Plasma processing apparatus and method of manufacturing semiconductor device

Abstract

The invention relates to a plasma processing apparatus and a method of manufacturing a semiconductor device. Plasma processing is performed in a substrate surface more uniformly. A plasma processing apparatus according to an embodiment includes: a processing chamber capable of processing a substrate; a stage which is provided in the processing chamber and on which a substrate can be placed; a plasma generation unit that generates plasma above the stage on which the substrate is placed; a first ring-shaped member disposed around the substrate placed on the stage and divided into a plurality of first ring-shaped member pieces arranged in the circumferential direction; and a first movement mechanism that moves the first annular member to a position concentric with the substrate by moving each of the plurality of first annular member pieces in the radial direction of the substrate, and relatively changes the horizontal distance between the end of the substrate and the inner end of the first annular member.

Description

Technical Field

[0001] Embodiments of the present invention relate to a plasma processing apparatus and a method for manufacturing a semiconductor device. Background Technology

[0002] During the manufacturing process of semiconductor devices, when plasma treatment is performed on the substrate, it is required that the substrate surface be uniformly treated. If the plasma treatment is uneven in the central and peripheral areas of the substrate, it can sometimes cause defects in semiconductor devices formed on the peripheral areas. Summary of the Invention

[0003] One embodiment aims to provide a plasma processing apparatus and a method for manufacturing a semiconductor device that can perform plasma processing more uniformly within a substrate surface.

[0004] The plasma processing apparatus of the embodiment includes: a processing chamber capable of processing a substrate; a worktable disposed in the processing chamber capable of holding the substrate; a plasma generation unit that generates plasma above the worktable on which the substrate is held; a first annular member disposed around the substrate placed on the worktable and divided into a plurality of first annular member pieces arranged in the circumferential direction; and a first moving mechanism that moves the first annular member to a position forming a concentric circle with the substrate by moving each of the plurality of first annular member pieces radially along the substrate, thereby changing the horizontal distance between the end of the substrate and the inner end of the first annular member. Attached Figure Description

[0005] Figure 1 This is a diagram schematically illustrating an example of the overall configuration of the plasma processing apparatus according to Embodiment 1.

[0006] Figures 2Aa to 2Bb This is a diagram showing the detailed configuration of the cover ring of the plasma processing apparatus according to Embodiment 1.

[0007] Figures 3A-3B This is a diagram illustrating the flow of the first movement control in the plasma processing apparatus according to Embodiment 1.

[0008] Figure 4 This is a diagram illustrating the in-plane uniformity of the sputtering process under the first movement control described in Implementation 1, whether or not it is performed.

[0009] Figure 5 This is a flowchart illustrating an example of the sputtering process steps in the plasma processing apparatus according to Embodiment 1.

[0010] Figure 6This is a diagram showing an example of the shape of the end of the cover ring plate in a plasma processing apparatus according to a variation of Embodiment 1.

[0011] Figure 7 This is a cross-sectional view schematically showing an example of the overall configuration of the plasma processing apparatus according to Embodiment 2.

[0012] Figures 8A-8B This is a top view showing the detailed configuration of the top ring of the plasma processing apparatus according to Embodiment 2.

[0013] Figures 9A-9B This is a diagram illustrating the flow of the first movement control in the plasma processing apparatus according to Embodiment 2.

[0014] Figures 10A-10B This is a diagram illustrating the flow of the second movement control in the plasma processing apparatus according to Embodiment 2.

[0015] Figure 11 This is a flowchart illustrating an example of the etching process steps in the plasma processing apparatus according to Embodiment 2.

[0016] Explanation of reference numerals in the attached figures

[0017] 1, 2…Plasma processing device; 11, 21…Processing chamber; 12, 22…Worktable; 13, 23…Plasma generation unit; 14a, 14b, 14c…Anti-adhesion plate; 15…Cover ring; 15a, 15b, 15c, 15d…Cover ring piece; 16, 36…First moving mechanism; 25…Edge ring; 26…Top ring; 27…Intermediate ring; 28…Base ring; 37…Second moving mechanism; 100, 200…Control unit; 122, 222…Placement surface; 152, 262, 271…End face; 154, 254…Rack and pinion gear. 154b, 157a…recessed portion, 154a, 157b…convex portion, 155a…first step portion (height difference portion), 155b…second step portion, 161…pinion, 261…first top ring, 261a~261d…first top ring piece, 264…end, 265…second top ring, 265a~265d…second top ring piece, 266, 266a~266d…movable portion, 267…first surface, 278, 278a~278d…stationary portion, 279…second surface, T…target material, W, Y…substrate, Ws, Ys…end. Detailed Implementation

[0018] Hereinafter, embodiments will be described in detail with reference to the accompanying drawings. Furthermore, the present invention is not limited to the embodiments described below. Additionally, the constituent elements in the following embodiments include those readily conceived by those skilled in the art or substantially the same.

[0019] (Implementation Method 1)

[0020] (Example of a plasma processing device)

[0021] Figure 1 This is a diagram schematically illustrating an example of the overall configuration of the plasma processing apparatus 1 according to Embodiment 1.

[0022] On the surface of the substrate W, which is the object of processing in the plasma processing apparatus 1 of Embodiment 1, a device layer, such as a three-dimensional non-volatile memory, is formed. Due to the stress of each layer formed during the manufacturing process of the device layer, warping occurs in the substrate W. To correct the warping of the substrate W, a predetermined film obtained by sputtering is formed on the back side of the substrate W. The plasma processing apparatus 1 of Embodiment 1 is configured as a sputtering apparatus for forming a predetermined film on the substrate W. Sputtering is an example of plasma processing.

[0023] like Figure 1 As shown, the plasma processing apparatus 1 includes a processing chamber 11 and a control unit 100.

[0024] The processing chamber 11 is a housing configured to accommodate the substrate W, which is to be processed.

[0025] A worktable 12 is disposed below the processing chamber 11. The worktable 12 has a mounting surface 122 for placing a substrate W. The substrate W, which is brought into the processing chamber 11, is placed on the mounting surface 122 with its back side facing upward. In addition, the worktable 12 has a flange-like portion 121 at its periphery. The worktable 12 functions as an anode electrode.

