Plasma processing apparatus

Abstract

The present application provides a kind of plasma processing device, can control the inclination at the edge of substrate while inhibiting the process variation of the central and intermediate region of substrate.The plasma processing device has: plasma processing container;Substrate support part, it is configured in plasma processing container, including electrostatic chuck;First ring, it is configured on electrostatic chuck in the manner of surrounding the substrate on electrostatic chuck, including inner annular portion, intermediate annular portion and outer annular portion, the upper surface of inner annular portion is higher than the upper surface of intermediate annular portion, the upper surface of outer annular portion is higher than the upper surface of inner annular portion;Second ring, it is configured on the upper surface of intermediate annular portion of first ring;And actuator, it is configured to move second ring along longitudinal direction to maintain the upper surface of second ring as first height, first height is greater than the height of the upper surface of inner annular portion of first ring and less than the height of the upper surface of outer annular portion of first ring.

Description

Technical Field

[0001] This disclosure relates to a plasma processing apparatus. Background Technology

[0002] Plasma processing apparatuses perform plasma processing, such as etching, on substrates like semiconductor wafers (hereinafter also referred to as wafers or substrates). During plasma processing, components within the chamber are consumed, affecting the results. For example, when a focusing ring located on the outer periphery of the wafer to homogenize the plasma is consumed and the height of its upper surface decreases, a height discrepancy occurs between the wafer and the plasma sheath on the focusing ring, affecting the uniformity of the plasma processing. Therefore, a lifting mechanism has been proposed to raise the focusing ring.

[0003] Existing technical documents

[0004] Patent documents

[0005] Patent Document 1: Japanese Patent Application Publication No. 2019-071369

[0006] Patent Document 2: U.S. Patent Application Publication No. 2017 / 0236741 Summary of the Invention

[0007] The problem the invention aims to solve

[0008] This disclosure provides a plasma processing apparatus capable of suppressing process variations in the central and intermediate regions of a substrate while suppressing tilting at the substrate edge.

[0009] Solution for solving the problem

[0010] A plasma processing apparatus according to one aspect of the present disclosure includes: a plasma processing container; a substrate support disposed within the plasma processing container, the substrate support including an electrostatic chuck; a first ring disposed on the electrostatic chuck to surround a substrate on the electrostatic chuck, the first ring including an inner annular portion, a middle annular portion, and an outer annular portion, the upper surface of the inner annular portion being higher than the upper surface of the middle annular portion, and the upper surface of the outer annular portion being higher than the upper surface of the inner annular portion; a second ring disposed on the upper surface of the middle annular portion of the first ring; and an actuator configured to move the second ring longitudinally to maintain the upper surface of the second ring at a first height, wherein the first height is higher than the height of the upper surface of the inner annular portion of the first ring and lower than the height of the upper surface of the outer annular portion of the first ring.

[0011] The effects of the invention

[0012] According to this disclosure, it is possible to suppress process variations in the central and intermediate regions of the substrate while controlling the tilt at the ends of the substrate. Attached Figure Description

[0013] Figure 1 This is a diagram illustrating an example of a plasma processing system according to a first embodiment of the present disclosure.

[0014] Figure 2 This is an enlarged view showing an example of a cross-section near the edge ring of the first embodiment.

[0015] Figure 3 This is an enlarged view showing an example of a cross-section near the edge ring in the state where the second ring is raised, according to the first embodiment.

[0016] Figure 4 This is a diagram showing an example of the equivalent circuit near the edge ring of the first embodiment.

[0017] Figure 5 This is a diagram showing an example of the tilt angle at the end of the substrate.

[0018] Figure 6 This is a diagram showing an example of the tilt angle at the end of the substrate.

[0019] Figure 7 This is an enlarged view showing an example of a cross-section near the edge ring of the second embodiment.

[0020] Figure 8 This is an enlarged view showing an example of a cross-section near the edge ring in the third embodiment.

[0021] Figure 9 This is a diagram illustrating an example of the experimental results of the third embodiment.

[0022] Figure 10 This is a diagram illustrating an example of the experimental results of the third embodiment.

[0023] Explanation of reference numerals in the attached figures

[0024] 1: Plasma processing system; 10: Plasma processing device; 11: Plasma processing chamber; 20: Substrate support; 21: Lower electrode; 22: Electrostatic chuck; 23, 23E, 23G: Edge rings; 23a, 23c, 23f: First ring; 23b: Second ring; 23d: Third ring; 24, 24a, 24b: Covering rings; 27: Through hole; 28: Drive pin; 29: Actuator; 100: Control unit; W: Substrate. Detailed Implementation

[0025] Hereinafter, embodiments of the disclosed plasma processing apparatus will be described in detail based on the accompanying drawings. Furthermore, the disclosed technology is not limited to the embodiments described below.

