Substrate processing apparatus, stage, and temperature control method

Abstract

A substrate processing apparatus, a stage, and a temperature control method capable of controlling deformation of a stage are provided. The substrate processing apparatus has a stage for placing a substrate, the stage having a first plate, a first temperature adjustment mechanism that controls the temperature of the first plate, a second plate disposed at a lower portion of the first plate, a second temperature adjustment mechanism that controls the temperature of the second plate, and a fastening member that fastens the first plate and the second plate together.

Description

Technical Field

[0001] This disclosure relates to a substrate processing apparatus, a mounting stage, and a temperature control method. Background Technology

[0002] It is known that substrates can warp or deform due to manufacturing processes (see, for example, Patent Document 1). Furthermore, it is known that mounting stages can warp or deform due to thermal stress (see, for example, Patent Document 2).

[0003] Existing technical documents

[0004] Patent documents

[0005] Patent Document 1: Japanese Patent Application Publication No. 2005-72286

[0006] Patent Document 2: Japanese Patent Application Publication No. 2000-21962 Summary of the Invention

[0007] The problem the invention aims to solve

[0008] This disclosure provides a technique for controlling the deformation of a mounting stage.

[0009] Solution for solving the problem

[0010] According to one aspect of this disclosure, a substrate processing apparatus is provided, the substrate processing apparatus having a mounting stage for placing a substrate, wherein the mounting stage has: a first plate; a first temperature regulating mechanism for controlling the temperature of the first plate; a second plate disposed below the first plate; a second temperature regulating mechanism for controlling the temperature of the second plate; and a fastening member for fastening the first plate and the second plate together.

[0011] The effects of the invention

[0012] Based on one aspect, it is possible to control the deformation of the mounting platform. Attached Figure Description

[0013] Figure 1 This is a cross-sectional schematic diagram illustrating an example of the substrate processing apparatus involved in the embodiment.

[0014] Figure 2 This diagram illustrates an example of temperature control of the mounting platform according to the embodiment.

[0015] Figure 3 This diagram illustrates an example of temperature control of the mounting platform according to the embodiment.

[0016] Figure 4 This is a diagram illustrating other examples of temperature control of the stage involved in the implementation method.

[0017] Figure 5 This is a diagram illustrating other examples of temperature control of the stage involved in the implementation method.

[0018] Figure 6 This is a diagram illustrating an example of a temperature control method involved in the implementation method.

[0019] Figure 7 This is a diagram illustrating an example of the configuration of multiple sensors involved in an implementation method.

[0020] Explanation of reference numerals in the attached figures

[0021] 1: Substrate processing apparatus; 10: Chamber; 14: Stage; 16: Second plate; 16f: Second flow path; 18: First plate; 18f: First flow path; 20: Electrostatic chuck; 20a: Substrate mounting surface; 21a: First cooling device; 21b: Second cooling device; 30: Upper electrode; 34: Top plate; 36: Support; 38: Gas supply pipe; 40: Gas source group; 42: Valve group; 44: Flow controller group; 46: Shielding component; 48: Baffle; 70: Power supply; 80: Control unit; 81, 82: Strain gauge; 83: Laser interferometer. Detailed Implementation

[0022] The manner in which this disclosure is carried out will now be described with reference to the accompanying drawings. In the drawings, the same structural parts are labeled with the same reference numerals, and sometimes repeated descriptions are omitted.

[0023] [Substrate Processing Apparatus]

[0024] First, refer to Figure 1 This will illustrate an example of the substrate processing apparatus involved in the embodiment. Figure 1 This diagram illustrates an example of a substrate processing apparatus according to the embodiment. The substrate processing apparatus 1 is a capacitively coupled type apparatus.

[0025] The substrate processing apparatus 1 has a chamber 10. An internal space 10s is provided within the chamber 10. The chamber 10 includes a chamber body 12. The chamber body 12 has a generally cylindrical shape. The internal space 10s is provided inside the chamber body 12. The chamber body 12 is formed, for example, of aluminum. A corrosion-resistant film is provided on the inner wall surface of the chamber body 12. The corrosion-resistant film can be an oxide film formed from ceramics such as alumina or yttrium oxide and subjected to anodizing treatment.

[0026] A passage 12p is formed on the side wall of the chamber body 12. When the substrate W is transported between the internal space 10s and the outside of the chamber 10, the substrate W passes through the passage 12p. The passage 12p can be opened and closed by a gate valve 12g. The gate valve 12g is provided along the side wall of the chamber body 12.

[0027] A support portion 13 is provided on the bottom of the chamber body 12. The support portion 13 is formed of an insulating material. The support portion 13 has a generally cylindrical shape. The support portion 13 extends upward from the bottom of the chamber body 12 within the internal space 10s. An edge ring 25 (also called a focusing ring) surrounding the substrate is provided on the support portion 13. The edge ring 25 has a generally cylindrical shape and may be formed of silicon or the like.

[0028] The substrate processing apparatus 1 also includes a mounting stage 14. The mounting stage 14 is supported by a support portion 13. The mounting stage 14 is disposed in the internal space 10s. The mounting stage 14 is configured to support the substrate W within the chamber 10, i.e., the internal space 10s.