[0026] A plasma generation unit 13 for generating plasma P is provided above the worktable 12. The plasma generation unit 13 includes a cathode electrode 131 and a gas supply pipe 132.

[0027] The cathode electrode 131 is a circular plate-shaped component disposed in the upper part of the processing chamber 11, opposite to the worktable 12.

[0028] Gas supply piping 132 is connected to the upper surface of processing chamber 11. More specifically, the upstream end of gas supply piping 132 is connected to bottle B, and the downstream end is connected to the upper surface of processing chamber 11. Gas supplied from bottle B is introduced into processing chamber 11 from the upper surface of processing chamber 11. The gas introduced into processing chamber 11 is, for example, N2 gas and Ar gas.

[0029] Additionally, pump 17 is connected to processing chamber 11 via gate valve 18. Gate valve 18 and pump 17 are, for example, disposed diagonally below the worktable 12 on which substrate W is mounted. By opening and closing gate valve 18, the venting of atmosphere from processing chamber 11 via pump 17 can be started or stopped.

[0030] During the sputtering process, firstly, the substrate W is placed on the mounting surface 122 of the worktable 12 with its back side facing upwards. Pump 17 is activated and gate valve 18 is opened to purge the atmosphere from the processing chamber 11. Next, gas is supplied into the processing chamber 11 from bottle B. When a high voltage is applied via high-voltage power supply 140, plasma P is generated within the processing chamber 11.

[0031] The cathode electrode 131 holds a target material T, for example, primarily composed of silicon (Si). A high-voltage power supply 140 is connected to the target material T. When a plasma P is generated in the space within the processing chamber 11, cations in the plasma P collide with the target material T. Sputtered particles released from the target material T deposit onto the substrate W. As a result, a predetermined film is formed on the back side of the substrate W. The predetermined film is, for example, a silicon nitride film (SiN film).

[0032] Furthermore, at this time, sputtered particles not only accumulate on the substrate W, but also on the anti-adhesion plates 14a-14c and the cover ring 15, which will be described later. When the sputtering process is repeatedly performed, the target material T is consumed, and a layer of sputtered particles with a thickness corresponding to the amount of target material T consumed is formed on the anti-adhesion plates 14a-14c and the cover ring 15.

[0033] Conventionally, target lifetime is used as an indicator of the consumption of target material T. Target lifetime represents the consumption relative to the maximum usable amount of target material T. Target lifetime is calculated based on the cumulative power consumption since the target material T is replaced with a new one. For example, in the early stage of the target lifetime, the consumption of target material T is low. That is, the layer thickness of the sputtered particle layer formed on the anti-adhesion plates 14a-14c and the cover ring 15 is small. On the other hand, for example, in the late stage of the target lifetime, the consumption of target material T is high. That is, the layer thickness of the sputtered particle layer formed on the anti-adhesion plates 14a-14c and the cover ring 15 is large. When the target lifetime exceeds the end and exceeds a predetermined threshold relative to the usable amount, the target material T is replaced with a new one. The target lifetime of target material T is managed by the control unit 100.

[0034] The cover ring 15 is an annular member disposed around the substrate W placed on the mounting surface 122. The base material of the cover ring 15 is made of SUS (steel special use stainless steel) or the like. However, the material constituting the cover ring 15 is not limited to SUS. The cover ring 15 prevents sputtered particles released from the target material T from adhering to the components around the substrate W. The cover ring 15 is an example of the first annular member.

[0035] The cover ring 15 has a main surface 151 extending along the surface direction of the substrate W, and an end surface 152 extending downward from the end of the main surface 151 on the substrate W side. The end surface 152 of the cover ring 15 overlaps with the end Ws of the substrate W in the vertical direction. As a result, sputtered particles flying from the target material T toward the substrate W and particles in the processing chamber 11 are suppressed from entering the device layer formation surface side of the substrate W via the end Ws of the substrate W.

[0036] Furthermore, the cover ring 15 is divided circumferentially. Details will be described later. Each cover ring piece is connected to the first moving mechanism 16 on its lower surface 153. The lower end of the first moving mechanism 16 is supported by the lower surface of the processing chamber 11. Following instructions from the control unit 100, the first moving mechanism 16 moves each cover ring piece radially along the substrate W. This allows the cover ring 15 to be moved to a position concentric with the substrate W.

[0037] Anti-adhesion plates 14a and 14c prevent sputtered particles released from the target material T from adhering to the components within the processing chamber 11. Anti-adhesion plate 14a is a circular plate-shaped member mounted on an anti-adhesion plate support member 14s arranged to surround the cathode electrode 131. Anti-adhesion plates 14b and 14c are annular members. Anti-adhesion plate 14b is disposed below the cover ring 15. More specifically, anti-adhesion plate 14b is disposed between the upper surface of the flange-like portion 121 of the worktable 12 and the mounting surface 122 of the substrate W. Additionally, anti-adhesion plate 14c is disposed to the side of the cover ring 15. Anti-adhesion plate 14c extends upward from the side of the cover ring 15 along the inner wall of the processing chamber 11, arranged to surround the space above the worktable 12. Furthermore, it is not necessary for both anti-adhesion plates 14b and 14c to be disposed within the processing chamber 11; at least one of the anti-adhesion plates 14b and 14c may be disposed within the processing chamber 11.

[0038] Figures 2Aa to 2Bb This is a diagram showing the detailed configuration of the cover ring 15 provided in the plasma processing apparatus 1 according to Embodiment 1.

[0039] Figure 2Aa This is a top view showing the cover ring 15 positioned at a reference position. In this embodiment, the reference position refers to the position where the end face 152 of the cover ring 15 overlaps with the end face Ws of the substrate W placed on the mounting surface 122 in the vertical direction. On the other hand, Figure 2Ba This is a top view showing the state of the cover ring 15 after it has moved from a reference position to a position concentric with the substrate W. Additionally, Figure 2Ab as well as Figure 2Bb Each is Figure 2Aa AA line and Figure 2Ba A cross-sectional view at line BB.