[0026] When the height of the focus ring is changed by raising it using a lifting mechanism, the impedance at the wafer's edge changes. Therefore, process variations occur, such as changes in the etching rate, in the center of the wafer and the intermediate region between the center and the edge. Furthermore, when the focus ring is raised more than 5 mm relative to the wafer for tilt control, the ratio of RF power at the wafer's edge changes or the flow of process gas is obstructed, again causing process variations. Therefore, it is desirable to control the tilt at the wafer (substrate) edge while suppressing process variations in the center and intermediate regions of the wafer.

[0027] (First Implementation)

[0028] [Structure of Plasma Processing System 1]

[0029] Figure 1 This is a diagram illustrating an example of a plasma processing system according to a first embodiment of the present disclosure. (See diagram for example.) Figure 1 As shown, in one embodiment, the plasma processing system 1 includes a plasma processing apparatus 10 and a control unit 100. The plasma processing apparatus 10 is an ICP (Inductively Coupled Plasma) plasma processing apparatus, including a plasma processing chamber 11, a gas supply unit 50, an RF (Radio Frequency) power supply unit 300, and an exhaust system 15. Additionally, the plasma processing apparatus 10 includes a substrate support 20, a gas injection unit 41, and an antenna 62. The substrate support 20 is disposed in the lower region of the plasma processing space 11s within the plasma processing chamber 11. The gas injection unit 41 is disposed above the substrate support 20 and mounted on the central opening of the dielectric window 61. The antenna 62 is disposed above or above the plasma processing chamber 11 (dielectric window 61).

[0030] The substrate support portion 20 is configured to support the substrate W in the plasma processing space 11s. The substrate support portion 20 is an example of a stage. In one embodiment, the substrate support portion 20 includes a lower electrode 21, an electrostatic chuck 22, and an edge ring 23. The electrostatic chuck 22 is disposed on the lower electrode 21 and configured to support the substrate W via its upper surface. The lower electrode 21 functions as a bias electrode. The edge ring 23 is disposed on the upper surface of the periphery of the lower electrode 21 in a manner that surrounds the substrate W. Additionally, although not shown in the figures, in one embodiment, the substrate support portion 20 may also include a temperature control module configured to adjust at least one of the electrostatic chuck 22 and the substrate W to a target temperature. The temperature control module may include a heater, a flow path, or a combination thereof. A temperature-regulating fluid such as a refrigerant or a heat transfer gas flows in the flow path.

[0031] The edge ring 23 has a first ring 23a and a second ring 23b. The first ring 23a has a placement portion, and the second ring 23b is disposed on the upper part of the placement portion. The thickness of the first ring 23a on the inner peripheral side of the placement portion is greater than that of the placement portion. That is, the first ring 23a is disposed on the electrostatic chuck 22 in a manner that surrounds the substrate W on the electrostatic chuck 22. In addition, the first ring 23a includes an inner annular portion on the inner peripheral side of the placement portion and an outer annular portion including the placement portion. The height of the upper surface of the inner annular portion is greater than the height of the upper surface of the outer annular portion.

[0032] The second ring 23b is configured such that its width is narrower than that of the first ring 23a, and its thickness is thinner than or the same as the thickness of the thinnest part of the first ring 23a, i.e., the placement portion. The width of the second ring 23b can, for example, be less than 15 mm. That is, the second ring 23b is disposed on the upper surface of the outer annular portion of the first ring 23a. Furthermore, the inner diameter of the second ring 23b is larger than the inner diameter of the first ring 23a, and the outer diameter of the second ring 23b is smaller than the outer diameter of the first ring 23a. In other words, the width of the second ring 23b is smaller than the width of the outer annular portion of the first ring 23a.

[0033] A cover ring 24 is disposed on the outer periphery of the edge ring 23. The cover ring 24 is mounted on the support portion 26 via an insulator 25. The cover ring 24 is disposed such that it covers a portion of the upper surface and the outer peripheral side of the first ring 23a and surrounds the second ring 23b. In addition, the upper surface of the cover ring 24 is higher than the upper surface of the inner annular portion of the first ring 23a. Furthermore, the first ring 23a and the second ring 23b are made of a conductive material, such as silicon (Si) or silicon carbide (SiC), while the cover ring 24 is made of an insulating material, such as quartz (SiO2).