[0029] The mounting stage 14 has a first plate 18 and an electrostatic chuck 20 according to an exemplary embodiment. The mounting stage 14 may also have a second plate 16. The second plate 16 is formed, for example, of a conductor such as aluminum or titanium, and has a generally disc shape. The first plate 18 is disposed on top of the second plate 16. The first plate 18 is formed, for example, of a conductor such as aluminum or titanium, and has a generally disc shape. The first plate 18 and the second plate 16 may be made of ceramic. Preferably, the first plate 18 and the second plate 16 are made of the same metal (conductive member). By using conductive members to construct the first plate 18 and the second plate 16, the friction between the first plate 18 and the second plate 16 is increased compared to the case where the first plate 18 and the second plate 16 are constructed of ceramic. Therefore, the deformation of the mounting stage 14 (substrate mounting surface 20a) described later can be well controlled.

[0030] The first plate 18 and the second plate 16 are fastened together at the outer periphery of each plate by screws 19. The screws 19 are an example of fastening members that fasten the first plate 18 and the second plate 16 together by means of being arranged across the contact surfaces of the first plate 18 and the second plate 16.

[0031] An electrostatic chuck 20 is disposed on the first plate 18. The electrostatic chuck 20 is fixed to the first plate 18 by an adhesive layer disposed between the electrostatic chuck 20 and the first plate 18. The electrodes of the electrostatic chuck 20 are connected to a DC power supply 20p via a switch 20s. When a DC voltage is applied to the electrodes from the DC power supply 20p, the substrate W is held on the electrostatic chuck 20 by electrostatic attraction. The electrostatic chuck 20 supports the substrate W. The outer peripheral surfaces of the first plate 18 and the second plate 16 are surrounded by the support portion 13. Alternatively, the electrostatic chuck 20 may not be disposed on the mounting stage 14.

[0032] A first flow path 18f is provided inside the first plate 18. A heat transfer medium (e.g., refrigerant) is supplied to the first flow path 18f from a first cooling device 21a located outside the chamber 10 via a pipe 22a. The first cooling device 21a can adjust the temperature of the heat transfer medium to any temperature. The heat transfer medium supplied to the first flow path 18f returns to the first cooling device 21a via a pipe 22b.

[0033] A second flow path 16f is provided inside the second plate 16. A heat transfer medium (e.g., refrigerant) is supplied to the second flow path 16f from a second cooling device 21b located outside the chamber 10 via piping 23a. The second cooling device 21b can adjust the temperature of the heat transfer medium to any temperature. The heat transfer medium supplied to the second flow path 16f returns to the second cooling device 21b via piping 23b. The first flow path 18f and the second flow path 16f are different flow paths, allowing for separate temperature control of the heat transfer medium passing through the first flow path 18f and the heat transfer medium passing through the second flow path 16f.

[0034] The first flow path 18f and the first cooling device 21a are examples of a first temperature regulating mechanism provided on the first plate 18. The first temperature regulating mechanism may be at least one of a heater and a Peltier element. The second flow path 16f and the second cooling device 21b are examples of a second temperature regulating mechanism provided on the second plate 16. The second temperature regulating mechanism may be at least one of a heater and a Peltier element.

[0035] A gas supply line 24 is provided in the substrate processing apparatus 1. The gas supply line 24 supplies heat transfer gas (e.g., He gas) from the heat transfer gas supply mechanism to the space between the upper surface of the electrostatic chuck 20 and the lower surface of the substrate W.

[0036] The substrate processing apparatus 1 also includes an upper electrode 30. The upper electrode 30 is disposed above the stage 14. The upper electrode 30 is supported on the upper part of the chamber body 12 via a member 32. The member 32 is formed of an insulating material. The upper opening of the chamber body 12 is closed by the upper electrode 30.

[0037] The upper electrode 30 may include a top plate 34 and a support 36. The lower surface of the top plate 34 is the lower surface on the side adjacent to the internal space 10s, dividing the internal space 10s. The top plate 34 may be formed of a low-resistance conductor or semiconductor with low Joule heating. A plurality of gas ejection holes 34a are formed in the top plate 34. The plurality of gas ejection holes 34a penetrate the top plate 34 along the thickness direction of the top plate 34.

[0038] The support body 36 supports the top plate 34 in a removable manner. The support body 36 is made of a conductive material such as aluminum. A gas diffusion chamber 36a is provided inside the support body 36. Multiple gas holes 36b are formed in the support body 36. The multiple gas holes 36b extend downward from the gas diffusion chamber 36a. The multiple gas holes 36b are respectively connected to multiple gas ejection holes 34a. A gas inlet 36c is formed in the support body 36. The gas inlet 36c is connected to the gas diffusion chamber 36a. The gas inlet 36c is connected to the gas supply pipe 38.

[0039] Gas supply pipe 38 is connected to a gas supply unit including gas source group 40, flow controller group 44, and valve group 42. Gas source group 40 is connected to gas supply pipe 38 via flow controller group 44 and valve group 42. Gas source group 40 includes multiple gas sources. Valve group 42 includes multiple on / off valves. Flow controller group 44 includes multiple flow controllers. The multiple flow controllers of flow controller group 44 are either mass flow controllers or pressure-controlled flow controllers. The multiple gas sources of gas source group 40 are connected to gas supply pipe 38 via corresponding flow controllers of flow controller group 44 and corresponding on / off valves of valve group 42. Power supply 70 is connected to upper electrode 30. Power supply 70 applies a voltage to upper electrode 30 to attract positive ions present in the internal space within 10 seconds to top plate 34.

[0040] In the substrate processing apparatus 1, a shielding member 46 is detachably provided along the inner wall surface of the chamber body 12. The shielding member 46 is also provided on the outer periphery of the support portion 13. The shielding member 46 is used to prevent reaction products such as etching byproducts from adhering to the chamber body 12. The shielding member 46 is constructed, for example, by forming a corrosion-resistant film on the upper surface of a component made of aluminum. The corrosion-resistant film can be an oxide film such as aluminum oxide or yttrium oxide.