[0040] like Figure 2Aa As shown, the cover ring 15 is divided into a plurality of cover ring pieces 15a to 15d arranged circumferentially. Each of the cover ring pieces 15a to 15d has an arc shape. Each of the cover ring pieces 15a to 15d is connected to the first moving mechanism 16a to 16d. The cover ring pieces 15a to 15d are an example of the first annular member piece.

[0041] The first moving mechanisms 16a-16d move the cover ring pieces 15a-15d each radially along the substrate W. Specifically, when the points on the outer periphery of each of the cover ring pieces 15a-15d are equally divided in the circumferential direction as points Xa-Xd, the first moving mechanisms 16a-16d move the cover ring pieces 15a-15d each along the direction connecting the center point CN of the substrate W with points Xa-Xd respectively. The direction connecting the center point CN with points Xa-Xd is radially along the substrate W, and is... Figure 2Aa The direction in which arrow DR points. At this point, the radial movement distance of the cover ring pieces 15a to 15d is the same for all cover ring pieces. Therefore, as... Figure 2Ba As shown, the cover ring 15 moves to a position concentric with the substrate W, and the horizontal distance between the end Ws of the substrate W and the end face 152 of the cover ring 15 changes accordingly. The first moving mechanisms 16a to 16d perform the above-described actions according to the instructions from the control unit 100.

[0042] Furthermore, the ends of the circumferentially adjacent cover rings 15a-15d are joined together by a labyrinthine structure. Specifically, for example, [the following is an example of...] Figure 2Ab The right end of each of the cover ring pieces 15a and 15b shown is designated as one end, and the left end is designated as the other end. Cover ring piece 15a has a first stepped portion 155a at one end, and cover ring piece 15b has a second stepped portion 155b at the other end. The first stepped portion 155a and the second stepped portion 156b are joined. That is, the first stepped portion 155a and the second stepped portion 155b overlap in the vertical direction.

[0043] Therefore, even if the cover ring pieces 15a and 15b move radially, that is, move in the direction that separates one end of the cover ring piece 15a from the other end of the cover ring piece 15b, as Figure 2Bb As shown, it is also possible to maintain the state in which the first step portion 155a of the cover ring 15a and the second step portion 155b of the cover ring 15b overlap in the vertical direction. As a result, it is possible to suppress the downward scattering of sputtered particles through one end of the cover ring 15a and the other end of the cover ring 15b.

[0044] Back Figure 1The control unit 100 controls each part of the plasma processing apparatus 1. The control unit 100 is configured as a computer equipped with a CPU (Central Processing Unit), ROM (Read Only Memory), and RAM (Random Access Memory), etc. (not shown), to control the plasma processing apparatus 1 as a whole. For example, the control unit 100 controls the aforementioned parts to perform sputtering processing on the substrate W. Additionally, for example, the control unit 100 performs a first movement control, causing the cover ring plates 15a-15d to move radially by instructing the first moving mechanisms 16a-16d. When performing the first movement control, the control unit 100 refers to the target lifetime of the target material T. The control unit 100 determines the amount of movement of the cover ring plates 15a-15d based on the target lifetime.

[0045] Next, use Figures 3A-3B as well as Figure 4 The process of the first movement control performed by the control unit 100 will be explained.

[0046] Figures 3A-3B This is a diagram illustrating the flow of the first movement control in the plasma processing apparatus 1 according to Embodiment 1. Figures 3A-3B The process of the first movement control performed on cover ring 15b, which is an example of cover ring 15a to 15d, is described below. Figure 3A It is a cross-sectional view showing the state near the cover ring 15b, which is positioned at the reference position, before the first movement control is executed. Figure 3B This is a cross-sectional view showing the state near the cover ring 15b immediately after the first movement control has been executed. Figure 3A , Figure 3B Both show the state of the target material T at the end of its target lifetime and before the substrate W is placed on the mounting surface 122.

[0047] in addition, Figure 4 This is a diagram illustrating the in-plane uniformity of the sputtering process under the first movement control described in Implementation 1, whether or not it is performed. Figure 4 The horizontal axis corresponds to the distance from the center of the substrate W. Figure 4 The vertical axis corresponds to the thickness of a predetermined film formed on the substrate W. Furthermore, the thickness of the predetermined film is expressed as a ratio to the thickness at a predetermined location near the center of the substrate W. That is, in Figure 4 The closer the longitudinal axis is to 100%, the more uniform the predetermined film is formed in the central and peripheral parts of the substrate W.

[0048] like Figure 3AAs shown, when the target lifetime is nearing its end, a sputtered particle layer Dp of, for example, thickness L2 is formed on the main surface 151 and end surface 152 of the cover ring 15b.

[0049] Assuming that sputtering is performed with the cover ring 15, including such a cover ring piece 15b, positioned in a reference position, then as follows Figure 4 As shown by the dashed lines, the thickness of the predetermined film formed on the outer periphery of the substrate W is significantly reduced. This is because the sputtered particle layer Dp of thickness L2 formed on the end face 152 of the cover ring 15b covers the end face Ws of the substrate W, thus hindering the formation of the predetermined film in the covered portion. If the film thickness at the outer periphery of the substrate W is reduced, the in-plane uniformity deteriorates, sometimes resulting in defects in the semiconductor device. Therefore, it is desirable to form a predetermined film of the same thickness as the central portion of the substrate W on the outer periphery. In other words, it is desirable to perform sputtering processing as uniformly as possible on both the central and outer periphery of the substrate W.

[0050] Therefore, the control unit 100 moves the cover ring 15b radially outward by an amount equivalent to the thickness L2. Specifically, first, the control unit 100 obtains the target lifetime of the target material T, and determines the thickness L2 of the sputtered particle layer Dp based on the obtained target lifetime. A table, created in advance by an operator or the like, representing the correspondence between target lifetime and the thickness of the sputtered particle layer Dp, is stored in a storage unit (not shown) of the control unit 100. Based on this table, the control unit 100 determines the thickness L2 of the sputtered particle layer Dp corresponding to the obtained target lifetime. The control unit 100 then determines the determined thickness L2 as the radial movement amount of the cover ring 15b.

