Substrate processing apparatus and substrate processing method

Abstract

The present application relates to a substrate processing apparatus and a substrate processing method. A processing state of a peripheral edge portion of a substrate is adjusted locally and easily. A substrate processing apparatus is configured to include: a processing container that accommodates a substrate; a stage that is provided inside the processing container, has a placement region that places the substrate, and is provided with a lower wall that is formed along a peripheral edge of the placement region and is provided to the stage in a manner of surrounding the substrate; and an upper wall that is formed independently of the lower wall and locally projects upward in a wall periphery of the lower wall.

Description

Technical Field

[0001] This disclosure relates to a substrate processing apparatus and a substrate processing method. Background Technology

[0002] Gas treatments such as etching are performed on a rectangular substrate when viewed from above. In the apparatus for performing this gas treatment, a rectangular frame-like member (rectifier wall) is sometimes provided to surround the substrate, and the gas flow from the center side of the substrate to the outer periphery is blocked by the member, thereby adjusting the processing speed at the periphery of the substrate.

[0003] Patent Document 1 shows a component with a uniform height at its upper end. Furthermore, Patent Document 2 shows a component where the height of the four corners is lower than the height of other parts to suppress the retention of etching gas at the four corners of the substrate. Moreover, Patent Document 3 shows a component composed of multiple parts of varying heights arranged laterally. By appropriately replacing each part, the degree of etching gas retention at different parts of the substrate can be adjusted.

[0004] Existing technical documents

[0005] Patent documents

[0006] Patent Document 1: Japanese Patent Application Publication No. 2009-54720

[0007] Patent Document 2: Japanese Patent Application Publication No. 2003-243364

[0008] Patent Document 3: Japanese Patent Application Publication No. 2013-243184 Summary of the Invention

[0009] The problem the invention aims to solve

[0010] The purpose of this disclosure is to provide a technique that enables localized and easy adjustment of the processing state of the peripheral end of a substrate.

[0011] Solution for solving the problem

[0012] The substrate processing apparatus disclosed herein includes:

[0013] A processing container that holds a substrate;

[0014] A stage, disposed within the processing container, having a mounting area for mounting the substrate;

[0015] A gas supply unit supplies processing gas to process a substrate placed in the mounting area.

[0016] An exhaust port that vents air from the processing container;

[0017] A lower wall, which is formed along the periphery of the placement area and disposed on the stage in a manner that surrounds the substrate; and

[0018] The upper wall protrudes upward locally around the periphery of the lower wall and is formed independently of the lower wall.

[0019] The effects of the invention

[0020] This disclosure allows for localized and easy adjustment of the processing state of the peripheral end of the substrate. Attached Figure Description

[0021] Figure 1 This is a longitudinal sectional side view of an etching apparatus of a substrate processing apparatus according to one embodiment of the present disclosure.

[0022] Figure 2 This is a schematic perspective view of the stage and rectifier wall provided in the etching apparatus.

[0023] Figure 3 This is a top cross-sectional view of the rectifying wall.

[0024] Figure 4 This is a side view of the rectifying wall.

[0025] Figure 5 This is a three-dimensional view of the upper and lower walls that constitute the rectifying wall.

[0026] Figure 6 This is a perspective view of the upper wall and the lower wall.

[0027] Figure 7 This is a longitudinal sectional side view of the rectifying wall.

[0028] Figure 8 This is a side view of the rectifying wall.

[0029] Figure 9 This is a side view of the rectifying wall.

[0030] Figure 10 This is an explanatory diagram representing the results of an evaluation experiment.

[0031] Figure 11 This is an explanatory diagram representing the results of an evaluation experiment. Detailed Implementation

[0032] Refer to the longitudinal sectional side view Figure 1The etching apparatus 1, which is one embodiment of the substrate processing apparatus disclosed herein, will be described. This etching apparatus 1 supplies an etching gas as a processing gas to a substrate G and plasma-entrains the etching gas, thereby etching an aluminum (Al) film or the like formed on the surface of the substrate G. The substrate G is, for example, a glass substrate for manufacturing FPDs (Flat Panel Displays), and more specifically, a substrate for manufacturing liquid crystal displays (LCDs), electroluminescent displays (ELs), plasma display panels (PDPs), etc. Furthermore, the substrate G is rectangular when viewed from above.

[0033] The etching apparatus 1 includes a metal processing container 11 that houses and processes a substrate G inside the container, and the processing container 11 is grounded. A feed port 13 for the substrate G is formed on the side wall of the processing container 11 and is opened and closed by a gate valve 12.

[0034] A stage 21 is provided at the bottom of the processing container 11, and a substrate G is placed on the upper surface of the stage 21. The stage 21 is prism-shaped and has a lower electrode 22 made of a conductive material such as metal and an annular member 23 made of an insulating material, the annular member 23 covering the periphery of the lower electrode 22. The upper surface of the lower electrode 22 forms a mounting surface 29 for mounting the substrate G. The mounting surface 29 can be made larger than the substrate G, or it can be made slightly smaller than the substrate G, so that the periphery of the substrate G protrudes slightly beyond the periphery of the mounting surface 29. In either case, the mounting surface 29 is rectangular in shape corresponding to the substrate G. The lower electrode 22 is connected to a high-frequency power supply 25 via a matching device 24. Furthermore, an insulating member 26 is provided between the stage 21 and the bottom wall of the processing container 11 to insulate them from each other.