[0041] A baffle 48 is provided between the support portion 13 and the side wall of the chamber body 12. The baffle 48 is constructed, for example, by forming a corrosion-resistant film on the upper surface of a component made of aluminum. The corrosion-resistant film can be an oxide film such as aluminum oxide or yttrium oxide. A plurality of through holes are formed in the baffle 48. An exhaust port 12e is provided below the baffle 48 and at the bottom of the chamber body 12. The exhaust port 12e is connected to an exhaust device 50 via an exhaust pipe 52. The exhaust device 50 includes a pressure regulating valve and a vacuum pump such as a turbomolecular pump.

[0042] The substrate processing apparatus 1 includes a first high-frequency power supply 62 that applies high-frequency (HF) power for generating plasma. The first high-frequency power supply 62 is configured to generate HF power to generate plasma from the gas within the chamber 10. The frequency of the HF power supply is, for example, in the range of 27 MHz to 100 MHz.

[0043] The first high-frequency power supply 62 is electrically connected to the first board 18 via a matching adapter 66. The matching adapter 66 has a matching circuit. The matching circuit of the matching adapter 66 is configured to match the impedance of the load side (the stage 14 side) of the first high-frequency power supply 62 with the output impedance of the first high-frequency power supply 62. In other embodiments, the first high-frequency power supply 62 may also be electrically connected to the upper electrode 30 via the matching adapter 66.

[0044] The substrate processing apparatus 1 may also include a second high-frequency power supply 64 that applies power to a high-frequency LF for attracting ions. The second high-frequency power supply 64 is configured to generate power for the high-frequency LF. The high-frequency LF has a frequency primarily suitable for attracting ions to the substrate W, for example, a frequency in the range of 400 kHz to 13.56 MHz. Alternatively, the high-frequency LF may also be a pulsed voltage with a rectangular waveform.

[0045] The second high-frequency power supply 64 is electrically connected to the first board 18 via a matching unit 68. The matching unit 68 has a matching circuit. The matching circuit of the matching unit 68 is configured to match the impedance of the load side (the mounting platform 14 side) of the second high-frequency power supply 64 with the output impedance of the second high-frequency power supply 64.

[0046] The substrate processing apparatus 1 may also include a control unit 80. The control unit 80 may be a computer equipped with a processor, a memory (such as a storage unit), an input device, a display device, and signal input / output interfaces. The control unit 80 controls each part of the substrate processing apparatus 1. In the control unit 80, an operator can use the input device to input commands for managing the substrate processing apparatus 1. Furthermore, the operating status of the substrate processing apparatus 1 can be visually displayed in the control unit 80 via the display device. The control unit 80 stores control programs and process data in its storage unit. The processor of the control unit 80 executes the control program to cause the substrate processing apparatus 1 to perform various processes. The processor of the control unit 80 executes the control program and controls each part of the substrate processing apparatus 1 according to the process data, thereby causing the substrate processing apparatus 1 to perform various processes, such as plasma processing methods.

[0047] Furthermore, the control unit 80 controls the first cooling device 21a connected to the first flow path 18f of the first plate 18 and the second cooling device 21b connected to the second flow path 16f of the second plate 16. The temperature of the substrate W is adjusted by heat exchange between the heat transfer medium flowing in the first flow path 18f and the first plate 18, and by heat exchange between the heat transfer medium flowing in the second flow path 16f and the second plate 16. The temperature of the substrate W is also adjusted by heat exchange between the first plate 18 and the second plate 16, and by heat exchange between the first plate 18 and the electrostatic chuck 20.

[0048] Furthermore, in the mounting stage 14 of this structure, not only is a first flow path 18f provided on the first plate 18, but a second flow path 16f is also provided on the second plate 16, thereby enabling the temperature of the first plate 18 and the temperature of the second plate 16 to be controlled separately. This allows for proactive control of the deformation of the mounting stage 14. In addition, the control of the deformation of the mounting stage 14 also includes ensuring its flatness.

[0049] [Stage shape control]

[0050] Reference Figure 2 and Figure 3 This will illustrate an example of shape control of the stage 14 by temperature control of the stage 14 as described in the embodiment. Figure 2 and Figure 3 This is a diagram illustrating an example of temperature control of the stage 14 according to the embodiment. Figure 2 and Figure 3 The screw 19 engages with a threaded hole 19b formed on the upper surface of the outer periphery of the second plate 16 via a through hole 19a formed on the outer periphery of the first plate 18 and passing through the first plate 18. The screw 19 is used to thread the first plate 18 and the second plate 16 together across the contact surfaces of the two plates, thereby securing the first plate 18 and the second plate 16 together. Alternatively, a through hole can be provided in the second plate 16, and a threaded hole can be formed on the lower surface of the first plate for threaded fastening.

[0051] The first plate 18 and the second plate 16 are securely fastened together by screws 19. Therefore, when the temperature of the first plate 18 or the second plate 16 changes, thermal stress is generated in the first plate 18 or the second plate 16.

[0052] For example, such as Figure 2 As shown in (a), the temperature of the first plate 18 is controlled by maintaining the heat transfer medium flowing in the first flow path 18f at 0°C, and the temperature of the second plate 16 is controlled by maintaining the heat transfer medium flowing in the second flow path 16f at -100°C. Next, as... Figure 2 As shown in (b), the temperature of the second plate 16 is controlled by maintaining the temperature of the heat transfer medium flowing in the first flow path 18f at 0°C and controlling the temperature of the heat transfer medium flowing in the second flow path 16f at 100°C.