[0051] For example, when the thickness L2 of the sputtered particle layer Dp is determined to be 0.75 mm, the control unit 100 controls the first moving mechanism 16b to move the cover ring 15b radially outward by 0.75 mm. Thus, as... Figure 3B As shown, the sputtered particle layer Dp formed on the end face 152 of the cap ring 15 no longer covers the end face Ws of the substrate W. As a result, the uniformity of the sputtering process within the substrate surface is improved, such as... Figure 4 As shown by the solid line, the reduction in the thickness of the predetermined film at the outer periphery of the substrate W is suppressed.

[0052] Furthermore, the control unit 100 may not need to calculate the thickness L2 of the sputtered particle layer Dp. For example, a table specifying the relationship between the target lifetime and the target position of the cover ring 15b is stored in a storage unit (not shown) of the control unit 100. The control unit 100 may also determine the target position of the cover ring 15b based on the obtained target lifetime and the table, and move the cover ring 15b to the determined target position.

[0053] Here, use Figure 3A , Figure 3BThe detailed configuration of the first moving mechanism 16 will be described. The first moving mechanism 16b is connected to the cover ring 15b.

[0054] like Figure 3A , Figure 3B As shown, a rack gear 154, which is a spur gear with an infinitely large diameter, is provided on the lower surface 153 of the cover ring plate 15b.

[0055] The first moving mechanism 16b includes a pinion 161 that meshes with a rack and pinion 154 and a bevel gear 162 that meshes with and drives the pinion 161. The first moving mechanism 16b also includes a shaft 163 extending in the vertical direction and an actuator 164 connected to the lower end of the shaft 163. The bevel gear 162 is connected to the upper end of the shaft 163. The actuator 164 rotates the bevel gear 162 by rotating the shaft 163. Furthermore, the pinion 161 is connected to a rotating shaft 161b extending in the circumferential direction. The pinion 161 rotates radially about the rotating shaft 161b by the rotation of the bevel gear 162.

[0056] The rack and pinion 154 has alternating rows of protrusions 154a and recesses 154b. The protrusions 154a and recesses 154b are arranged in a radial direction along the substrate W. With this configuration, the first moving mechanism 16b can move the cover ring 15b along the radial direction along the substrate W, i.e., along... Figure 3B Move in the direction that arrow DR is pointing.

[0057] (Semiconductor device manufacturing method)

[0058] exist Figure 5 The process of sputtering, which is part of the manufacturing method of the semiconductor device in Embodiment 1, will be described.

[0059] Figure 5 This is a flowchart illustrating an example of the sputtering process steps in the plasma processing apparatus 1 according to Embodiment 1. The first movement control described above is performed as part of the sputtering process.

[0060] A device layer, such as a three-dimensional non-volatile memory, is formed on the surface of the substrate W of the plasma processing apparatus 1 in Embodiment 1.

[0061] The control unit 100 controls a transfer arm (not shown) to move the substrate W into the processing chamber 11 with its back side facing upward (S11). Next, the control unit 100 controls the transfer arm to place the substrate W on the mounting surface 122 of the worktable 12 (S12). A cover ring 15 is disposed around the substrate W placed on the mounting surface 122.

[0062] The control unit 100 obtains the target lifetime of the target material T (S13).

[0063] Based on the target lifetime, the control unit 100 determines the thickness L2 of the sputtered particle layer Dp formed on the cap ring 15, and determines an amount equivalent to the thickness L2 as the radial movement amount of the cap ring 15 (S14).

[0064] The control unit 100 controls the first moving mechanisms 16a to 16d according to the determined amount of movement, causing the cover ring pieces 15a to 15d to move radially along the substrate W. As a result, the cover ring 15 moves to a position concentric with the substrate W, and the horizontal distance between the end point Ws of the substrate W and the inner end face 152 of the cover ring pieces 15a to 15d changes (S15). Furthermore, the processes S13 and S14 can be performed at any time until the start of the process S15.

[0065] The control unit 100 controls the plasma generation unit 13 to generate plasma P and form a predetermined film on the substrate W (S16).

[0066] When the formation of the predetermined film is completed, the control unit 100 controls the transfer arm (not shown) to remove the substrate W from the processing chamber 11 (S17). As described above, the sputtering process of Embodiment 1 is completed.

[0067] (Summary)

[0068] The plasma processing apparatus 1 of Embodiment 1 includes: a worktable 12 capable of holding a substrate W; a plasma generation unit 13 for generating plasma; a cover ring 15 disposed around the substrate W and divided into a plurality of first annular member pieces arranged circumferentially; and a first moving mechanism 16. The first moving mechanism 16 moves the plurality of first annular member pieces radially along the substrate W, thereby moving the cover ring 15 to a position concentric with the substrate W, and causing the distance in the horizontal direction between the end point Ws of the substrate W and the inner end face 152 of the cover ring 15 to change relatively.

[0069] Therefore, in a sputtering apparatus, even if a sputtering particle layer Dp is formed on the inner end face 152 of the cover ring 15, by moving the cover ring 15 to a position concentric with the substrate W, it is possible to prevent the top of the end Ws of the substrate W from being covered by the sputtering particle layer Dp. As a result, sputtering processing can be performed more uniformly from the center of the substrate W to its outer periphery.

[0070] In addition, the cover ring 15 is divided into four cover ring pieces 15a to 15d, and the ends of the cover ring pieces that are adjacent in the circumferential direction are joined together by a labyrinth structure.

[0071] Therefore, even when the four cover rings 15a to 15d are moved radially outward along the substrate W, the ends of adjacent cover rings remain overlapping each other in the vertical direction. As a result, it is possible to suppress the downward scattering of sputtered particles generated in the processing chamber 11 between the ends of adjacent cover rings.

[0072] (Modified Example)

[0073] use Figure 6 A variation of Embodiment 1 will be described below. In the plasma processing apparatus of the variation, the shapes of the ends of the four cover ring plates 15a to 15d are different from those of Embodiment 1 described above. Furthermore, hereafter, the same reference numerals will sometimes be used to refer to the same components as in the embodiment described above, and their descriptions will be omitted.

[0074] Figure 6 This is a diagram showing an example of the shape of the ends of the cover ring plates 15a to 15d in a plasma processing apparatus according to a variation of Embodiment 1. Figure 6 Is with Figure 2Ab The corresponding diagram.