[0034] Furthermore, the second ring 23b contacts the drive pin 28, which passes through a through hole 27 provided in the first ring 23a, the lower electrode 21, and the electrostatic chuck 22. The drive pin 28 can move vertically via an actuator 29, which serves as a drive mechanism, located below the lower electrode 21. The drive pin 28 is made of a conductive or insulating material. Examples of conductive materials include Al, Si, SiC, and Y₂O₃. Examples of insulating materials include quartz, alumina, and ceramics. The drive pin 28 and actuator 29 are provided at multiple locations, such as four locations, on the circumference of the second ring 23b to uniformly lift the second ring 23b. That is, the second ring 23b is configured such that the distance between the second ring 23b and the first ring 23a is adjustable.

[0035] In other words, the actuator 29 is configured to move the second ring 23b longitudinally to maintain the upper surface of the second ring 23b at a first height. Furthermore, in this case, the actuator 29 includes a drive pin 28. Additionally, the first height is greater than (higher) the height of the upper surface of the inner annular portion of the first ring 23a and less than (lower) the height of the upper surface of the cover ring 24.

[0036] The gas injection unit 41 is configured to supply one or more processing gases from the gas supply unit 50 to the plasma processing space 11s. In one embodiment, inlet ports 42a and 42b for introducing processing gases into the gas injection unit 41 are provided at the upper part of the gas injection unit 41. The inlet ports 42a and 42b are connected to pipes 56a and 56b, respectively. The lower part of the gas injection unit 41 protrudes downward from the lower surface of the dielectric window 61. An injection port 43a for injecting processing gases downward and an injection port 43b for injecting processing gases laterally are formed at the lower part of the gas injection unit 41.

[0037] The gas supply unit 50 may include one or more gas sources 51, one or more flow controllers 52, valves 53, piping 54, and a distributor (gas flow distribution unit) 55. In one embodiment, the gas supply unit 50 is configured to supply one or more types of process gases from their respective gas sources 51 via their respective flow controllers 52 and valves 53, piping 54, distributor 55, and piping 56a, 56b to the gas injection unit 41. Each flow controller 52 may, for example, include a mass flow controller (MFC) or a pressure-controlled flow controller.

[0038] The RF power supply unit 300 is configured to supply RF power, such as one or more RF signals, to the lower electrode 21 and antenna 62. This causes plasma to be generated from one or more processing gases supplied to the plasma processing space 11s. Therefore, the RF power supply unit 300 can function as at least part of a plasma generation unit configured to generate plasma from one or more processing gases in the plasma processing chamber. In one embodiment, the RF power supply unit 300 includes a first RF power supply unit 71 and a second RF power supply unit 30.

[0039] The first RF power supply unit 71 includes a first RF generation unit and a first matching circuit. In one embodiment, the first RF power supply unit 71 is configured to supply a first RF signal from the first RF generation unit to the antenna 62 via the first matching circuit. In one embodiment, the first RF signal is a source RF signal having a frequency of 100 MHz or less.

[0040] The second RF power supply unit 30 includes a second RF generation unit and a second matching circuit. In one embodiment, the second RF power supply unit 30 is configured to supply a second RF signal from the second RF generation unit to the lower electrode 21 via the second matching circuit. In one embodiment, the second RF signal is a bias RF signal having a frequency of 27 MHz or less.

[0041] Antenna 62 has an outer coil 621 and an inner coil 622 arranged coaxially with the gas jet section 41. The inner coil 622 is arranged around the gas jet section 41 in a manner surrounding it. The outer coil 621 is arranged around the inner coil 622 in a manner surrounding it. The outer coil 621 functions as a primary coil connected to the first RF power supply section 71. In one embodiment, the outer coil 621 is a planar coil formed in a generally circular spiral shape. The inner coil 622 functions as a secondary coil inductively coupled to the primary coil. That is, the inner coil 622 is not connected to the first RF power supply section 71. In one embodiment, the inner coil 622 is a planar coil formed in a generally circular loop shape. In one embodiment, the inner coil 622 is connected to a variable capacitor, and the direction and magnitude of the current flowing in the inner coil 622 are controlled by controlling the capacitance of the variable capacitor. The outer coil 621 and the inner coil 622 can be configured at the same height or at different heights. In one embodiment, the inner coil 622 is configured at a lower position than the outer coil 621.

[0042] The exhaust system 15 can be connected, for example, to an exhaust port 13 located at the bottom of the plasma processing chamber 11. The exhaust system 15 may include a pressure valve and a vacuum pump. The vacuum pump may include a turbomolecular pump, a roughing pump, or a combination thereof.

