a, and the wall member 510 is supported by the support columns 511 with gaps 512 provided between the wall member 510 and the member mounting surface 50a. In the comparative embodiment, a plurality of support columns 511 are provided for each side of the rectangular frame-shaped flow straightening wall 500, and gaps 512 are provided at a plurality of locations including each corner of the flow straightening wall 500. In this embodiment, reaction products generated during the processing of the substrate G can be exhausted through the gap 512 together with the processing gas.

[0045] However, in this comparative embodiment, as shown in FIG. 6, the reaction product Q may accumulate on the substrate G side of the support column 511. In particular, the reaction product Q may accumulate on the substrate G side of the support column 511 provided near the center of the side of the straightening wall 500. The reason for this is considered to be as follows. In the comparative embodiment, the discharge path of the process gas is a path through the gap 512, that is, a path through the space between the adjacent support columns 511, except for the path through the upper side of the straightening wall 500. In other words, the support column 511 is present in the flow of the process gas passing through the gap 512. Therefore, the flow of the process gas from the substrate G side toward the support column 511 (see the arrow F10 in FIG. 5) is strong. For this reason, it is considered that the number of reaction products that reach the support column 511 is large, and the reaction products that reach the support column 511 are pressed against the support column 511 by the flow of the process gas, and the depositing substances contained in the reaction products are deposited.

[0046] 7, in this embodiment, the gas flow paths 200 are provided only at the four corners of the straightening wall 60, so that a flow F1 of the process gas is formed along the side of the straightening wall 60 toward the four corners, and the flow F2 of the process gas from the substrate G toward the side of the straightening wall 60 is weakened. This makes it possible to reduce the number of reaction products (per unit area) that reach the side of the straightening wall 60, and also makes it difficult for the reaction products that have reached the side of the straightening wall 60 to be pressed against the side. Therefore, it is possible to suppress the accumulation of the reaction products on the side of the straightening wall 60.

[0047] In addition, in this embodiment, the inner peripheral surfaces of the four corners of the flow straightening wall 60 are formed as curved surfaces 63. Therefore, the process gas that reaches the four corners tends to flow along the curved surfaces 63 without stagnation at the four corners. Therefore, it is possible to prevent the process gas from stagnation at the four corners, and it is possible to prevent the reaction products from accumulating in the parts of the four corners where the gas flow passages 200 are not formed.

[0048] As described above, according to this embodiment, it is possible to suppress the deposition (particularly in corners) of reaction products generated during the plasma etching process while suppressing non-uniformity of the plasma etching process on the substrate. The above points also apply to plasma processes other than the plasma etching process and substrate processes using process gases other than the plasma process. In other words, according to this embodiment, it is possible to suppress the deposition (particularly in corners) of reaction products generated during the substrate processing while suppressing non-uniformity of the substrate processing.

[0049] Furthermore, according to this embodiment, since reaction products are less likely to accumulate on the flow straightening wall 60, the cycle of maintenance of the flow straightening wall 60 for removing deposits can be extended, and a decrease in productivity can be suppressed.

[0050] Furthermore, in this embodiment, since the gas flow passages 200 are provided only at the four corners of the flow straightening wall 60, the flow rate of the processing gas passing through the gas flow passage 200 is high. Therefore, reaction products including substances causing deposits are discharged without remaining in the gas flow passage 200. In other words, the deposition of the reaction products in the gas flow passage 200 can be suppressed.

[0051] <Dimensions and locations of the flow straightening wall 60 and the wall member 61> 3 and 4, an example of the dimensions and arrangement positions of the flow straightening wall 60 and the wall member 61 will be described. These are determined depending on the type of reaction product and the type of processing gas (which is reflected in the conductance of the gas flow passage 200 required to exhaust the reaction product), the size of the substrate G, the processing pressure, etc.

[0052] When the distance L1 between the side end (specifically, its design value) of the substrate G placed on the substrate mounting surface 31a and the inner peripheral surface of the edge of the straightening wall 60 and the wall member 61 is 8 mm, and the thickness of the substrate G is 0.5 mm to 0.7 mm, the dimensions and arrangement positions of the straightening wall 60 and the wall member 61 are, for example, as follows.