[0075] like Figure 6 As shown, the cover ring 15a has a recess 157a at one end, and the cover ring 15b has a protrusion 157b at the other end. The recess 157a of the cover ring 15a and the protrusion 157b of the cover ring 15b overlap in the vertical direction.

[0076] Therefore, even if the cover ring plates 15a and 15b move radially outward due to the first movement control described above, the recess 157a of the cover ring plate 15a and the protrusion 157b of the cover ring plate 15b can be maintained in a state of overlapping in the vertical direction. As a result, sputtered particles, such as those passing between the cover ring plates 15a and 15b, can be suppressed from scattering downward.

[0077] The plasma processing apparatus according to Modified Example 1, in addition to the above, also has the same effects as the plasma processing apparatus 1 of the above embodiment.

[0078] (Implementation Method 2)

[0079] use Figures 7-11 The second implementation method will be described below.

[0080] In the plasma processing apparatus 2 of Embodiment 2, the apparatus configuration and the type of substrate to be processed differ from those of Embodiment 1 described above. Hereinafter, the same reference numerals will sometimes be used to refer to the same configurations as in the embodiments described above, and their descriptions will be omitted.

[0081] Figure 7This is a cross-sectional view schematically illustrating an example of the overall configuration of the plasma processing apparatus 2 according to Embodiment 2. Furthermore, for ease of explanation, in Figure 7 Sometimes, the first moving mechanism 36 and other components that are not included in the same cross-section as the other components are also shown.

[0082] In the plasma processing apparatus 2 of Embodiment 2, a lower layer film for etching and a resist film serving as a mask are formed on the substrate Y to be processed. The plasma processing apparatus 2 of Embodiment 2 is configured as an etching apparatus that performs etching processing on the lower layer film using the resist film as a mask. In this embodiment, the etching process is an example of plasma processing.

[0083] like Figure 7 As shown, the plasma processing apparatus 2 includes a processing chamber 21 and a control unit 200.

[0084] The processing chamber 21 is a housing configured to accommodate the substrate Y, which is to be processed.

[0085] A worktable 22 is disposed within the processing chamber 21. The worktable 22 is supported on a support portion 223 that protrudes vertically upward in a cylindrical shape from the bottom wall near the center of the processing chamber 21. The worktable 22 has a mounting surface 222 capable of holding a substrate Y. The substrate Y, which is brought into the processing chamber 21, is placed on the mounting surface 222 with its surface facing upward. In addition, the worktable 22 has a flange-like portion 221 at its periphery.

[0086] A power supply line 41 for supplying high-frequency power is connected to the worktable 22. A DC blocking condenser 42, a matching circuit 43, and a high-frequency power supply 44 are connected to the power supply line 41. High-frequency power of a predetermined frequency is supplied to the worktable 22 from the high-frequency power supply 44. That is, the worktable 22 functions as the lower electrode.

[0087] A plasma generation unit 23 for generating plasma is provided above the workbench 22. The plasma generation unit 23 includes a gas supply port 231 located near the upper part of the processing chamber 21 and a spray head 233 located below the gas supply port 231.

[0088] A gas supply device (not shown) is connected via piping to gas supply port 231 to supply the processing gas used in the etching process.

[0089] The spray head 233 functions as the upper electrode. Multiple gas flow paths 232 extending through the thickness of the plate are provided in the spray head 233. Processing gas supplied from the gas supply port 231 is introduced into the processing chamber 21 via the gas flow paths 232. When a high-frequency voltage is applied to the worktable 22, which serves as the lower electrode, with the spray head 233 grounded, plasma is generated above the worktable 22.

[0090] A baffle plate 38 is provided between the side wall of the processing chamber 21 and the worktable 22. The baffle plate 38 has a plurality of gas exhaust holes 38e extending through the thickness direction of the plate.

[0091] A gas exhaust port 31 is provided in the processing chamber 21, which is located below the baffle 38. The gas exhaust port 31 is connected to a vacuum pump (not shown) via piping. The vacuum pump is capable of venting the atmosphere inside the processing chamber 21.

[0092] An edge ring 25 is disposed around the substrate Y placed on the mounting surface 222. The edge ring 25 includes an intermediate ring 27 disposed above the flange-like portion 221 of the worktable 22 and a top ring 26 disposed above the intermediate ring 27. Both the top ring 26 and the intermediate ring 27 are annular components made of quartz, silicon, or the like. Furthermore, the materials constituting the top ring 26 or the intermediate ring 27 are not limited to these. The top ring 26 has the following function: during the etching process of the substrate Y, it is adjusted so that the electric field (outermost peripheral sheath layer distribution) applied to the periphery of the substrate Y is not deflected relative to the vertical direction perpendicular to the surface of the substrate Y.

[0093] The top ring 26 is configured such that its radially inner end face 262 overlaps with the radially inner end face 271 of the intermediate ring 27 in the vertical direction. Furthermore, the radial width of the top ring 26 is greater than the radial width of the intermediate ring 27. Therefore, the top ring 26 protrudes radially outward compared to the intermediate ring 27. End face 262 is an example of an end face.

[0094] A base ring 28 is disposed below the outer end 264 of the top ring 26. The base ring 28 is also a ring-shaped component made of quartz, silicon, or the like.

[0095] Furthermore, the top ring 26 is divided circumferentially. Details will be described later. Each top ring piece is connected to the first moving mechanism 36 at its lower surface 263. The first moving mechanism 36 passes through the base ring 28 and is connected to the support portion 223 of the worktable 22. Following instructions from the control unit 200, the first moving mechanism 36 moves each top ring piece radially along the substrate Y. This moves the top ring 26 to a position concentric with the substrate Y.

[0096] Furthermore, the intermediate ring 27 is connected to the second moving mechanism 37 at its lower surface 273. The second moving mechanism 37 includes an actuator 374 disposed on the support portion 223 and a pin 375 that passes through the actuator 374 through the worktable 22 and abuts against the lower surface 273 of the intermediate ring 27. The pin 375 is configured to move up and down by the operation of the actuator 374. The second moving mechanism 37 moves the pin 375 up and down according to the instruction from the control portion 200, thereby moving the intermediate ring 27 and the top ring 26 disposed above the intermediate ring 27 in the vertical direction.