[0043] In one embodiment, the control unit 100 processes computer-executable commands that cause the plasma processing apparatus 10 to perform the various processes described herein. The control unit 100 can be configured to control various elements of the plasma processing apparatus 10 to perform the various processes described herein. In one embodiment, part or all of the control unit 100 may be included in the plasma processing apparatus 10. The control unit 100 may, for example, include a computer 101. The computer 101 may, for example, include a processing unit (CPU) 102, a storage unit 103, and a communication interface 104. The processing unit 102 can be configured to perform various control actions based on programs stored in the storage unit 103. The storage unit 103 may include RAM (Random Access Memory), ROM (Read Only Memory), HDD (Hard Disk Drive), SSD (Solid State Drive), or combinations thereof. The communication interface 104 can communicate with the plasma processing apparatus 10 via a communication line such as a LAN (Local Area Network).

[0044] [Impedance of edge ring 23]

[0045] Next, use Figures 2 to 4 To illustrate the impedance of edge ring 23. Figure 2 This is an enlarged view showing an example of a cross-section near the edge ring of the first embodiment. Figure 3 This is an enlarged view showing an example of a cross-section near the edge ring in the state where the second ring is raised in the first embodiment. Furthermore, in Figure 2 and Figure 3 In the original text, the through hole 27 and the drive pin 28 are omitted.

[0046] Figure 2 This indicates that the second ring 23b of the edge ring 23 has not been consumed. The RF power from the plasma generated in the plasma processing space 11s flows through path 80 from the low-impedance cover ring 24 side, via the outer annular portion of the first ring 23a and the electrostatic chuck 22, to the lower electrode 21 after reaching the surfaces of the second ring 23b and the cover ring 24. Furthermore, even when… Figure 2 In this state, there is also a tiny air gap between the first ring 23a and the second ring 23b.

[0047] Next, as Figure 3 As shown, when the second ring 23b is consumed and has risen, the air gap between the outer annular portion of the first ring 23a and the second ring 23b widens as shown by air gap 35. In this case, RF power flows through path 80 from the low-impedance cover ring 24 side, via the outer annular portion of the first ring 23a and the electrostatic chuck 22, to the lower electrode 21. Furthermore, since air gap 35 is less than 5 mm, the process variations in the central and intermediate regions of the substrate W are minimal.

[0048] Figure 4 This diagram illustrates an example of the equivalent circuit near the edge ring in the first embodiment. Figure 4 In the middle, use Z A1 The impedance of the second ring 23b is represented by Z. A2 The impedance of the air gap (small air gap and air gap 35) is represented by Z. A Z represents A1 With Z A2 The combined impedance. Additionally, using Z... B The impedance of the cover ring 24 is represented by Z. C This represents the impedance of the first ring 23a. Additionally, the combined impedance Z near the edge ring 23 is... total It can be represented by the following formula (1).

[0049]

Number 1

[0050]

[0051] As shown in equation (1), Z total For Z A Z B and Z C The combined impedance. Due to the presence of an air gap, Z A It gets higher. On the other hand, Z... B Set as impedance ratio Z A The impedance is low, that is, Z B Set as Z A The bypass impedance of the bypass circuit functions. For example, the thickness of the cover ring 24 is adjusted to reduce the impedance relative to the RF power. In equation (1), when the air gap widens, Z A2 Increase thus Z A It also increased, but Z B In a dominant position, Z total ≈Z B +Z C Furthermore, in Z B Compared to Z AThe same applies when the value is very small. Therefore, even if the air gap changes, the change in the combined impedance near the edge ring 23 is small and remains constant. That is, in this embodiment, even if the second ring 23b is raised, process variations in the central and intermediate regions of the substrate W can be suppressed.

[0052] [Tilt Angle]

[0053] Next, use Figure 5 and Figure 6 To explain the tilt angle. Figure 5 and Figure 6 This is a diagram showing an example of the tilt angle at the end of the substrate. Figure 5 This indicates a case where etching was performed with the plasma sheath on the second ring 23b being consumed and tilted in a manner where the plasma sheath on the second ring 23b is lower than the plasma sheath on the substrate W. In this case, the hole 90 formed at the end of the substrate W has a negative tilt angle 91. The tilt angle 91 is also called inward tilt.