[0053] Thus, from Figure 2 The state of (a) changes to Figure 2In state (b), the temperature of the second plate 16 changes from -100°C to 100°C, while the temperature of the first plate 18 remains constant at 0°C. Therefore, the second plate 16 expands in both the vertical and horizontal directions compared to the first plate 18. The first plate 18 and the second plate 16 are securely fastened together by screws 19. Therefore, the horizontal expansion of the second plate 16 is hindered, and thermal stress (compressive stress) is generated in the second plate 16. Additionally, the first plate 18 experiences tensile stress, and both the electrostatic chuck 20 and the first plate 18 deform concavely towards the substrate mounting surface 20a.

[0054] Next, refer to Figure 3 This explains the temperature control when the electrostatic chuck 20 is deformed convexly toward the substrate mounting surface 20a. For example... Figure 3 As shown in (a), the temperature of the first plate 18 is controlled by controlling the heat transfer medium flowing in the first flow path 18f to 0°C, and the temperature of the second plate 16 is controlled by controlling the heat transfer medium flowing in the second flow path 16f to 100°C. Next, as... Figure 3 As shown in (b), the temperature of the heat transfer medium flowing in the first flow path 18f is maintained at 0°C, and the temperature of the heat transfer medium flowing in the second flow path 16f is controlled at -100°C to control the temperature of the second plate 16.

[0055] Thus, from Figure 3 The state of (a) changes to Figure 3 In state (b), the temperature of the second plate 16 changes from 100°C to -100°C, while the temperature of the first plate 18 remains constant at 0°C. Therefore, the second plate 16 contracts in both the vertical and horizontal directions compared to the first plate 18. The first plate 18 and the second plate 16 are securely fastened together by screws 19. Therefore, the horizontal contraction of the second plate 16 is hindered, and thermal stress (tensile stress) is generated in the second plate 16. Additionally, the first plate 18 experiences compressive stress, and the electrostatic chuck 20 and the first plate 18 deform convexly toward the substrate mounting surface 20a. Thus, the mounting stage 14 can be actively warped in the direction of warping of the substrate W according to the warping of the substrate W.

[0056] Furthermore, since the first plate 18 and the second plate 16 are firmly fastened together by screws 19, a strong frictional force is generated between the lower surface of the first plate 18 and the upper surface of the second plate 16. However, when the temperature of the first plate 18 or the second plate 16 changes rapidly, tensile stress (or compressive stress) stronger than the frictional force is rapidly generated, thus causing slippage. Therefore, sometimes the first plate 18 or the second plate 16 does not deform. Therefore, in order to control the deformation of the substrate mounting surface 20a, it is desirable to control the temperature of the first plate 18 or the second plate 16 within a range that does not generate strong thermal stress. Specifically, it is desirable to heat up or cool down in a manner that keeps the temperature difference between the first plate 18 and the second plate 16 below 3°C / minute.

[0057] Thus, in this embodiment, by controlling the temperature of the heat transfer medium in the second flow path 16f, the deformation of the mounting stage 14 can be actively controlled. For example, if it is desired to warp the mounting stage 14 in the same direction as the substrate W, the warping of the substrate W can be measured, and the mounting stage 14 can be actively warped in the direction of warping of the substrate W based on the measured result.

[0058] Furthermore, in this embodiment, the temperature of the heat transfer medium in the first flow path 18f is not changed. That is, the temperature of the first plate 18 is fixed at a temperature suitable for the process, while the temperature of the second plate 16 is varied, thereby enabling free control of the shape of the substrate mounting surface 20a.

[0059] The temperature control method described in this embodiment includes a step of measuring the shape of the substrate W, and a step of controlling the temperature of the heat transfer medium flowing in the second flow path 16f of the second plate 16 based on the measured shape of the substrate W. According to this temperature control method, temperature adjustment mechanisms are provided on both the first plate 18 and the second plate 16, thereby enabling active control of the deformation of the mounting stage 14 according to the shape of the substrate W. This allows the substrate mounting surface 20a of the electrostatic chuck 20 to deform in the warping direction of the substrate W, improving the adhesion between the substrate W and the electrostatic chuck 20, and thus improving the temperature controllability of the substrate W. This reduces the in-plane temperature distribution of the substrate, improving the etching characteristics (etching rate, etc.) of the substrate W. Furthermore, regarding the shape of the substrate W, the warping of the substrate W placed on the transport arm can be measured based on the state of the reflected laser light, the shape of the substrate W can be estimated by measuring the state of the contact surface of the substrate W placed on the transport arm, or other known methods can be used to determine the shape of the substrate W.

[0060] [Stage shape control (other examples)]

[0061] Next, refer to Figure 5 and Figure 5 To illustrate other examples of shape control by temperature control of the stage 14 involved in the implementation, the following describes another example. Figure 4 and Figure 5 This is a diagram illustrating another example of temperature control of the stage 14 according to the embodiment.

[0062] For example, such as Figure 4 As shown in (a), the temperature of the first plate 18 is controlled by maintaining the heat transfer medium flowing in the first flow path 18f at 40°C, and the temperature of the second plate 16 is controlled by maintaining the heat transfer medium flowing in the second flow path 16f at 40°C. At this time, the substrate mounting surface 20a is flat. Next, as... Figure 4 As shown in (b), the temperature of the first plate 18 is controlled by maintaining the heat transfer medium flowing in the first flow path 18f at 20°C, and the temperature of the second plate 16 is controlled by maintaining the heat transfer medium flowing in the second flow path 16f at 80°C. Next, as... Figure 4 As shown in (c), the temperature of the heat transfer medium flowing in the second flow path 16f is kept constant at 80°C, while the temperature of the heat transfer medium flowing in the first flow path 18f is controlled at 40°C to control the first plate 18. Furthermore, as... Figure 4 As shown in (d), the temperature of the heat transfer medium flowing in the first flow path 18f is kept constant at 40°C, and the temperature of the heat transfer medium flowing in the second flow path 16f is controlled at 40°C to regulate the temperature of the second plate 16.