[0097] Figure 8A as well as Figure 8B This is a top view showing the detailed configuration of the top ring 26 included in the plasma processing apparatus 2 according to Embodiment 2. For ease of explanation, in Figure 8A as well as Figure 8B The substrate Y, which is placed on the mounting surface 222, is also shown in the figure.

[0098] Figure 8A This is a top view showing the top ring 26 in its reference position before it moves radially and vertically. In this embodiment, the reference position refers to the position where the end face 262 of the top ring 26 is positioned opposite the end face Ys of the substrate Y, separated by a distance L3. On the other hand, Figure 8B This is a top view showing the state in which the end face 262 of the top ring 26 is positioned relative to the end Ys of the substrate Y, separated by a distance L4, as the top ring 26 moves radially and vertically.

[0099] like Figure 8A As shown, the top ring 26 includes four first top ring pieces 261a-261d arranged circumferentially and four second top ring pieces 265a-265d arranged alternately with the first top ring pieces 261a-261d in the circumferential direction. The first top ring pieces 261a-261d are examples of first annular member pieces, and the four second top ring pieces 265a-265d are examples of second annular member pieces. Furthermore, the top ring 26 is an example of a third annular member.

[0100] The first top ring plates 261a to 261d are arranged at predetermined intervals around the substrate Y placed on the mounting surface 222. Each of the first top ring plates 261a to 261d has an end face 262a to 262d facing inward. Figure 8A In the middle, end faces 262a to 262d are opposite to the end face Ys of the substrate Y at a distance L3. End faces 262a to 262d are part of the end face 262 of the top ring 26. The first top ring pieces 261a to 261d are each connected to the first moving mechanisms 36a to 36d.

[0101] Furthermore, the portion of the top ring 26 that is composed of the first top ring pieces 261a to 261d that are divided in the circumferential direction is sometimes referred to as the first top ring 261.

[0102] like Figure 8B As shown, the first moving mechanisms 36a to 36d move the first top ring pieces 261a to 261d each radially along the substrate Y, thereby moving the first top ring 261 to a position concentric with the substrate Y. As a result, the end Ys of the substrate Y and the end faces 262a to 262d can be positioned opposite each other, for example, at a distance L4.

[0103] Second top ring plates 265a to 265d are arranged between adjacent first top ring plates in the circumferential direction among the first top ring plates 261a to 261d. That is, the first top ring plates 261a to 261d and the second top ring plates 265a to 265d are arranged alternately in the circumferential direction.

[0104] like Figure 8A As shown, the second top ring plates 265a to 265d are each radially divided into movable portions 266a to 266d and immovable portions 278a to 278d.

[0105] Movable portions 266a to 266d are disposed radially inward. Each of the movable portions 266a to 266d is connected to the second moving mechanism 37a to 37d. The movable portions 266a to 266d are configured to move vertically via the second moving mechanism 37a to 37d. Furthermore, the movable portions 266a to 266d have first surfaces 267a to 267d facing radially inward. The first surfaces 267a to 267d are disposed at a distance L3 from the end Ys of the substrate Y. The first surfaces 267a to 267d are part of the end face 262 of the top ring 26.

[0106] The stationary portions 278a to 278d are disposed outside the movable portions 266a to 266d. The stationary portions 278a to 278d have a second surface 279a to 279d facing radially inward. The second surface 279a to 279d is disposed at a position that is a distance L4 from the end Ys of the substrate Y, which is longer than the distance L3.

[0107] Details will be used Figures 10A-10B As described later, when the movable parts 266a to 266d move downward from the reference position via the second moving mechanism 37a to 37d, the second surfaces 279a to 279d of the stationary parts 278a to 278d are exposed, and the second surfaces 279a to 279d are opposite to the end Ys of the substrate Y. That is, the second surfaces 279a to 279d can also become part of the end surface 262 of the top ring 26.

[0108] Additionally, as mentioned above, the intermediate ring 27 (refer to...) Figure 7The middle ring 27 is positioned below the top ring 26 in an overlapping manner. Although not shown in the figure, the middle ring 27 is also divided in the thickness direction at a position where it overlaps with the top ring 26 in the vertical direction along the circumferential and radial division points. Thus, the top ring 26 and the middle ring 27 can be partially linked.

[0109] Furthermore, the portion of the top ring 26 composed of the second top ring pieces 265a to 265d is sometimes referred to as the second top ring 265.

[0110] The control unit 200 controls each part of the plasma processing apparatus 2. The hardware configuration of the control unit 200 is the same as that of the control unit 100, therefore its description is omitted here. In this embodiment, the control unit 200 controls each of the above-mentioned parts to perform etching processing on the substrate Y. Additionally, for example, the control unit 200 performs a first movement control: moving the first top ring 261 to a position concentric with the substrate Y by instructing the first moving mechanism 36. Additionally, for example, the control unit 200 performs a second movement control: moving the movable parts 266a-266d of the second top ring 265 in the vertical direction by instructing the second moving mechanisms 37a-37d.

[0111] As described above, the top ring 26 has the function of adjusting the electric field (outermost peripheral sheath distribution) applied to the periphery of the substrate Y during etching. By adjusting the outermost peripheral sheath distribution, the oblique incidence of ions relative to the periphery of the substrate Y is suppressed, resulting in more uniform etching at the outer periphery and center of the substrate Y. However, the outermost peripheral sheath distribution sometimes varies depending on the type of the underlying film and the shape of the pattern. Therefore, it is necessary to adjust the outermost peripheral sheath distribution according to the type of the underlying film and the shape of the pattern. The outermost peripheral sheath distribution can be adjusted by varying the horizontal distance between the end Ys of the substrate Y and the end face 262 of the top ring 26.

[0112] For example, the operator determines the optimal position of the top ring 26 relative to the end Ys of the substrate Y based on the type of the lower layer film and the shape of the pattern, and pre-registers this as an etching condition in the recipe. The recipe is stored in the storage unit of the control unit 200. When the recipe is loaded, the control unit 200 performs the first and second movement controls according to the etching conditions registered in the recipe. As a result, the optimal outermost sheath layer distribution corresponding to the type of the lower layer film and the shape of the pattern can be obtained.