[0035] The platform 21 is provided with a plurality of lifting pins 27 extending in the vertical direction. The lower end of each lifting pin 27 is connected to a lifting mechanism 28 disposed outside the processing container 11 via an opening at the bottom of the processing container 11. The lifting mechanism 28 can be configured as follows: Figure 1As shown, multiple lifting pins 27 are commonly arranged; alternatively, they can be arranged individually. Using the lifting mechanism 28, the lifting pins 27 are raised and lowered vertically, transferring the substrate G between the upper surface of the stage 21 and the substrate transport mechanism (not shown) that enters the processing container 11 via the transport port 13. Furthermore, the stage 21 is provided with an electrostatic chuck for electrostatically adsorbing the placed substrate G, a fluid flow path for adjusting the temperature of the upper surface of the stage 21, and a heat transfer gas outlet for heat exchange between the upper surface of the stage 21 and the substrate G; however, these are not shown in the diagram.

[0036] At the bottom of the processing container 11, a plurality of exhaust ports 14 are provided on the outer side of the stage 21. By providing such placement at the bottom of the processing container 11, each exhaust port 14 opens to a position lower than the upper surface of the stage 21 on which the substrate G is placed. An exhaust pipe 15 is connected to one end of each exhaust port 14, and the other end of the exhaust pipe 15 is connected to an exhaust mechanism 17, which is composed of a vacuum pump or the like. By using the exhaust mechanism 17 to exhaust air from the exhaust ports 14, a vacuum atmosphere at the desired pressure is created inside the processing container 11.

[0037] The top of the processing container 11 is configured as a nozzle 31 opposite the stage 21, and the nozzle 31 is connected to a supply source 32 for etching gas, which is the processing gas. Etching gas is supplied from the gas supply source 32 to the nozzle 31, and the etching gas is ejected onto the stage 21 from a plurality of gas outlets 33 provided on the lower surface of the nozzle 31. Furthermore, the nozzle 31, which serves as the gas supply section, is configured as a grounded upper electrode. The nozzle 31 and the lower electrode 22 of the stage 21 constitute a parallel plate electrode for forming plasma.

[0038] Furthermore, as described in the background section, when processing a substrate (hereinafter referred to as a rectangular substrate) that is rectangular in plan view, such as substrate G, using a substrate processing apparatus, a member (rectifying wall) surrounding the rectangular substrate is sometimes provided to restrict and rectify the flow of gas around the rectangular substrate. On the other hand, from the viewpoint of maximizing the efficiency of manufacturing a display with an effective area from the rectangular substrate, it is desirable for the area where uniform processing is performed in the plane of the rectangular substrate to further expand towards the periphery of the rectangular substrate. In other words, by aligning the processing state (etching amount in the case of etching) of the region near the periphery of the rectangular substrate with the processing state of the central side of the rectangular substrate, the uniformity of the overall in-plane processing of the substrate is improved.

[0039] However, if the height of the upper end is made uniform around the perimeter of the rectifying wall (the frame-shaped portion constituting the rectifying wall, the same applies below. The same applies to the lower wall described later), the rectifying wall will not be effective enough, and the processing speed in local areas near the perimeter of the rectangular substrate (perimeter end) will be higher, which will be described in detail later. As a result, over-processing is performed compared to other areas. Consequently, the uniformity of processing may not be sufficiently improved within the surface of the substrate. The etching apparatus 1 of this embodiment includes the rectifying wall 4 described later, thus becoming a structure capable of suppressing the over-processing in the aforementioned local areas and eliminating the aforementioned problem of processing uniformity. In addition, here, "high uniformity" means good uniformity, which refers to a "small" state when uniformity is numerically quantified as a percentage of deviation, etc. The terms "large" and "small" will also be used below when evaluating uniformity using numerical values.

[0040] Furthermore, the localized areas of processing overload at the periphery of the substrate, which occur when the height of the upper part of the aforementioned rectifying wall is uniform, vary depending on various processing conditions such as the pressure inside the processing container, the supply of etching gas, and the location of the exhaust port inside the processing container (described later). Since a detailed description will follow, its structure will be briefly described here. The rectifying wall 4 is constructed by stacking upper walls 42 on top of each other on a lower wall 41 surrounding the substrate G or surrounding the mounting area of ​​the substrate G. Moreover, the lower wall 41 and the upper wall 42 are independent components. Therefore, the upper wall 42 can be positioned at a desired location in the circumferential direction of the lower wall 41. Thus, as long as the upper wall 42 is positioned corresponding to the location of the aforementioned localized areas of processing overload at the periphery of the substrate G, it is easy to improve the uniformity of the processing.

[0041] The following also refers to Figure 2 3D image Figure 3 The top view illustrates the stage 21 and its surrounding structure. The upper surface of the stage 21 is horizontal, and at least partially therein forms a mounting area for mounting the substrate G. The mounting area is a region that has the same shape and area as the substrate G when the substrate G is mounted, and corresponds one-to-one with the substrate G. When the mounting surface 29 is larger than the substrate G, the mounting area is contained within the mounting surface 29; when the mounting surface 29 is smaller than the substrate G, the mounting area includes the mounting surface 29 and involves a portion of the area inside the upper surface of the annular member 23. Furthermore, the substrate G is mounted such that its center coincides with the center of the upper surface of the stage 21. Corresponding to the shape of the substrate G, the upper surface of the stage 21 is rectangular, and the aforementioned flow-rectifying wall 4 is provided such that it surrounds the substrate G on the stage 21 along the periphery of the upper surface.