[0054] Figure 6 This indicates that etching was performed with the second ring 23b raised and the plasma sheath on the second ring 23b tilted relative to the plasma sheath on the substrate W. In this case, the hole 92 formed at the end of the substrate W has a positive tilt angle 93. The tilt angle 93 is also called outward tilt. That is, in this embodiment, by raising the second ring 23b to adjust the distance between the first ring 23a and the second ring 23b, the tilt at the end of the substrate W can be controlled.

[0055] (Second Implementation)

[0056] In the first embodiment described above, the thickness of the first ring 23a in the RF power path 80 is set to be the same as the thickness of the configuration portion of the second ring 23b, that is, the thickness of the thinnest part of the first ring 23a, but it may also be thicker than the thickness of the configuration portion. This situation will be described below as a second embodiment.

[0057] Figure 7 This is an enlarged view showing an example of a cross-section near the edge ring in the second embodiment. Compared to the edge ring 23 in the first embodiment, Figure 7 The edge ring 23E shown has a first ring 23c and a third ring 23d instead of the first ring 23a. Furthermore, in the substrate support portion 20 of the second embodiment, a covering ring 24a is provided instead of the covering ring 24 of the first embodiment. Additionally, in... Figure 7 The through hole 27 and the drive pin 28 are omitted.

[0058] The first ring 23c is narrower in the radial direction than the first ring 23a, and the position of the outer peripheral end of the first ring 23c is approximately the same as the position of the outer peripheral end of the second ring 23b. That is, the first ring 23c is disposed on the electrostatic chuck 22 in a manner that surrounds the substrate W on the electrostatic chuck 22. Furthermore, the first ring 23c includes an inner annular portion closer to the inner periphery than the placement portion, and an outer annular portion including the placement portion; the upper surface of the inner annular portion is higher than the upper surface of the outer annular portion. The second ring 23b is disposed on the upper surface of the outer annular portion of the first ring 23c. Furthermore, the width of the second ring 23b is the same as the width of the outer annular portion of the first ring 23c.

[0059] The third ring 23d is positioned further outwards, surrounding the first ring 23c and the second ring 23b. In other words, the third ring 23d is arranged to enclose the first ring 23c and the second ring 23b. The third ring 23d is a component obtained by separating the portion of the first ring 23a covered by the covering ring 24, and this portion is thicker than the portion of the first ring 23a. That is, a gap is formed between the first ring 23c and the third ring 23d. Furthermore, at least a portion of the third ring 23d is disposed on the electrostatic chuck 22.

[0060] Furthermore, compared to the cover ring 24, the thickness of the portion of the cover ring 24a covering the third ring 23d is reduced by an amount corresponding to the thickness of the third ring 23d. That is, the cover ring 24a is configured to cover both the upper surface and the outer peripheral side of the third ring 23d. Additionally, the upper surface of the cover ring 24a is higher than the upper surface of the inner annular portion of the first ring 23c.

[0061] Similar to the first ring 23a, the first ring 23c is made of a conductive material, such as silicon (Si) or silicon carbide (SiC). Furthermore, the third ring 23d can be made of a conductive material, such as silicon (Si) or silicon carbide (SiC), or a conductive ceramic with higher conductivity can be used. That is, the third ring 23d can be made of a material with a higher conductivity than the first ring 23c and the second ring 23b. Similarly to the cover ring 24, the cover ring 24a is made of an insulating material, such as quartz (SiO2).

[0062] Additionally, similar to the first embodiment, the actuator 29 is configured to move the second ring 23b longitudinally to maintain the upper surface of the second ring 23b at a first height. Furthermore, in this case, the actuator 29 includes a drive pin 28. Additionally, the first height is greater than (higher) the height of the upper surface of the inner annular portion of the first ring 23c and less than (lower) the height of the upper surface of the covering ring 24a.

[0063] exist Figure 7In the plasma processing space 11s, the RF power from the plasma generated in the plasma processing space 11s flows through path 81 from the lower electrode 21 via the third ring 23d and the electrostatic chuck 22 after reaching the surfaces of the second ring 23b and the covering ring 24a. That is, the thickness difference between the third ring 23d and the first ring 23a, along with the combined impedance of the covering ring 24a, corresponds to... Figure 4 Z shown B Furthermore, even with the second ring 23b raised, RF power flows through path 81 from the low-impedance cover ring 24a side via the third ring 23d and the electrostatic chuck 22 to the lower electrode 21. Thus, even when the edge ring 23E is used, similar to the first embodiment, it is possible to suppress process variations in the central and intermediate regions of the substrate W while controlling the tilt at the ends of the substrate W.

[0064] (Third Implementation)

[0065] In the second embodiment described above, the third ring 23d in the RF power path 81 is set to be separate from the first ring 23c, but they can also be integrated. This situation will be described below as the third embodiment.