[0113] Here, use Figures 9A-9B as well as Figures 10A-10B The process of the first and second movement control performed by the control unit 200 will be explained.

[0114] Figures 9A-9BThis is a diagram illustrating the flow of the first movement control in the plasma processing apparatus 2 according to Embodiment 2. Figure 9A It is shown Figure 8A A cross-sectional view of the state near the first top ring 261 at the CC line. On the other hand, Figure 9B It is shown Figure 8B A cross-sectional view of the state near the first top ring 261 at the EE line.

[0115] like Figure 9A As shown, a rack and pinion 254 is provided on the lower surface 263 of the first top ring 261b. The rack and pinion 254 meshes with the upper end of the first moving mechanism 36b extending through the base ring 28. Furthermore, the first moving mechanism 36b has a function for use with... Figure 3A , Figure 3B The configuration of the first moving mechanism 16, which has already been explained, will not be described in detail here.

[0116] For example, if condition 2 is registered as an etching condition in the manufacturing process, such as Figure 9A As shown, the control unit 200 controls the first moving mechanism 36b to position the first top ring plate 261b at a reference position. At the reference position, the end face 262b of the first top ring plate 261b is opposite to the end face Ys of the substrate Y in the horizontal direction at a distance L3.

[0117] On the other hand, for example, if the first condition is registered in the manufacturing process as an etching condition, such as Figure 9B As shown, the control unit 200 controls the first moving mechanism 36b to move the first top ring plate 261b radially outward. As a result, the horizontal distance between the end face 262b of the first top ring plate 261b and the end Ys of the substrate Y is relatively expanded, for example, they can be separated by a distance L4.

[0118] Figure 10A as well as Figure 10B This is a diagram illustrating the flow of the second movement control in the plasma processing apparatus 2 according to Embodiment 2. Specifically, Figure 10A It is shown Figure 8A A cross-sectional view of the state near the second top ring 265 at the DD line. Figure 10B It is shown Figure 8B A cross-sectional view of the state near the second top ring 265 at the FF line.

[0119] The lower surface 273 of the intermediate ring 27, which overlaps with the movable part 266b of the second top ring 265b in the vertical direction, abuts against the pin 375 of the second moving mechanism 37b. By moving the pin 375 up and down, the movable part 266b and the intermediate ring 27 move in conjunction in the vertical direction.

[0120] For example, if condition 2 is registered as an etching condition in the manufacturing process, such as Figure 10A As shown, the control unit 200 controls the second moving mechanism 37b to position the movable part 266b at a first height position, which serves as a reference position. The first height position refers to the height position where the first surface 267b of the movable part 266b is opposite to the end point Ys of the substrate Y. At the first height position, the first surface 267b of the movable part 266b is opposite to the end point Ys of the substrate Y at a distance L3.

[0121] For example, if the first condition is registered as an etching condition in the manufacturing process, such as Figure 10B As shown, the control unit 200 controls the second moving mechanism 37b to move the movable part 266b to a second height position lower than the first height position. When the movable part 266b moves to the second height position, the second surface 279b of the stationary part 278b is exposed, and the second surface 279b faces the end Ys of the substrate Y. As a result, the second top ring plate 265b faces the end Ys of the substrate Y at a distance L4.

[0122] (Semiconductor device manufacturing method)

[0123] exist Figure 11 In this paper, the etching process, which is part of the manufacturing method of the semiconductor device in Embodiment 2, will be described.

[0124] Figure 11 This is a flowchart illustrating an example of the etching process steps in the plasma processing apparatus 2 according to Embodiment 2. The first and second movement controls described above are performed as part of the etching process.

[0125] On the surface of the substrate Y of the plasma processing apparatus 2 in Embodiment 2, for example, an etchable lower layer film and a resist film serving as a mask are formed.

[0126] When the substrate is loaded into the plasma processing apparatus 2, the control unit 200 controls a transfer arm (not shown) to move the substrate Y into the processing chamber 21 (S21). Next, the control unit 200 controls the transfer arm to place the substrate Y on the placement surface 222 of the worktable 22 (S22). A top ring 26 and an intermediate ring 27 are arranged around the substrate Y. At this time, the first top ring 261 and the second top ring 265 are, for example, arranged at a reference position.

[0127] The control unit 200 determines whether the first condition has been registered in the loading process (S23).

[0128] When the control unit 200 determines that the first condition has been registered in the manufacturing process (S23: Yes), the control unit 200 controls the first moving mechanism 36a-36d to move the first top ring 261 radially outward, thereby changing the horizontal distance between the first top ring 261 and the end Ys of the substrate Y (S24). Additionally, the control unit 200 controls the second moving mechanism 37a-37d to move the movable portions 266a-266d of the second top ring 265 to a second height position, thereby changing the horizontal distance between the second top ring 265 and the end Ys of the substrate Y (S25).

[0129] Furthermore, the processes in S23 and S24 can be performed at any time until the process in S25 begins. Additionally, if the control unit 200 determines that the first condition is not registered in the manufacturing process (S23: No), that is, if it determines that the second condition is registered in the manufacturing process, it controls the first moving mechanisms 36a-36d and the second moving mechanisms 37a-37d to position the first top ring 261 and the second top ring 265 at their respective reference positions (S26).

[0130] The control unit 200 controls the plasma generation unit 23 to generate plasma and etch the substrate Y (S27).

[0131] When the etching of substrate Y is completed, the control unit 200 controls a conveyor arm (not shown) to remove substrate Y from the processing chamber 21 (S28). As described above, the etching process of Embodiment 2 is completed.

[0132] (Summary)

[0133] The plasma processing apparatus 2 of Embodiment 2 includes a top ring 26 comprising a first top ring 261 divided in the circumferential direction and a second top ring 265 arranged alternately with the first top ring 261 in the circumferential direction. The first top ring 261 is configured to be able to move radially to a position concentric with the substrate Y. The second top ring 265 is divided into a movable portion 266 having a first surface 267 facing radially inward and a stationary portion 278 disposed outside the movable portion 266 and having a second surface 279 facing radially inward. The movable portion 266 is configured to be able to move along a direction intersecting the substrate surface of the substrate Y to a first height position or a second height position lower than the first height position. The stationary portion 278 is fixed at the first height position.