[0042] The lower wall 41 constituting the rectifying wall 4 is rectangular. Furthermore, this lower wall 41 is slightly away from the periphery of the substrate G or the mounting area placed on the stage 21, and is disposed along the periphery of the substrate G (i.e., along the periphery of the mounting area of ​​the substrate G). Therefore, the lower wall 41 has a rectangular shape when viewed from above. In the lower wall 41, the portions forming the two long sides of the rectangle are designated as long wall portions 41A, and the portions forming the two short sides are designated as short wall portions 41B. The long wall portions 41A and short wall portions 41B are each configured as vertical plates, with the two long wall portions 41A, which are the first wall portions, facing each other, and the two short wall portions 41B, which are the second wall portions, facing each other. Furthermore, the first wall portions and the second wall portions are adjacent to each other. In the following description, the horizontal direction is sometimes referred to as the X direction and the Y direction. The X direction and the Y direction are straight lines and are orthogonal to each other. When viewed from above, the long side of the long wall portion 41A and the substrate G is along the X direction, and the short side of the short wall portion 41B and the substrate G is along the Y direction.

[0043] For the lower wall 41, the heights of all portions along its perimeter are the same. That is, for the long wall portion 41A, the heights of all portions along the X direction are the same (flat at the top), and for the short wall portion 41B, the heights of all portions along the Y direction are the same (flat at the top). Furthermore, the two opposing long wall portions 41A and the two opposing short wall portions 41B are the same height, and adjacent long wall portions 41A and short wall portions 41B are also the same height. Therefore, the height of the upper end of the lower wall 41 along its perimeter is consistent. In addition, the consistent height mentioned here means that the height is consistent in design, and even if some deviations occur due to slight tilting of the stage 21, manufacturing errors of the lower wall 41, etc., these are included in the case of consistent height. In addition, the upper end of the lower wall 41 is located above the surface of the substrate G.

[0044] Since exhaust gas is discharged from the exhaust port 14 located on the outside of the stage 21, the plasma-enhanced etching gas supplied from the nozzle 31 to the substrate G flows from the center of the substrate G to the outer periphery. The lower wall 41 blocks the etching gas flowing outward in this way, forming a gas accumulation at the peripheral end of the substrate G and reducing its flow rate. As a result, the supply of unreacted plasma active species in the etching gas to the peripheral end of the substrate G is suppressed, and consequently, the amount of etching at that peripheral end is suppressed.

[0045] If the lower wall 41 is not provided, as described in Patent Document 1, the supply of plasma-active species to the peripheral end is excessive, and the etching rate (etching amount per unit time) of the substrate G tends to be larger at the peripheral end than at the central part. In other words, the lower wall 41 suppresses the etching rate at the peripheral end of the substrate G, improving the uniformity of the etching amount between the central and peripheral ends of the substrate G. Furthermore, in this example, the height of the lower wall 41 is 45 mm.

[0046] Furthermore, the upper wall 42 constituting the rectifying wall 4 is provided to prevent the formation of areas with high etching amounts locally at the peripheral end of the substrate G. To explain the function of the upper wall 42 in detail, a brief description of the evaluation test, which will be described in detail later, is provided. When the etching apparatus 1 was used to process the substrate G with only the lower wall 41 and no upper wall 42 provided, areas with high etching amounts (i.e., areas with high processing speeds) were formed locally at the peripheral end of the substrate G. Specifically, the etching amount was higher in the area near each exhaust port 14. This is believed to be because the etching gas is concentrated in the area near the exhaust port 14 due to the exhaust, and therefore, the supply of unreacted active species is greater than in other areas, resulting in a higher etching rate.

[0047] The upper wall 42 is configured to partially protrude upwards from the upper end of the lower wall 41 around its periphery. Therefore, by providing the upper wall 42, the upper end of the rectifying wall 4 is locally increased around its periphery. The upper wall 42 is located near each exhaust port 14 on the lower wall 41. Consequently, at the periphery of the rectifying wall 4, the effect of restricting and retaining the flow of the etching gas is increased, reducing the supply of active materials to areas with higher etching amounts that would be present without the upper wall 42.

[0048] Furthermore, near the exhaust port 14, especially in cases where a turbomolecular pump or similar device is used in the vacuum pump of the exhaust mechanism 17, it is believed that particles temporarily discharged through the exhaust port 14 along with etching gases may be backflowed by the vacuum pump and reach the substrate G side from the exhaust port 14 side. The upper wall 42 restricts the backflow of particles towards the substrate G side, suppressing particles from reaching the substrate G side. Therefore, the upper wall 42 also has the function of suppressing particle contamination in the area near the exhaust port 14. By utilizing the function of the upper wall 42 in this way, while suppressing contamination of the substrate G caused by backflowing particles, it also suppresses the high etching amount in local areas at the peripheral end of the substrate G, improving the uniformity of the etching amount in all parts of the substrate G. In the evaluation test, it was confirmed that the uniformity of the etching amount was improved by providing the upper wall 42.

[0049] The structure and configuration of the upper wall 42 and the exhaust port 14 in this embodiment will be described in detail below. Furthermore, this structure and configuration are the same as those used in the evaluation test. In this embodiment, two exhaust ports 14 are provided along each long side of the placement area on the platform 21, and two are provided along each short side of the placement area, for a total of eight. The eight exhaust ports 14 are separated from each other and, when viewed from above, open upwards from the bottom of the processing container 11 in a manner that surrounds the platform 21. Moreover, as... Figure 3As shown, the eight exhaust ports 14 are configured such that, when viewed from above, they are symmetrical with respect to an imaginary line L1 along the Y direction, which extends along the center of the long side of the loading area on the platform 21 in the X direction, and symmetrical with respect to an imaginary line L2 along the X direction, which extends along the center of the short side of the loading area on the platform 21 in the Y direction. Furthermore, each exhaust port 14 is not located at a corner of the platform 21 when viewed from above, but rather opens slightly closer to the center of the long side of the platform 21 extending in the X direction and slightly closer to the center of the short side extending in the Y direction than at the corner.