[0063] like Figure 4 As shown in (a), the first plate 18 and the second plate 16 are controlled to the same temperature. Furthermore, the substrate mounting surface 20a is flat at this time. In this state, as... Figure 4 As shown in (b), the temperature of the first plate 18 is reduced from 40°C to 20°C. Meanwhile, the temperature of the second plate 16 is increased from 40°C to 80°C. As a result, the first plate 18 contracts, and the second plate 16 expands. Furthermore, the first plate 18 and the second plate 16 are securely fastened together by screws 19. Therefore, the horizontal expansion of the second plate 16 is hindered, and thermal stress (compressive stress) is generated in the second plate 16. In addition, tensile stress is generated in the first plate 18. And, the horizontal contraction of the first plate 18 is hindered, and thermal stress (tensile stress) is generated in the first plate 18. As a result, the electrostatic chuck 20 and the first plate 18 deform concavely toward the substrate mounting surface 20a.

[0064] Next, as Figure 4 As shown in (c), the temperature of the heat transfer medium flowing in the second flow path 16f is kept constant at 80°C, and the temperature of the heat transfer medium flowing in the first flow path 18f is controlled at 40°C to regulate the temperature of the first plate 18.

[0065] In this case, the first board 18 becomes the better choice. Figure 4The high temperature shown in (b) causes the first plate 18 to expand. The first plate 18 and the second plate 16 are securely fastened together by screws 19. Therefore, the horizontal expansion of the first plate 18 is hindered, and thermal stress (compressive stress) is generated in the first plate 18. Consequently, the electrostatic chuck 20 and the first plate 18 deform convexly toward the substrate mounting surface 20a. Figure 4 In the state shown in (b), the electrostatic chuck 20 and the first plate 18 are deformed concavely toward the substrate mounting surface 20a, therefore in Figure 4 In the state shown in (c), the substrate mounting surface 20a becomes approximately flat.

[0066] Next, as Figure 4 As shown in (d), the temperature of the heat transfer medium flowing in the first flow path 18f is kept constant at 40°C, and the temperature of the heat transfer medium flowing in the second flow path 16f is controlled at 40°C to control the temperature of the second plate 16.

[0067] In this case, the second board 16 becomes the better choice. Figure 4 The temperature is low as shown in state (c), therefore the second plate 16 contracts. The first plate 18 and the second plate 16 are firmly fastened together by screws 19. Therefore, the horizontal contraction of the second plate 16 is hindered, and the second plate 16 generates thermal stress (tensile stress). In addition, the first plate 18 generates compressive stress, and the electrostatic chuck 20 and the first plate 18 deform convexly toward the substrate mounting surface 20a.

[0068] Next, refer to Figure 5 This illustrates an example of temperature control when the electrostatic chuck 20 is deformed concavely toward the substrate mounting surface 20a. For example... Figure 5 As shown in (a), the temperature of the first plate 18 is controlled by maintaining the heat transfer medium flowing in the first flow path 18f at 40°C, and the temperature of the second plate 16 is controlled by maintaining the heat transfer medium flowing in the second flow path 16f at 40°C. At this time, the substrate mounting surface 20a is flat. Next, as... Figure 5 As shown in (b), the temperature of the first plate 18 is controlled by maintaining the heat transfer medium flowing in the first flow path 18f at 80°C, and the temperature of the second plate 16 is controlled by maintaining the heat transfer medium flowing in the second flow path 16f at 0°C. Next, as... Figure 5 As shown in (c), the temperature of the heat transfer medium flowing in the second flow path 16f is kept constant at 0°C, while the temperature of the heat transfer medium flowing in the first flow path 18f is controlled at 40°C to control the temperature of the first plate 18. Furthermore, as... Figure 5 As shown in (d), the temperature of the heat transfer medium flowing in the first flow path 18f is kept constant at 40°C, and the temperature of the heat transfer medium flowing in the second flow path 16f is controlled at 40°C to control the temperature of the second plate 16.

[0069] like Figure 5 As shown in (a), the first plate 18 and the second plate 16 are controlled to the same temperature. Furthermore, the substrate mounting surface 20a is flat. In this state, as... Figure 5 As shown in (b), the temperature of the first plate 18 is increased from 40°C to 80°C. Meanwhile, the temperature of the second plate 16 is decreased from 40°C to 0°C. The first plate 18 expands, and the second plate 16 contracts. Furthermore, the first plate 18 and the second plate 16 are securely fastened together by screws 19. Therefore, the horizontal contraction of the second plate 16 is hindered, and the second plate 16 generates thermal pressure (tensile stress). In addition, the first plate 18 generates compressive pressure. And, the horizontal expansion of the first plate 18 is hindered, and the first plate 18 generates thermal pressure (compressive pressure). As a result, the electrostatic chuck 20 and the first plate 18 deform convexly toward the substrate mounting surface 20a.

[0070] Next, as Figure 5 As shown in (c), the temperature of the heat transfer medium flowing in the second flow path 16f is kept constant at 0°C, and the temperature of the heat transfer medium flowing in the first flow path 18f is controlled at 40°C to control the temperature of the first plate 18.