[0066] Figure 8 This is an enlarged view showing an example of a cross-section near the edge ring in the third embodiment. Compared to the edge ring 23E in the second embodiment, Figure 8 The edge ring 23G shown has a first ring 23f instead of the first ring 23c and the third ring 23d. Furthermore, in the substrate support portion 20 of the third embodiment, a covering ring 24b is provided instead of the covering ring 24a of the second embodiment. Additionally, in... Figure 8 The through hole 27 and the drive pin 28 are omitted.

[0067] The first ring 23f is a component that integrates the first ring 23c and the third ring 23d, and has a portion on the outer periphery of the first ring 23f that is thicker than the placement portion. The thickness of the outer periphery of the placement portion of the first ring 23f is greater than the thickness of the inner periphery of the placement portion. That is, the first ring 23f is disposed on the electrostatic chuck 22 in a manner that surrounds the substrate W on the electrostatic chuck 22. In addition, the first ring 23f includes an inner annular portion on the inner periphery of the placement portion, a middle annular portion serving as the placement portion, and an outer annular portion on the outer periphery of the placement portion. Here, in the first ring 23f, the upper surface of the inner annular portion is higher than the upper surface of the middle annular portion, and the upper surface of the outer annular portion is higher than the upper surface of the inner annular portion. The second ring 23b is disposed on the upper surface of the middle annular portion of the first ring 23f. The width of the second ring 23b is the same as or smaller than the width of the middle annular portion of the first ring 23f.

[0068] The cover ring 24b is configured to surround the first ring 23f. Compared to the cover ring 24a, the cover ring 24b removes the portion covering the outer annular portion of the first ring 23f. Like the first ring 23c, the first ring 23f is made of a conductive material, such as silicon (Si) or silicon carbide (SiC). Like the cover ring 24, the cover ring 24b is made of an insulating material, such as quartz (SiO2).

[0069] Similarly to the first embodiment, the actuator 29 is configured to move the second ring 23b longitudinally to maintain the upper surface of the second ring 23b at a first height. Furthermore, in this case, the actuator 29 includes a drive pin 28. Additionally, the first height is greater than (higher) the height of the upper surface of the inner annular portion of the first ring 23f and less than (lower) the height of the upper surface of the outer annular portion of the first ring 23f.

[0070] exist Figure 8 In the plasma processing space 11s, the RF power from the plasma, after reaching the surfaces of the second ring 23b, the first ring 23f, and the covering ring 24b, flows through path 82 from the outer annular portion of the first ring 23f (with lower impedance) to the lower electrode 21 via the electrostatic chuck 22. That is, the impedance of the outer annular portion of the first ring 23f and the portion with the thickness difference from the first ring 23a are the same. Figure 4 Z shown B Correspondingly. Furthermore, even when the second ring 23b is raised, RF power flows through path 82 from the outer annular portion of the first ring 23f (with low impedance) via the electrostatic chuck 22 to the lower electrode 21. In this way, even when using the edge ring 23G, it is possible, as in the first and second embodiments, to suppress process variations in the central and middle regions of the substrate W while controlling the tilt at the ends of the substrate W.

[0071] [Experimental Results]

[0072] Next, use Figure 9 and Figure 10 The experimental results of the third implementation method will be explained. Figure 9 and Figure 10 This is a diagram illustrating an example of the experimental results of the third embodiment. Figure 9 and Figure 10 In this design, the radial width of the first ring 23f is set to 14 mm, the thickness of the arrangement part (middle annular portion) is set to 2.2 mm, and the thickness of the outer annular portion of the first ring 23f is set to 4.4 mm. Additionally, the radial width of the second ring 23b is set to 7 mm, and its thickness is set to 1.8 mm (1.8t).

[0073] In addition, Figure 9 and Figure 10In the comparison, the case where the second ring 23b does not rise (represented as 1.8t in the figure), the case where the second ring 23b rises by 1 mm without consumption (represented as 1.8t + 1mm up in the figure), and the case where the second ring 23b rises by 2 mm without consumption (represented as 1.8t + 2mm up in the figure) are compared. Furthermore, a 300mm wafer was used for the substrate W.

[0074] Figure 9 This represents the radial distribution of the etching rate when substrate W has been etched. For example... Figure 9 As shown, compared to the case where the second ring 23b is not raised, the etching rate changes significantly at the ends of the substrate W when the second ring 23b is raised by 1 mm and 2 mm. On the other hand, the etching rate change in the central and middle regions (diameter 280 mm) of the substrate W is 0.5%. Therefore, it can be concluded that even when the second ring 23b is raised, process variations in the central and middle regions of the substrate W can be suppressed. Furthermore, regarding the ends of the substrate W, when the second ring 23b is raised while it is already worn out, the etching rate is close to the etching rate in the case where it is not worn out.