[0050] The upper wall 42 has eight outlets, the same number as the exhaust ports 14, positioned separately from each other along the circumference of the lower wall 41. Two upper walls 42 are arranged on each long wall portion 41A, and two are arranged on each short wall portion 41B. Each upper wall 42 is plate-shaped, rectangular when viewed relative to its main surface, and its bottom surface is connected to the upper end surface of the lower wall 41. Therefore, the upper ends of the upper walls 42 on the long wall portions 41A are at the same height when viewed along the X direction, and the upper ends of the upper walls 42 on the short wall portions 41B are at the same height when viewed along the Y direction. Furthermore, the heights of the upper walls 42 on adjacent long wall portions 41A and short wall portions 41B are also the same. In other words, when viewed along the circumference of the lower wall 41, the upper ends of each part of an upper wall 42 are at the same height. Moreover, the upper ends of different upper walls 42 are also at the same height. In this example, the height of the upper wall 42 is 30mm. In addition, due to this structure, the width (length in the X direction) of the upper wall 42 provided on the long wall portion 41A is shorter than the width (length in the X direction) of the long wall portion 41A, and the width (length in the Y direction) of the upper wall 42 provided on the short wall portion 41B is shorter than the width (length in the Y direction) of the short wall portion 41B.

[0051] The configuration of the upper wall 42 will be described in further detail. The upper wall 42 on the long wall portion 41A is located at a position offset in the Y direction relative to the exhaust port 14 which is provided along the long side (along the X direction) of the mounting area. Furthermore, the upper wall 42 on the short wall portion 41B is located at a position offset in the X direction relative to the exhaust port 14 which is provided along the short side (along the Y direction) of the mounting area when viewed from above. This configuration is achieved because, in evaluation tests, by arranging the upper wall 42 in a manner that would separate the areas (hereinafter referred to as areas G1, G2) where the etching amount at the peripheral end of the substrate G would be locally larger when the upper wall 42 is not provided from the exhaust port 14 when viewed from above, the aforementioned effect of the upper wall 42 is achieved.

[0052] That is, when the substrate G is placed in the mounting area, at the end of the substrate G along the long side, the area with a larger local etching amount is located at the position where, when viewed from above, it sandwiches the upper wall 42 on the long wall portion 41A together with each of the exhaust ports 14 arranged along the X direction in the Y direction. Furthermore, at the end of the substrate G along the short side, the area with a larger local etching amount is located at the position where, when viewed from above, it sandwiches the upper wall 42 on the short wall portion 41B together with each of the exhaust ports 14 arranged along the Y direction in the X direction. In addition, by configuring the upper walls 42 in a manner corresponding to the exhaust ports 14 as described above, the eight upper walls 42 are moved away from the four corners of the lower wall 41. Furthermore, similarly to the exhaust ports 14, they are configured symmetrically with respect to both the imaginary line L1 and the imaginary line L2.

[0053] Furthermore, in this embodiment, the width L4 of the upper wall 42 is larger than the diameter L3 of the exhaust port 14. Additionally, the width L4 of the upper wall 42 refers to its length in the X direction for the upper wall 42 provided on the long wall portion 41A, and its length in the Y direction for the upper wall 42 provided on the short wall portion 41B. Based on the relationship between the diameter L3 and the width L4, if we observe the exhaust port 14 arranged along the X direction and the upper wall 42 corresponding to the exhaust port 14, then the ends P3 and P4 of the upper wall 42 in the X direction are located outwards relative to the ends P1 and P2 of the exhaust port 14 in the X direction. Furthermore, if we observe the exhaust port 14 arranged along the Y direction and the upper wall 42 corresponding to the exhaust port 14, then the ends P13 and P14 of the upper wall 42 in the Y direction are located outwards relative to the ends P11 and P12 of the exhaust port 14 in the Y direction.

[0054] Therefore, the upper wall 42 is configured such that each exhaust port 14 is completely shielded when viewed from the substrate G in the X and Y directions, respectively. This more reliably suppresses the aforementioned issue of a large supply of active species to the periphery of the substrate G due to the high flow rate of the etching gas. Furthermore, in this example, the width L4 is 850 mm.

[0055] In addition, the lower wall 41 is connected to the lifting mechanism 40 (see reference). Figure 1 When the conveying mechanism (not shown) transfers the substrate G onto the stage 21, the rectifier wall 4 is raised and separated from the stage 21, so that the transfer is performed without hindering the movement of the conveying mechanism. Alternatively, instead of raising or lowering the lower wall 41, a rotating mechanism is provided on the short wall portion 41B or the long wall portion 41A opposite to the conveying port 13, causing it to rotate in the vertical plane and retract from the position when the substrate G is being transported.

[0056] Furthermore, the etching apparatus 1 includes a control unit 10, which contains a program. The program is programmed with commands (step groups) that execute the processing of the substrate G in the order described later by sending control signals to various parts of the etching apparatus 1. Specifically, actions such as switching the high-frequency power supply 25 on and off, supplying etching gas from the gas supply source 32, raising and lowering the lifting pin 27 by the lifting mechanism 28, and raising and lowering the rectifier wall 4 by the lifting mechanism 40 are controlled by sending the aforementioned control signals. The program is stored, for example, on a storage medium such as an optical disc, hard disk, or DVD, and loaded into the control unit 10.