[0071] In this case, the first board 18 becomes the better choice. Figure 5 The low temperature shown in (b) causes the first plate 18 to shrink. The first plate 18 and the second plate 16 are securely fastened together by screws 19. Therefore, the horizontal shrinkage of the first plate 18 is hindered, and thermal stress (tensile stress) is generated in the first plate 18. Consequently, the electrostatic chuck 20 and the first plate 18 deform concavely towards the substrate mounting surface 20a. Figure 5 In the state shown in (b), the electrostatic chuck 20 and the first plate 18 are deformed convexly toward the substrate mounting surface 20a, therefore in Figure 5 In the state shown in (c), the substrate mounting surface 20a becomes approximately flat.

[0072] Next, as Figure 5 As shown in (d), the temperature of the heat transfer medium flowing in the first flow path 18f is kept constant at 40°C, and the temperature of the heat transfer medium flowing in the second flow path 16f is controlled at 40°C to control the temperature of the second plate 16.

[0073] In this case, the second board 16 becomes the better choice. Figure 5 The high temperature shown in state (c) causes the second plate 16 to expand. The first plate 18 and the second plate 16 are securely fastened together by screws 19. Therefore, the horizontal expansion of the second plate 16 is hindered, and the second plate 16 generates thermal stress (compressive stress). Accompanying this, the first plate 18 generates tensile stress, and the electrostatic chuck 20 and the first plate 18 deform concavely toward the substrate mounting surface 20a.

[0074] In addition, Figure 4 In (b), to make the substrate mounting surface 20a concave, the temperature of the second plate 16 is increased and the temperature of the first plate 18 is decreased. However, the substrate mounting surface 20a can also be made concave by increasing the temperatures of both the first plate 18 and the second plate 16. For example, the temperature of the first plate 18 is increased from 40°C to 60°C, and the temperature of the second plate 16 is increased from 40°C to 80°C. In this case, the temperature change of the second plate 16 is greater than that of the first plate 18, and therefore the second plate 16 expands more significantly. As a result, the horizontal expansion of the second plate 16 is hindered, and thermal stress (compressive stress) is generated in the second plate 16. In addition, tensile stress is generated in the first plate 18. Thus, the substrate mounting surface 20a can be made concave. Alternatively, the temperature of the first plate 18 can be increased without changing the temperature of the second plate 16, or the temperature of the first plate 18 can be decreased without changing the temperature of the second plate 16.

[0075] In addition, to make the substrate mounting surface 20a convex, the temperatures of the first plate 18 and the second plate 16 can be increased in such a way that the temperature change of the first plate 18 is greater than the temperature change of the second plate 16. Alternatively, the temperature of the first plate 18 can be decreased without changing the temperature of the first plate 18, or the temperature of the first plate 18 can be increased without changing the temperature of the second plate 16.

[0076] In this embodiment, by controlling the temperature of the heat transfer medium in the first flow path 18f and / or the second flow path 16f, the deformation of the mounting stage 14 can be actively controlled. That is, the temperature changes of the first plate 18 and the second plate 16 are combined. Therefore, even if the temperatures of the first plate 18 and the second plate 16 are controlled to be similar to their initial state (… Figure 4 (a) or Figure 5 At the same temperature (a), the shape of the substrate mounting surface 20a can also be changed. Figure 4 (d) or Figure 5 (d)). Additionally, in Figure 4 and Figure 5 In the example, the shape of the substrate mounting surface 20a in the initial state is set to be flat, but it can also be concave or convex. That is, by adjusting the temperature of the first plate 18 and the second plate 16 according to the shape of the substrate mounting surface 20a in the initial state, the shape of the substrate mounting surface 20a can be arbitrarily changed regardless of the temperature of the first plate 18 and the second plate 16.

[0077] Various controls can be performed on the temperature control of the heat transfer medium flowing in the first flow path 18f and the heat transfer medium flowing in the second flow path 16f as described above. For example, the control unit 80 can control the temperature of the heat transfer medium flowing in the first flow path 18f and the heat transfer medium flowing in the second flow path 16f so that the first plate 18 and the second plate 16 reach the same temperature at the same time. Accordingly, the first plate 18 and the second plate 16 can reach the same temperature at the same time. Therefore, the mounting stage 14 will not deform due to the difference in thermal stress generated by the first plate 18 and the second plate 16. Furthermore, when only such control is performed, the first cooling device 21a and the second cooling device 21b can be the same cooling device. That is, the first cooling device 21a can be connected to both the first flow path 18f and the second flow path 16f, and the second cooling device 21b can be omitted.

[0078] [Temperature Control Method]

[0079] Next, refer to Figure 6 This will explain the temperature control method involved in the implementation method. Figure 6 This is a diagram illustrating an example of a temperature control method involved in the implementation method.

[0080] When this process begins, the control unit 80 acquires shape information of the substrate mounting surface 20a (step S1). The shape information of the substrate mounting surface 20a can be acquired by measuring using a sensor. Alternatively, the shape information can be acquired by referring to the historical records of temperature changes of the first plate 18 and the second plate 16 stored in the storage unit, as well as information indicating the correlation between the temperature changes of the first plate 18 and the second plate 16 and the shape changes of the first plate.

[0081] Next, the control unit 80 acquires the temperatures of the first plate 18 and the second plate 16 (step S2). The temperatures of the first plate 18 and the second plate 16 can be the temperatures of the heat transfer medium flowing in the first flow path 18f and the heat transfer medium flowing in the second flow path 16f, respectively. Alternatively, they can be the temperatures measured by temperature sensors respectively installed on the first plate 18 and the second plate 16.