[0053] Height H1 of the flow straightening wall 60 and the wall member 61: 20 mm to 80 mm Thickness of flow wall 60: 5mm~36mm Height H2 of gas flow path 200: 1mm to 10mm Distance L2 from the corner of the substrate G to the side end of the gas flow path 200: 0 mm to 20 mm Angle θ of the side surface of the gas flow passage 200 (based on the angle perpendicular to the edge of the flow straightening wall 60 on which the side surface is formed): 0° to 45°

[0054] In addition, the angle θ of 45° means that the gas flow path 200 extends along the thickness direction of the corner of the flow straightening wall 60 in which the gas flow path 200 is provided, and is formed to have a uniform width along the thickness direction. Furthermore, when the angle θ is greater than or equal to 0° and less than 45°, this means that the gas flow path 200 extends along the thickness direction of the corner of the straightening wall 60 in which the gas flow path 200 is provided, and is formed in a shape that opens outward.

[0055] When the angle θ is less than 0°, i.e., when it is a negative value, the gas flow passage 200 is formed in a shape that opens further outward than when the angle is 0°, and there is a risk that the process gas will bend around the inlet of the gas flow passage 200, causing deposition of reaction products. This can be prevented by setting the angle θ to 0° or more. Furthermore, when the angle θ is less than 0°, there is a high possibility that gas will diffuse back from the exhaust side to the substrate G side through the gas flow passage 200. This back diffusion can be suppressed by setting the angle θ to 0° or more.

[0056] On the other hand, if the angle θ exceeds 45°, the ratio of the process gas and the reaction products contained therein that collide with the inner surface of the gas flow passage 200 may increase, that is, the performance of discharging the reaction products may decrease. By setting the angle θ to 45° or less, it is possible to prevent the performance of discharging the reaction products from decreasing.

[0057] Furthermore, when the distance L2 from the corner of the substrate G to the side end of the gas flow path 200 is a negative value, that is, when the position of the corner of the substrate G is closer to the side of the wall member 61 than the side end of the gas flow path 200, the performance of discharging the reaction products may also be degraded. Therefore, by setting the distance L2 to 0 mm or more, it is possible to prevent the performance of discharging the reaction products from degrading. On the other hand, if the distance L2 exceeds 20 mm, the exhaust efficiency of the process gas may differ between the corners and other parts of the substrate G, which may affect the uniformity of the substrate processing. By setting the distance L2 to 20 mm or less, it is possible to suppress such an effect on the uniformity of the substrate processing.

[0058] Furthermore, it is preferable that the straightening wall 60 and the wall member 61 are formed so that the radius of curvature r of the curved surface 63 is equal to, for example, the distance L2 between the side end of the substrate G placed on the substrate mounting surface 31a and the inner surfaces of the edges of the straightening wall 60 and the wall member 61. By forming the curved surface 63 as described above, it is possible to keep constant the distance between the side edge of the substrate G and the inner peripheral surfaces of the sides of the flow straightening wall 60 and the wall member 61 at any location. Therefore, it is possible to improve the uniformity of the substrate processing at the corners of the substrate G. It is preferable that the radius of curvature r of the curved surface 63 be set in accordance with the dimensions of the substrate G to be placed on the substrate placement surface 31a, but the substrate G is not an essential component of this embodiment.

[0059] (Modification) In the above example, the gas flow path 200 is formed by the groove 62 provided in the bottom surface of the wall member 61 and the component mounting surface 50a. The form of the gas flow path 200 is not limited to this, and for example, the gas flow path 200 may be a hole penetrating the wall member 61. The gas flow path 200 may also be formed by the flat bottom surface of the wall member 61 and a groove provided in the component mounting surface 50a of the shield ring 50, and further, the gas flow path 200 may be a hole penetrating the shield ring 50 from a position on the component mounting surface 50a of the shield ring 50 that is more inward than the wall member 61.