[0134] In Embodiment 2, the plasma processing apparatus 2 performs a first movement control that moves the first top ring 261 to a position concentric with the substrate Y. This changes the distance between the end Ys of the substrate Y and the first top ring 261. Additionally, a second movement control is performed by moving the movable portion 266 of the second top ring 265 to a first height position or a second height position, causing either the first surface 267 or the second surface 279, which is located outside the first surface 267, to face the end Ys of the substrate Y. This also changes the distance between the end Ys of the substrate Y and the second top ring 265.

[0135] In this way, by performing first and second movement controls on the first top ring 261 and the second top ring 265 respectively, the horizontal distance between the end Ys of the substrate Y and the end of the top ring 26 is relatively varied. As a result, the distribution of the outermost sheath layer is adjusted, and thus, etching can be performed more uniformly within the surface of the substrate Y. As a result, for example, shape defects in the pattern at the outer periphery of the substrate Y can be suppressed.

[0136] Furthermore, the outermost sheath layer distribution varies depending on the type of substrate Y. Etching conditions that determine the optimal distance between substrate Y and the second top ring 265 are pre-registered in the manufacturing process according to the type of substrate Y. During the manufacturing process, the control unit 200 determines the execution of the first and second movement controls based on the etching conditions registered in the manufacturing process. By adjusting the outermost sheath layer distribution according to the type of substrate Y, stable etching processing can be performed on various substrates.

[0137] Several embodiments of the present invention have been described, but these embodiments are merely illustrative and not intended to limit the scope of the invention. These new embodiments can be implemented in a wide variety of other ways, and various omissions, substitutions, and modifications can be made without departing from the spirit of the invention. These embodiments and their variations are included within the scope and spirit of the invention, and are included within the scope of the invention as described in the claims and its equivalents.

Claims

1. A plasma processing apparatus, comprising: The processing chamber is capable of processing the substrate; A worktable, disposed within the processing chamber, is capable of holding the substrate; The plasma generation unit generates plasma above the worktable on which the substrate is placed. The first annular member is arranged around the substrate placed on the worktable and is divided into a plurality of first annular member pieces arranged in the circumferential direction. as well as The first moving mechanism moves the first annular member to a position that forms a concentric circle with the substrate by moving each of the plurality of first annular member pieces radially along the substrate, thereby changing the horizontal distance between the end of the substrate and the inner end of the first annular member.

2. The plasma processing apparatus according to claim 1, The ends of the circumferentially adjacent first annular member pieces are joined together by a labyrinthine structure.

3. The plasma processing apparatus according to claim 2, The plurality of first annular member plates have racks and pinions arranged radially. The first moving mechanism, It has a pinion gear connected to a rotating shaft extending circumferentially and is capable of rotating radially about the rotating shaft. The plurality of first annular component plates move along the radial direction by meshing with the pinion through the rack and pinion.

4. The plasma processing apparatus according to claim 1, further comprising: The target material is disposed in the upper part of the processing chamber; and The control unit determines the amount of movement of the first annular member based on the target lifetime, which represents the amount of target material consumed due to sputtering by the plasma, and controls the first moving mechanism based on the determined amount of movement.

5. The plasma processing apparatus according to claim 1, further comprising: The target material is disposed in the upper part of the processing chamber; and An anti-adhesion plate, disposed on at least one side of the first annular member and below the first annular member, prevents sputtered particles from the target material sputtered by the plasma from accumulating in the processing chamber.

6. The plasma processing apparatus according to claim 1, further comprising: A plurality of second annular member pieces are arranged alternately with the plurality of first annular member pieces in the circumferential direction; and The second moving mechanism causes each of the plurality of second annular member pieces to move along a direction intersecting the substrate surface of the substrate. Each of the plurality of second annular component pieces includes: A movable part has a first surface facing radially inward, and is movable between a first height position opposite to an end of the substrate and a second height position lower than the first height position; and a stationary part is disposed outside the movable part at the first height position, and has a second surface facing radially inward. The second moving mechanism, The movable part is moved to either the first height position or the second height position so that either the first surface or the second surface is opposite to the end of the substrate, thereby changing the distance between the end of the substrate and the second annular member piece in the horizontal direction.

7. The plasma processing apparatus according to claim 6, The plasma processing device includes a control unit. The control unit, It is configured to perform etching processing on the substrate using the plasma. When the etching process is performed under the first condition, the following control is executed: the movable part is moved to the second height position by controlling the second moving mechanism so that the end of the substrate faces the second surface, and the plurality of first annular member pieces are moved to the radial outer side of the substrate by controlling the first moving mechanism.

8. The plasma processing apparatus according to claim 7, The control unit, When the etching process is performed under the second condition, the following control is executed: the movable part is moved to the first height position by controlling the second moving mechanism so that the end of the substrate is opposite to the first surface, and the first moving mechanism is controlled to move the first annular member to the radial inner side of the substrate.

9. A method for manufacturing a semiconductor device, The substrate is moved into a processing chamber capable of processing the substrate. The substrate is placed on a worktable, which is disposed within the processing chamber and capable of holding the substrate. A first annular member is arranged around the substrate placed on the worktable. By moving the first annular member to a position concentric with the substrate, the horizontal distance between the end of the substrate and the inner end of the first annular member becomes different. Plasma is supplied to the processing chamber from a plasma generation unit located at the top of the processing chamber.

10. The method for manufacturing a semiconductor device according to claim 9, When the first annular member is arranged around the substrate, Multiple second annular member pieces are arranged in a manner that alternates circumferentially with the multiple first annular member pieces obtained by dividing the first annular member. Each of the plurality of second annular component pieces includes: A movable part has a first surface facing radially inward, and is capable of moving to either a first height position opposite to an end of the substrate or a second height position lower than the first height position; and a stationary part is disposed outside the movable part at the first height position, and has a second surface facing radially inward. When the horizontal distance between the end of the substrate and the inner end of the first annular member is different, The movable portion of the second annular member piece is moved to either the first height position or the second height position so that either the first surface or the second surface is opposite to the end of the substrate, thereby making the horizontal distance between the end of the substrate and the inner end of the second annular member piece different.

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