[0082] Next, the control unit 80 acquires information about the warping of the substrate W (step S3). The information about the warping of the substrate W can be obtained by using information measured by a measuring device different from the substrate processing apparatus 1, or by using information measured by a measuring unit provided inside the substrate processing apparatus 1.

[0083] Next, the control unit 80 determines whether to change the shape of the mounting stage 14 (substrate mounting surface 20a) (step S4). The determination of whether to change the shape of the mounting stage 14 can be based on the shape information of the substrate mounting surface 20a obtained in step S1 and the warping information of the substrate W obtained in step S3.

[0084] In step S4, if the control unit 80 determines that the shape of the stage 14 will not change, it controls the first plate 18 and the second plate 16 to the same temperature (step S5), and ends the process. That is, the temperature of the heat transfer medium flowing in the first flow path 18f and the temperature of the heat transfer medium flowing in the second flow path 16f are controlled to be the same temperature or to a given temperature taking into account the heat input from the plasma, and the control is performed so that no temperature difference occurs between the first plate 18 and the second plate 16.

[0085] In step S4, if the control unit 80 determines that the shape of the mounting stage 14 needs to be changed, it controls the temperature of the first plate 18 and / or the second plate 16 (step S6) and ends the process. After step S6, a sensor can also be used to confirm whether the substrate mounting surface 20a has been deformed into the desired shape.

[0086] [Shape Measurement]

[0087] Next, refer to Figure 7 This illustrates an example of determining the shape of the first plate 18 and controlling the temperature of the heat transfer medium flowing in the first flow path 18f and / or the heat transfer medium flowing in the second flow path 16f based on the determination results. Figure 7 This is a diagram illustrating an example of the configuration of multiple sensors involved in an implementation method.

[0088] The stage 14 described in the embodiment may also have multiple sensors for measuring the shape of the first plate 18. For example... Figure 7 As shown in (a), as an example of multiple sensors, multiple strain gauges 81 and 82 are provided on the mounting stage 14. Figure 7 In example (a), multiple strain gauges 81 are attached to the upper surface 18a of the first plate 18 (the lower surface of the electrostatic chuck 20). Additionally, multiple strain gauges 82 are attached to the lower surface 18b of the first plate 18. The multiple strain gauges 81 can be disposed within an adhesive layer (not shown) between the first plate 18 and the electrostatic chuck 20. Multiple contraction and expansion values ​​measured by the multiple strain gauges 81 and 82 are sent to the control unit 80. The control unit 80 determines the shape of the first plate 18 based on the measured contraction and expansion values. Since the surface shape of the electrostatic chuck 20 varies according to the shape of the first plate 18, the surface shape of the electrostatic chuck 20 can be estimated by measuring the shape of the first plate 18.

[0089] The control unit 80 controls the temperature of the heat transfer medium in the first flow path 18f of the first plate 18 and / or the temperature of the heat transfer medium in the second flow path 16f of the second plate 16 based on the measured shape of the first plate 18.

[0090] In this way, the temperature of the first plate 18 and / or the second plate 16 is fed back based on the surface shape of the first plate 18 estimated from the measurements of multiple strain gauges 81 and 82. Thus, by controlling the temperature regulation of at least one plate in real time, the surface shape of the first plate 18 (the surface shape of the electrostatic chuck 20) ​​can be actively controlled.

[0091] However, the configuration of multiple strain gauges 81, 82 is not limited to this. Multiple strain gauges 81, 82 can also be attached to at least one of the upper surface 18a and lower surface 18b of the first plate 18, or to the lower surface of the electrostatic chuck 20. Multiple strain gauges 81, 82 are an example of multiple strain sensors for measuring the shape of the first plate; these multiple strain sensors can be load sensors.

[0092] like Figure 7 As shown in (b), as an example of multiple sensors, multiple laser interferometers 83 can also be disposed on the stage 14. The multiple laser interferometers 83 are disposed below the second plate 16 and irradiate laser light onto the lower surface 18b of the first plate 18 through a through-hole 16a penetrating the second plate 16. The multiple laser interferometers 83 measure the distance from the lower surface of the first plate 18 based on the time it takes to receive light reflected from the lower surface 18b. The control unit 80 determines the shape of the first plate 18 based on the distances obtained from the multiple laser interferometers 83. Since the surface shape of the electrostatic chuck 20 follows the change in shape of the first plate 18, the surface shape of the electrostatic chuck 20 can be estimated by measuring the shape of the first plate 18.

[0093] The control unit 80 controls the temperature of the heat transfer medium in the first flow path 18f of the first plate 18 and / or the temperature of the heat transfer medium in the second flow path 16f of the second plate 16 based on the measured shape of the first plate 18.

[0094] In this way, the temperature of the first plate 18 and / or the second plate 16 is fed back based on the surface shape of the first plate 18 estimated from measurements of multiple laser interferometers 83. Thus, by controlling the temperature regulation of at least one plate in real time, the surface shape of the first plate 18 can be actively controlled.

[0095] At this time, with the focusing device and other irradiation equipment fixed as a reference, the change in its length corresponds to the change in the lower surface of the electrostatic chuck 20. By feeding back this change, the temperature of the heat transfer medium in the first flow path 18f of the first plate 18 and / or the temperature of the heat transfer medium in the second flow path 16f of the second plate 16 can be controlled in real time, thereby enabling active control of the surface shape of the electrostatic chuck 20.