[0075] Figure 10 This indicates the tilt angle at the end of substrate W. For example... Figure 10 As shown, the tilt angle is negative when the second ring 23b is not raised, and positive when the second ring 23b is raised by 1 mm and 2 mm. Furthermore, the tilt angle is larger in the positive direction when the second ring 23b is raised by 2 mm compared to the case where it is raised by 1 mm. In this way, the tilt at the end of the substrate W can be controlled according to the amount by which the second ring 23b is raised.

[0076] According to the third embodiment, the plasma processing apparatus 10 includes: a plasma processing container (plasma processing chamber 11); a substrate support 20 disposed within the plasma processing container, the substrate support 20 including an electrostatic chuck; a first ring 23f disposed on the electrostatic chuck 22 surrounding the substrate W on the electrostatic chuck 22, the first ring 23f including an inner annular portion, a middle annular portion, and an outer annular portion, the upper surface of the inner annular portion being higher than the upper surface of the middle annular portion, and the upper surface of the outer annular portion being higher than the upper surface of the inner annular portion; a second ring 23b disposed on the upper surface of the middle annular portion of the first ring 23f; and an actuator 29 configured to move the second ring 23b longitudinally to maintain the upper surface of the second ring 23b at a first height, the first height being higher than the height of the upper surface of the inner annular portion of the first ring 23f and lower than the height of the upper surface of the outer annular portion of the first ring 23f. As a result, it is possible to suppress process variations in the central and intermediate regions of the substrate W while controlling the tilt at the ends of the substrate W. Additionally, it is possible to reduce variations in the combined impedance near the edge ring 23G.

[0077] Furthermore, according to the third embodiment, the width of the second ring 23b can be the same as or smaller than the width of the middle annular portion of the first ring 23f. As a result, process variations in the central and intermediate regions of the substrate W can be suppressed while controlling the tilt at the ends of the substrate W. Additionally, variations in the combined impedance near the edge ring 23G can be reduced.

[0078] Furthermore, according to the third embodiment, the first ring 23f and the second ring 23b are made of silicon or silicon carbide. As a result, the variation in the synthesized impedance near the edge ring 23G can be reduced.

[0079] Furthermore, according to the third embodiment, a covering ring 24b is provided, which is configured to surround the first ring 23f, and the covering ring 24b is made of an insulating material. As a result, the variation in the combined impedance near the edge ring 23G can be reduced.

[0080] Furthermore, according to the second embodiment, the plasma processing apparatus 10 includes: a plasma processing container (plasma processing chamber 11); a substrate support 20 disposed within the plasma processing container, including an electrostatic chuck 22; a first ring 23c made of a conductive material, disposed on the electrostatic chuck 22 to surround the substrate W on the electrostatic chuck 22, the first ring 23c including an inner annular portion and an outer annular portion, the upper surface of the inner annular portion being higher than the upper surface of the outer annular portion; and a second ring 23b disposed on the upper surface of the outer annular portion of the first ring 23c, the second ring 23b being made of a conductive material. The system comprises: a third ring 23d, configured to surround the first ring 23c and the second ring 23b, the third ring 23d being made of conductive material; a cover ring 24a, made of insulating material, configured to cover the upper surface and outer peripheral side of the third ring 23d, the upper surface of the cover ring 24a being higher than the upper surface of the inner annular portion of the first ring 23c; and an actuator 29 configured to move the second ring 23b longitudinally to maintain the upper surface of the second ring 23b at a first height, the first height being higher than the height of the upper surface of the inner annular portion of the first ring 23c and lower than the height of the upper surface of the cover ring 24a. As a result, process variations in the central and intermediate regions of the substrate W can be suppressed while controlling the tilt at the ends of the substrate W. Furthermore, variations in the combined impedance near the edge ring 23E can be reduced.

[0081] Furthermore, according to the second embodiment, the third ring 23d is made of a material having a higher conductivity than the first ring 23c and the second ring 23b. As a result, the variation in the combined impedance near the edge ring 23E can be further reduced.

[0082] Furthermore, according to the second embodiment, a gap is formed between the first ring 23c and the third ring 23d. As a result, RF power can be further allowed to flow from the third ring 23d side to the lower electrode 21.