[0060] However, when the gas flow passage 200 is formed by the grooves provided in the member mounting surface 50a and the flat bottom surface of the wall member 61, a step occurs between the member mounting surface 50a on the inner side of the wall member 61 and the gas flow passage 200. In contrast, when the gas flow passage 200 is formed by the grooves 62 provided in the bottom surface of the wall member 61 and the member mounting surface 50a, there is no step between the member mounting surface 50a on the inner side of the wall member 61 and the gas flow passage 200. Therefore, due to the step-free configuration, the process gas that has traveled toward the gas flow passage 200 along the member mounting surface 50a on the inner side of the wall member 61 can be smoothly discharged to the outside of the wall member 61 through the gas flow passage 200. Therefore, the discharge performance of the reaction product is high, and the deposition of the reaction product can be suppressed.

[0061] In the above examples, the gas flow passage 200 is formed to extend in the horizontal direction, but as long as the desired discharge performance of the reaction products is obtained, the gas flow passage 200 may be formed to be inclined from the horizontal direction so that the downstream end (the outside of the straightening wall) is located above or below the upstream end (the inside of the straightening wall).

[0062] The embodiments disclosed herein should be considered as illustrative and not restrictive in all respects. The above-described embodiments may be omitted, substituted, or modified in various forms without departing from the scope and spirit of the appended claims. [Explanation of symbols]

[0063] 1. Plasma processing equipment 10 Container body 14 Metal Frame 20 Metal Window 30 Placement table 31a Substrate mounting surface 60 Rectification wall 63 Curved surface 200 Gas flow path G Glass substrate

Claims

1. A processing vessel configured to be decompressible; a mounting table provided inside the processing chamber and having a substrate mounting surface on which a substrate is placed; a rectangular frame-shaped flow straightening wall provided so as to surround an outer periphery of the substrate when the substrate is placed on the substrate placement surface, a gas flow passage penetrating the flow straightening wall from an inner side is provided at each of four corners of the flow straightening wall, In the substrate processing apparatus, inner circumferential surfaces at four corners of the flow straightening wall are formed as curved surfaces.

2. The substrate is rectangular; 2 . The substrate processing apparatus according to claim 1 , wherein a radius of curvature of the curved surface is equal to a distance between a side edge of the substrate and an inner circumferential surface of a side portion of the flow straightening wall when the substrate is placed on the substrate placement surface.

3. a member support portion having a member mounting surface surrounding an outer periphery of the substrate mounting surface; a wall member that is placed on the member placement surface and forms the flow straightening wall, The substrate processing apparatus according to claim 1 , wherein the gas flow path is defined by a groove provided in a lower surface of the wall member and the member mounting surface.

4. The substrate mounting surface further includes a ring member provided to surround the substrate mounting surface, The substrate processing apparatus according to claim 3 , wherein the ring member and its upper surface constitute the member support portion and the member placement surface, respectively.

5. 5. The substrate processing apparatus according to claim 1, wherein the gas flow path extends along a thickness direction of a corner of the flow straightening wall in which the gas flow path is provided, and is formed to have a uniform width along the thickness direction.

6. 5. The substrate processing apparatus according to claim 1, wherein the gas flow passage extends along a thickness direction of a corner of the flow straightening wall in which the gas flow passage is provided, and is formed in a shape that opens outward.

7. a step of placing a substrate on a substrate placement surface of a placement table provided inside a processing chamber so as to be surrounded by a rectangular frame-shaped flow straightening wall having inner circumferential surfaces at four corners formed by curved surfaces; supplying the processing gas introduced into the processing chamber to the substrate on the substrate mounting surface to process the substrate; and discharging the processing gas supplied to the substrate on the substrate mounting surface through gas flow passages extending from an inner circumferential surface of the flow straightening wall provided at each of the four corners of the flow straightening wall and through an upper side of the flow straightening wall.

8. 8. The substrate processing method according to claim 7, wherein the processing step comprises converting the processing gas into plasma and processing the substrate with the plasma.

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