[0096] The temperature control method of the stage 14 includes a step of measuring the shape of the first plate 18, and a step of controlling the temperature adjustment mechanism of the first plate 18 and / or the temperature adjustment mechanism of the second plate 16 based on the measured shape of the first plate 18.

[0097] In the above description, the temperature control mechanism of the first plate 18 and / or the temperature control mechanism of the second plate 16 are controlled in real time based on the measured shape of the first plate 18. However, it is not limited to this, and the shape of the first plate 18 may not be measured. For example, the shape of the first plate 18 may be estimated by referring to the historical records of temperature changes of the first plate 18 and the second plate 16 stored in the storage unit, as well as information indicating the correlation between the temperature changes of the first plate 18 and the second plate 16 and the shape changes of the first plate.

[0098] Information regarding the correlation between temperature changes of the first plate 18 and the second plate 16 and changes in the shape of the first plate can be obtained by measuring the relationship between changes in the shape of the first plate 18 and the temperatures of the first and second temperature control mechanisms and storing this information in a storage unit. The storage unit can be the memory of the control unit 80. The information regarding the correlation between the shape of the first plate and temperature changes can be information indicating the correlation between the shape of the first plate and temperature changes for making the shape of the first plate flat. Alternatively, it can be information indicating the correlation between the shape of the first plate and temperature changes for making the shape of the first plate concave. Alternatively, it can be information indicating the correlation between the shape of the first plate and temperature changes for making the shape of the first plate convex.

[0099] According to the temperature control method described above, the deformation of the mounting stage 14 can be controlled. It should be considered that the substrate processing apparatus 1, mounting stage 14, and temperature control method disclosed herein are illustrative in all respects and not restrictive. The above embodiments can be modified and improved in various ways without departing from the appended claims and their spirit. The matters described in the above embodiments can be adopted in other structures without contradiction, and can also be combined without contradiction.

[0100] For example, a plasma processing apparatus was described as an example of a substrate processing apparatus, but any apparatus that performs a prescribed process (such as film formation, etching, etc.) on a substrate is acceptable and is not limited to a plasma processing apparatus.

[0101] In addition, the substrate processing apparatus can also be an etching apparatus, a film forming apparatus, an ashing apparatus, a doping apparatus, etc. For example, the substrate processing apparatus can also be an ITO film forming apparatus using sputtering or a metal film forming apparatus using MOCVD.

[0102] The substrate processing apparatus disclosed herein can also be applied to any type of apparatus among atomic layer deposition (ALD) apparatus, capacitively coupled plasma (CCP) apparatus, inductively coupled plasma (ICP) apparatus, radial line slot antenna (RLSA) apparatus, electron cyclotron resonance plasma (ECR) apparatus, and helicon wave plasma (HWP) apparatus.

Claims

1. A substrate processing apparatus comprising a mounting stage for mounting a substrate and a control unit, wherein, The mounting stage has: First board; A first temperature regulating mechanism controls the temperature of the first plate; The second plate is disposed below the first plate; The second temperature regulating mechanism controls the temperature of the second plate; as well as Fastening components that fasten the first plate and the second plate together. The control unit is configured to control the first temperature regulating mechanism and the second temperature regulating mechanism. The control unit controls the first temperature regulating mechanism and the second temperature regulating mechanism to ensure that the first plate and the second plate are at the same temperature at the same timing.

2. The substrate processing apparatus according to claim 1, characterized in that, In the mounting stage, a substrate is placed on an electrostatic chuck disposed on the upper part of the first plate.

3. The substrate processing apparatus according to claim 2, characterized in that, It also has a sensor for determining the shape of the first plate.

4. The substrate processing apparatus according to claim 3, characterized in that, The sensor is a plurality of strain sensors disposed on at least one of the upper surface, lower surface and lower surface of the first plate and the lower surface of the electrostatic chuck, for measuring the shape of the first plate.

5. The substrate processing apparatus according to claim 3, characterized in that, The sensor is a plurality of laser interferometers disposed below the second plate and irradiating the lower surface of the first plate with laser light through a through hole in the second plate to determine the shape of the first plate.

6. The substrate processing apparatus according to any one of claims 1 to 5, characterized in that, The fastening member is a screw that is inserted into a threaded hole provided on the outer periphery of the first plate and the second plate to fasten the first plate and the second plate together.

7. The substrate processing apparatus according to any one of claims 1 to 5, characterized in that, The first plate and the second plate are made of the same type of metal.

8. A temperature control method for a mounting stage, the mounting stage comprising: a first plate; a first temperature regulating mechanism for controlling the temperature of the first plate; a second plate disposed below the first plate; a second temperature regulating mechanism for controlling the temperature of the second plate; and a fastening member for fastening the first plate and the second plate together, the temperature control method comprising the following steps: Step (a): Determine the shape of the substrate placed on the mounting stage; as well as Step (b) involves controlling either the first temperature regulating mechanism or the second temperature regulating mechanism based on the measured shape of the substrate. In step (b), the first temperature regulating mechanism or the second temperature regulating mechanism is controlled by referring to the historical records of temperature changes of the first plate and the second plate stored in the storage unit, as well as information indicating the correlation between the temperature changes of the first plate and the second plate and the shape changes of the first plate.

9. The temperature control method according to claim 8, characterized in that, Prior to step (b), there is also a step (c) for determining the shape of the first plate.

10. The temperature control method according to claim 9, characterized in that, In step (b), the first temperature regulating mechanism or the second temperature regulating mechanism is controlled based on the shape of the first plate determined by step (c).

11. The temperature control method according to any one of claims 8 to 10, characterized in that, After step (b), there is also a step (d) to determine the shape of the first plate.

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