[0083] Furthermore, according to the second embodiment, at least a portion of the third ring 23d is disposed on the electrostatic chuck 22. As a result, the variation in the combined impedance near the edge ring 23E can be further reduced.

[0084] Furthermore, according to the second embodiment, the width of the second ring 23b is the same as the width of the outer annular portion of the first ring 23c. As a result, it is possible to suppress process variations in the central and intermediate regions of the substrate W while controlling the tilt at the ends of the substrate W.

[0085] Furthermore, according to the second embodiment, the first ring 23c, the second ring 23b, and the third ring 23d are made of silicon or silicon carbide. As a result, the variation in the combined impedance near the edge ring 23E can be reduced.

[0086] Furthermore, according to the first embodiment, the plasma processing apparatus 10 includes: a plasma processing container (plasma processing chamber 11); a substrate support 20 disposed within the plasma processing container, the substrate support 20 including an electrostatic chuck 22; a first ring 23a made of conductive material, disposed on the electrostatic chuck 22 to surround the substrate W on the electrostatic chuck 22, the first ring 23a including an inner annular portion and an outer annular portion, the height of the upper surface of the inner annular portion being higher than the height of the upper surface of the outer annular portion; and a second ring 23b made of conductive material, disposed on the outer annular portion of the first ring 23a. The upper surface of the substrate W has a second ring 23b with an inner diameter larger than that of the first ring 23a, and an outer diameter smaller than that of the first ring 23a. A cover ring 24, made of insulating material, is configured to cover a portion of the upper surface and outer peripheral side of the first ring 23a and surround the second ring 23b. The upper surface of the cover ring 24 is higher than the upper surface of the inner annular portion of the first ring 23a. An actuator 29 is configured to move the second ring 23b longitudinally to maintain the upper surface of the second ring 23b at a first height, which is higher than the height of the upper surface of the inner annular portion of the first ring 23a and lower than the height of the upper surface of the cover ring 24. As a result, process variations in the central and intermediate regions of the substrate W can be suppressed while controlling the tilt at the ends of the substrate W.

[0087] Furthermore, according to the first embodiment, the width of the second ring 23b is smaller than the width of the outer annular portion of the first ring 23a. As a result, the variation in the combined impedance near the edge ring 23 can be reduced.

[0088] Furthermore, according to the first embodiment, the first ring 23a and the second ring 23b are made of silicon or silicon carbide. As a result, the variation in the synthesis impedance near the edge ring 23 can be reduced.

[0089] The above descriptions illustrate various exemplary embodiments, but the embodiments are not limited to these exemplary embodiments. Various additions, omissions, substitutions, and modifications can be made. Furthermore, elements from different embodiments can be combined to form other embodiments.

[0090] Furthermore, in the embodiments described above, a plasma processing apparatus 10 that uses inductively coupled plasma as a plasma source to perform etching and other processes on the substrate W has been described as an example, but the disclosed technology is not limited to this. Any apparatus that uses plasma to process the substrate W is acceptable, and the plasma source is not limited to inductively coupled plasma. For example, any plasma source such as capacitively coupled plasma, microwave plasma, or magnetron plasma can be used.

Claims

1. A plasma processing device, comprising: Plasma processing container; A substrate support portion disposed within the plasma processing container, the substrate support portion including an electrostatic chuck; A first ring is disposed on the electrostatic chuck in such a way as to surround the substrate on the electrostatic chuck. The first ring includes an inner ring-shaped portion, a middle ring-shaped portion, and an outer ring-shaped portion. The upper surface of the inner ring-shaped portion is higher than the upper surface of the middle ring-shaped portion, and the upper surface of the outer ring-shaped portion is higher than the upper surface of the inner ring-shaped portion. A second ring is disposed on the upper surface of the middle annular portion of the first ring, and its thickness is the same as or thinner than the thickness of the middle annular portion, wherein the upper surface of the second ring is located at a first height, which is higher than the height of the upper surface of the inner annular portion of the first ring and lower than the height of the upper surface of the outer annular portion of the first ring. as well as An actuator configured to move the second ring longitudinally to maintain the upper surface of the second ring at the first height.

2. The plasma processing apparatus according to claim 1, characterized in that, The width of the second ring is the same as or smaller than the width of the middle annular portion of the first ring.

3. The plasma processing apparatus according to claim 1 or 2, characterized in that, The first ring and the second ring are made of silicon or silicon carbide.

4. The plasma processing apparatus according to claim 3, characterized in that, It also has a cover ring, which is configured to surround the first ring, and the cover ring is made of an insulating material.

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