[0057] Next, the operation of the etching apparatus 1 will be described. When the substrate G is transported into the processing container 11 using a transport mechanism (not shown), the substrate G is placed on a mounting area on a temperature-adjusted stage 21 by means of a lifting pin 27. Then, the temperature of the substrate G is adjusted by means of a heat transfer gas supplied between the stage 21 and the substrate G, and the etching gas ejected from the nozzle 31 is exhausted in a vacuum atmosphere to achieve the desired pressure within the processing container 11. Then, the high-frequency power supply 25 is turned on, thereby plasmaifying the etching gas and supplying it to the substrate G, using the active species of the plasma to etch the Al film formed on the surface of the substrate G. The etching gas that does not contribute to the etching process of the substrate G and the reaction products generated by the etching flow out of the stage 21 through the exhaust ports 14 and are discharged from the processing container 11.

[0058] As described above, the flow-rectifying wall 4 is used to suppress the flow of etching gas toward the stage 21 at the peripheral end of the substrate G, thereby suppressing the supply of active species of the plasma. As mentioned earlier, by providing the upper wall 42, this effect is fully utilized in the area near the exhaust port 14 at the peripheral end of the substrate G, preventing locally high etching rates in that area. Therefore, etching with high uniformity is performed in all parts of the substrate G. Then, the supply of etching gas from the nozzle 31 is stopped, and the high-frequency power supply 25 is disconnected. Then, the substrate G is transferred to the conveying mechanism by means of the lifting pin 27 and sent out from the processing container 11.

[0059] Alternatively, the upper wall 42 can be fixed to the lower wall 41 in a non-removable manner, for example, using an adhesive. However, as mentioned above, considering that the areas with larger etching amounts vary depending on the processing conditions, it is preferable that the upper wall 42 is configured to be detachably fixed to the lower wall 41, and that the position of the upper wall 42 on the lower wall 41 can be changed. Figure 4An example is shown where the upper wall 42 is easily attached and detached using an adhesive piece 51. In this example, the adhesive piece 51, constituting the second connection portion, is adhered to the outer and / or inner sides of the rectifying wall 4 in a manner spanning the lower wall 41 and the upper wall 42. The adhesive piece 51 is fixed to the lower wall 41 and the upper wall 42 respectively by the adhesive force of the adhesive surface 52 formed on the adhesive piece 51. The adhesive surface 52 can be peeled off from the lower wall 41 and the upper wall 42, allowing for the aforementioned repositioning of the upper wall 42.

[0060] For the adhesive sheet 51, an adhesive sheet with adhesive surfaces 52 formed on both main surfaces of the substrate constituting the sheet can also be used. In this case, it can be fixed by contacting the upper surface of the lower wall 41 and the lower surface of the upper wall 42 with the adhesive surfaces 52 respectively. In order to fix it with sufficient strength, the thicknesses of the lower wall 41 and the upper wall 42 are appropriately adjusted to ensure that the areas of the upper surfaces of the lower wall 41 and the upper surfaces of the upper wall 42 that are bonded to each other are of sufficient size.

[0061] Furthermore, as mentioned above, Patent Document 3 illustrates a process for adjusting the various parts of the substrate G by varying the circumferential height of the rectifying wall. However, the rectifying wall in Patent Document 3 is composed of laterally arranged components. When replacing a component in one part to adjust the etching amount distribution of the substrate G, the connection between it and the adjacent components on the left and right is disconnected, and the new component is reconnected. That is, when changing a component in one part, it is necessary to disassemble and assemble it on both the left and right sides of that component. When changing components in multiple parts, the number of disassembly and assembly points becomes very large, leading to an increase in the operator's labor intensity. On the other hand, as described above... Figure 4 In this example, since the upper wall 42 can be freely attached to and detached from the lower wall 41, only the desired upper wall 42 needs to be attached to and detached and its position shifted, making the operation relatively easy. That is, based on the structure that allows the upper wall 42 to be freely attached to and detached from the lower wall 41, the distribution of the in-plane etching amount of the substrate G can be easily adjusted.

[0062] For a structure where the upper wall 42 can be easily disassembled and reassembled relative to the lower wall 41 and its position can be changed, further... Figure 5Other examples are shown. The lower end of the main surface of the upper wall 42 facing the outer periphery of the rectifier wall 4 is formed in such a way that it extends towards the outer periphery and then downwards, thereby forming a plate-shaped connecting portion 50 as the first connecting portion. The orientation of the main surface of the connecting portion 50 is the same as the orientation of the main surface of the upper wall 42. Moreover, through holes 53 and 54 are provided, respectively penetrating the connecting portion 50 and the lower wall 41 in the thickness direction. For example, a threaded portion is formed on the peripheral surface (inner wall of the through hole) of the through hole 54. By coinciding with the through holes 53 and 54, the threaded member 55 is inserted into the through holes 53 and 54 from the outer peripheral surface side of the rectifier wall 4 and screwed into the threaded portion of the peripheral surface of the through hole 54, thereby fixing the upper wall 42 relative to the lower wall 41. Alternatively, a threaded portion may be formed on the peripheral surface of the through hole 53, and the threaded member 55 may be inserted from the inner peripheral surface side of the rectifier wall 4 and screwed into the threaded portion of the peripheral surface of the through hole 53, thereby fixing the upper wall 42 relative to the lower wall 41. In this case, it is desirable to provide a countersunk hole (recess) at the opening of the through hole 54 to accommodate the head of the threaded member 55, thereby preventing the head of the threaded member 55 from protruding towards the substrate G side. The aforementioned screw engagement can be disengaged, thus allowing the upper wall 42 to be detached from the lower wall 41. Furthermore, in Figure 5 In this example, multiple through holes 53 are arranged laterally and close to each other on the upper wall 42. By selecting a through hole 53 from these multiple through holes 53 for inserting a threaded component 55, the position of the upper wall 42 relative to the lower wall 41 can be changed.

[0063] For the connecting portion that connects the lower wall 41 and the upper wall 42, the aforementioned connecting portion 50 is a structure that is integral with the upper wall 42 and independent of the lower wall 41, but as Figure 6 As shown in the diagram, the connecting portion 56 can also be a structure independent of both the upper wall 42 and the lower wall 41. The connecting portion 56 will be described focusing on its difference from the connecting portion 52. It is a plate-shaped member that extends from the main surface of the upper wall 42 to the main surface of the lower wall 41. Furthermore, each of these main surfaces refers to the main surface on the side that forms the outer peripheral surface of the flow-rectifying wall 4.

[0064] In the connecting portion 56, through holes 53 are formed on both the upper and lower sides. Furthermore, not only is a through hole 54 corresponding to the through hole 53 provided on the lower wall 41, but a through hole 54 corresponding to the through hole 53 is also provided on the upper wall 42. Thus, the through hole 53 on the upper side coincides with the through hole 54 on the upper wall 42, and the through hole 53 on the lower side coincides with the through hole 54 on the lower wall 41. Therefore, with… Figure 5 Similarly, the threaded part 55 is inserted into the overlapping through holes 53 and 54 from either the outer or inner circumferential surface of the rectifying wall 4. This fixes the lower wall 41 and upper wall 42 to the connecting part 56. In other words, the lower wall 41 and upper wall 42 are fixed to each other by means of the connecting part 56. Furthermore, for the upper wall 42, in... Figure 6The through holes 54 are shown in a configuration where only two are arranged laterally, but for example, more than two through holes 54 may be arranged laterally. Therefore, by selecting a through hole 54 from among these multiple through holes 54 for insertion of the threaded component 55, it is possible to achieve the desired connection. Figure 5 The example shown also adjusts the position of the upper wall 42. The through holes 54 in which no threaded part 55 is inserted are blocked by coinciding with the connection part 56.

[0065] In Figure 6 In the example shown, the connecting portion 56 can be considered as extending from the upper wall 42 toward the lower wall 41, or it can be considered as extending from the lower wall 41 toward the upper wall 42. Therefore, in Figure 5 , Figure 6 In the example shown, the structure is as follows: one of the upper wall 42 and the lower wall 41 has a connecting portion extending toward the other, which is connected to the other by means of a threaded component. Additionally, with Figure 5 Conversely, an example could be a structure where a connecting part 50 is fixed to and provided on the lower wall 41 and extends toward the upper wall 42, and the connecting part 50 is connected to the upper wall 42 by means of a threaded member 55.

[0066] exist Figure 7 The diagram shows another example of how the upper wall 42 and the lower wall 41 are detachably and securely fastened to each other by means of threaded fittings. A plurality of holes 57 are formed at intervals along the periphery of the lower wall 41, oriented perpendicular to the upper end face of the lower wall 41. The holes 57 open onto the upper surface of the lower wall 41 and, for example, have threads formed on their circumferential surfaces. Furthermore, a through hole 58 is provided vertically on the upper end face of the upper wall 42. The upper wall 42 is positioned on the lower wall 41 such that the through hole 58 coincides with any of the holes 57, and a long threaded fitting 59 is inserted from above the upper wall 42 and screwed into the threaded portion of the hole 57, thereby fixing the upper wall 42 to the lower wall 41. After this fixing, the screwing is released, the hole 57 for the long threaded fitting 59 is changed, and the screwing is re-engaged, thereby changing the position of the upper wall 42. Unused holes 57 in the fixing of the upper wall 42 and the lower wall 41 are preferably sealed with caps or the like.

[0067] Furthermore, as the upper wall 42, an example is shown where the height of the upper wall 42 is uniform when viewed along the perimeter of the lower wall 41, i.e., the height of the upper end is uniform. It is not limited to this shape; the upper wall 42 may also be configured such that its upper end has a varying height when viewed along its perimeter. As such an upper wall 42, in... Figure 8 An example of a mountain-shaped upper wall 42 is shown. Therefore, when the upper wall 42 is positioned on the long wall portion 41A, the height of the central portion in the X direction is greater; when it is positioned on the short wall portion 41B, the height of the central portion in the Y direction is greater. Furthermore, as for the upper wall 42, such as... Figure 9As shown, it can also be configured as a concave shape. Therefore, for this upper wall 42, when it is disposed on the long wall portion 41A, the height of the central portion in the X direction is smaller, and when it is disposed on the short wall portion 41B, the height of the central portion in the Y direction is smaller. The upper wall 42 is configured as follows... Figure 8 , Figure 9 This example demonstrates a structure with varying heights when viewed along the periphery of the lower wall 41, thereby enabling fine adjustments to the gas flow at different parts of the periphery of the substrate G, thus improving the uniformity of the processing at the periphery of the substrate G.

[0068] Furthermore, the arrangement and number of exhaust ports 14 are not limited to the examples described above. For instance, a total of four exhaust ports 14 could be provided, each located near a corner of the stage 21. Moreover, due to this arrangement of exhaust ports 14, the areas on the periphery of the substrate G where the etching amount is excessive without the upper wall 42 would become corners of the substrate G. In this case, instead of the aforementioned locations, upper walls 42 can be provided at each of the four corners of the lower wall 41. Therefore, the arrangement of the upper walls 42 is not limited to the examples described above. Figure 2 , Figure 3 The position is offset from the corner of the lower wall 41 as shown. Furthermore, the upper wall 42 is provided in a manner corresponding to areas with locally larger etching amounts; therefore, the number of upper walls 42 is not limited to eight, as long as they are provided in a manner corresponding to the number of areas. Furthermore, an example of applying this technology to an etching apparatus performing plasma processing is shown, but its application is not limited to such apparatuses; it can be applied to both film deposition apparatuses and substrate processing apparatuses that do not perform plasma processing. Moreover, it is not limited to factors such as the location of the exhaust port 14; it can also be applied to other factors such as the influence of the etching gas flow at the peripheral end of the substrate G caused by the action from the outer periphery of the stage 21, resulting in uneven etching rates.

[0069] Furthermore, the rectifying wall 4 is provided on the stage 21. To supplement the stage 21, it may include other components besides the component constituting the mounting surface of the substrate G (mounting surface forming component). These other components are those surrounding and connected to the mounting surface forming component. For example, in the aforementioned example, the mounting surface forming component is the lower electrode 22, and the other component is the annular component 23. In this case, the rectifying wall 4 can be provided on either the lower electrode 22 (which is the mounting surface forming component) or on the annular component 23 (which is another component). Alternatively, as described above, the rectifying wall 4 may be raised, lowered, or rotated relative to the stage 21. The rectifying wall 4 being provided on the stage 21 means that the rectifying wall 4 is located on the stage 21 at least when processing the substrate G.

[0070] In the aforementioned example, the upper end of the perimeter of the lower wall 41 has a uniform height, thus the upper wall 42 can be installed at any position on the perimeter. However, it is not limited to making the upper end of the perimeter uniform in this way; unevenness can also be formed. However, by making the upper end of the perimeter uniform, the upper wall 21 can be installed at all positions on the perimeter of the lower wall 41. That is, the degree of freedom in the installation position is high, which is advantageous. Furthermore, the shape of the substrate to be processed is not limited to the rectangular substrate in top view described above; it can also be circular. In this case, the lower wall 41 can also be set to be circular in top view, corresponding to the shape of the substrate.

[0071] Furthermore, the embodiments disclosed herein should be considered illustrative rather than restrictive in all respects. The above-described embodiments may also be omitted, substituted, modified, or combined in various ways without departing from the scope and spirit of the appended claims.

[0072] [Evaluation Test]

[0073] The evaluation test will now be described in detail. As evaluation test 1-1, without the upper wall 42, a rectifying wall consisting only of the lower wall 41 was used to etch the substrate G, and the etching amount of each portion was measured. Furthermore, for the substrate G used in this evaluation test, a patterned film (hereinafter referred to as a patterned film) was provided in a region extending 25 mm from its center to both the long and short sides of the substrate G. That is, the periphery of the substrate G formed a rectangular annular region (a rectangular frame-like region) without a patterned film, and the width of this annular region was 25 mm. Since the area where the patterned film was formed was limited, a small 50 mm square piece cut from the patterned film substrate for periphery measurement was placed at the periphery of the substrate G. The etching was performed on both the patterned film directly formed on the substrate G and the patterned film on the small piece, and the etching amount of each patterned film was measured.

[0074] The above-mentioned small piece configuration is in the form of Figure 3 In one of the four regions divided by the imaginary lines L1 and L2 shown, a small 50mm square piece is arranged between positions 15mm and 30mm from the long and short sides of the substrate G. That is, it is located between positions 15mm and 30mm from the periphery of the substrate G. Therefore, the measurement area measured using a patterned film directly formed on the substrate G and the measurement area measured using a patterned film formed on the small piece are partially overlapping.

[0075] Figure 10 The results of evaluation test 1-1 are shown, schematically illustrating the region (hereinafter referred to as the 1 / 4 region of substrate G) among the four regions divided by imaginary lines L1 and L2 into which small pieces are arranged. This 1 / 4 region of substrate G corresponds to... Figure 3 The lower right region, divided by imaginary lines L1 and L2, therefore, Figure 10 The lower right side of the image represents the corner of substrate G, and the upper left side represents the center of substrate G. The etching rate, obtained by standardizing the measurement results, is represented correspondingly to the measurement location where this etching rate was obtained. This etching rate is obtained by dividing the etching amount at one measurement location on substrate G by the average etching amount obtained from all measurement locations within the entire surface of substrate G. Therefore, the larger the standardized etching rate value, the larger the actual etching rate. Figure 10 In this process, patterns are marked on the measurement area according to the etching rate.

[0076] In the figure, a two-dotted line is used to separate the measurement area using a patterned film directly formed on the substrate G and the measurement area using a small piece of patterned film. Furthermore, the region from 15 mm from the long side of the substrate G towards the center of the substrate G to 30 mm from the center of the substrate G, and the region from 15 mm from the short side of the substrate G towards the center of the substrate G to 50 mm from the center of the substrate G, are defined as the outer peripheral region E, and are enclosed by a one-dotted line.

[0077] Such as Figure 10 As shown, in the outer peripheral region E, there are localized areas with higher etching rates between the center and corners of the substrate G along the long side direction (X direction). This region is denoted as G1. Specifically, in region G1, the etching rates obtained from the small piece at distances of 15 mm, 18 mm, 20 mm, 25 mm, and 30 mm from the long side of the substrate G are 1.08, 1.08, 1.07, 1.09, and 1.06, respectively, while the etching rate obtained from the patterned film directly formed on the substrate G is 1.06. Furthermore, in the outer peripheral region E, there are localized areas with relatively high etching rates between the center and corners of the substrate G along the short side direction (Y direction). This region is denoted as G2. Specifically, in region G2, the etching rates obtained from the small piece at distances of 15 mm, 18 mm, 20 mm, 25 mm, and 30 mm from the short side of the substrate G are 1.13, 1.09, 1.11, 1.09, and 1.07, respectively, while the etching rate obtained from the patterned film directly formed on the substrate G is 1.05. Regions G1 and G2 are described in the embodiment as regions with locally larger etching amounts at the peripheral edges of the substrate G.

[0078] Based on the measurement results of evaluation test 1-1, Uniformity, as an indicator of the deviation in etching amount, was calculated. Uniformity is expressed as a percentage: (maximum value - minimum value) / (maximum value + minimum value). The smaller the value, the higher the uniformity of the etching process. The Uniformity in the 1 / 4 region of substrate G is 13.9%, and the Uniformity in the outer peripheral region E of that 1 / 4 region is 15.1%.

[0079] As evaluation tests 1-2, in addition to using in Figures 1-3 Apart from the rectifier wall 4 located at the position described in the text, etching is performed in the same manner as in evaluation test 1-1, and the amount of etching is measured. Figure 11 The results of the evaluation tests 1-2 are shown, and compared with... Figure 10 Similarly, this is represented as 1 / 4 of the substrate G. As shown in the figure, compared to evaluation test 1-1, the etching rates of regions G1 and G2 are reduced. Specifically, in region G1, the etching rates obtained from the small piece at distances of 15mm, 18mm, 20mm, 25mm, and 30mm from the long side of the substrate G are 0.94, 0.94, 0.93, 0.93, and 0.97, respectively, while the etching rate obtained from the patterned film directly formed on the substrate G is 0.97. Moreover, in region G2, the etching rates obtained from the small piece at distances of 15mm, 18mm, 20mm, 25mm, and 30mm from the short side of the substrate G are 1.04, 1.06, 1.03, 0.99, and 1.00, respectively, while the etching rate obtained from the patterned film directly formed on the substrate G is 0.99.

[0080] In evaluation tests 1-2, the uniformity of the 1 / 4 region of substrate G was 11.7%, and the uniformity of the outer peripheral region E of the 1 / 4 region of substrate G was 7.7%, both lower than the values ​​in evaluation test 1-1. It is shown that by providing the upper wall 42 in this way, the uniformity value of the outer peripheral region E can be reduced, thereby reducing the uniformity value of substrate G up to the central portion. Therefore, evaluation test 1 demonstrates the effect of providing the upper wall 42 in improving the uniformity of the overall in-plane processing of substrate G.

Claims

1. A substrate processing apparatus, wherein, The substrate processing apparatus includes: A processing container that holds a substrate; A stage, disposed within the processing container, having a mounting area for mounting the substrate; A gas supply unit supplies processing gas to process a substrate placed in the mounting area. An exhaust port that vents air from the processing container; A lower wall, which is formed along the periphery of the placement area and disposed on the stage in a manner that surrounds the substrate; and An upper wall, which partially protrudes upward around the periphery of the lower wall and is formed independently relative to the lower wall, and the position of the upper wall on the lower wall is changeable.

2. The substrate processing apparatus according to claim 1, wherein, The substrate is rectangular when viewed from above. The lower wall includes two first wall portions facing each other and two second wall portions adjacent to and facing each other. The upper wall is provided to partially protrude upward from each of the first wall portions and each of the second wall portions.

3. The substrate processing apparatus according to claim 2, wherein, The lower wall has a consistent height along the upper end of its perimeter.

4. The substrate processing apparatus according to any one of claims 1 to 3, wherein, The upper wall can be freely assembled and disassembled relative to the lower wall.

5. The substrate processing apparatus according to claim 4, wherein, The substrate processing apparatus is provided with a first connecting portion, which is formed to extend from one of the upper wall and the lower wall to the other, and is connected to the other by a threaded member to fix the upper wall and the lower wall to each other.

6. The substrate processing apparatus according to claim 4, wherein, The substrate processing device is provided with a second connecting part, which fixes the upper wall and the lower wall to each other by being respectively bonded to the upper wall and the lower wall.

7. The substrate processing apparatus according to any one of claims 1 to 3, wherein, The height of the upper wall is constant when viewed along the perimeter of the lower wall.

8. The substrate processing apparatus according to any one of claims 1 to 3, wherein, The height of the upper wall changes when viewed along the perimeter of the lower wall.

9. The substrate processing apparatus according to any one of claims 1 to 3, wherein, The exhaust port opens upwards on the outer side of the platform. The upper wall is designed to separate the mounting area and the exhaust port when viewed from above.

10. A substrate processing method, wherein, The substrate processing method includes the following steps: The substrate is placed in the processing container; The substrate is placed on a placement area on a stage provided within the processing container; The air inside the processing container is vented through the exhaust port; The substrate on the stage is surrounded by a lower wall formed along the periphery of the placement area; Processing gas is supplied from the gas supply unit to process the substrate on the stage; as well as The flow of the processed gas from the substrate toward the exhaust port is restricted by utilizing the lower wall and an upper wall that protrudes upward locally around the lower wall and is formed independently relative to the lower wall, and by changing the position of the upper wall on the lower wall.

11. The substrate processing method according to claim 10, wherein, The upper wall is configured to separate the exhaust port from a location where the processing speed is locally higher at the periphery of the substrate, in the absence of the upper wall.

Images