Plasma processing apparatus

Abstract

To provide a plasma processing apparatus capable of reducing component cost.SOLUTION: A plasma processing apparatus comprising: a first member; a second member; and a fastening member configured to fasten the first member and the second member, wherein the first member is made of a material obtained by adding a negative thermal expansion material to a first base material, the second member is made of a second base material, and a linear expansion coefficient of the first base material is higher than a linear expansion coefficient of the second base material.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present disclosure relates to a plasma processing apparatus. [Background technology]

[0002] Patent Document 1 describes that the linear expansion coefficient of a solid material is reduced by adding a solid material that exhibits a negative linear expansion coefficient to a solid material that exhibits a positive linear expansion coefficient. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2021-014387 Summary of the Invention [Problem to be solved by the invention]

[0004] In one aspect, the present disclosure provides a plasma processing apparatus that reduces component costs. [Means for solving the problem]

[0005] In order to solve the above problem, according to one aspect, a plasma processing apparatus is provided, comprising a first member, a second member, and a fastening member that fastens the first member and the second member, wherein the first member is made of a material in which a negative thermal expansion material is added to a first base material, and the second member is made of a second base material, and the linear expansion coefficient of the first base material is higher than the linear expansion coefficient of the second base material. [Effects of the Invention]

[0006] According to one aspect, it is possible to provide a plasma processing apparatus that reduces component costs. [Brief explanation of the drawings]

[0007] [Figure 1] FIG. 1 is an example of a diagram for explaining a configuration example of a capacitively coupled plasma processing apparatus. [Figure 2] FIG. 10 is a cross-sectional view showing an example of a fixing structure of the base. DETAILED DESCRIPTION OF THE INVENTION

[0008] Hereinafter, embodiments of the present disclosure will be described with reference to the drawings. In the drawings, the same components are denoted by the same reference numerals, and redundant explanations may be omitted.

[0009] [Plasma processing system] An example of the configuration of a plasma processing system will be described below. Fig. 1 is an example of a diagram for explaining an example of the configuration of a capacitively coupled plasma processing apparatus 1.

[0010] The plasma processing system includes a capacitively coupled plasma processing device 1 and a controller 2. The capacitively coupled plasma processing device 1 includes a plasma processing chamber 10, a gas supply 20, a power supply 30, and an exhaust system 40. The plasma processing device 1 also includes a substrate support 11 and a gas inlet. The gas inlet is configured to introduce at least one process gas into the plasma processing chamber 10. The gas inlet includes a showerhead 13. The substrate support 11 is disposed within the plasma processing chamber 10. The showerhead 13 is disposed above the substrate support 11. In one embodiment, the showerhead 13 forms at least a portion of the ceiling of the plasma processing chamber 10. The plasma processing chamber 10 has a plasma processing space 10s defined by the showerhead 13, a sidewall 10a of the plasma processing chamber 10, and the substrate support 11. The plasma processing chamber 10 has at least one gas inlet for supplying at least one processing gas into the plasma processing space 10s and at least one gas outlet for exhausting gas from the plasma processing space 10s. The plasma processing chamber 10 is grounded. The showerhead 13 and the substrate support 11 are electrically insulated from the housing of the plasma processing chamber 10.

[0011] The substrate support 11 includes a main body 111 and a ring assembly 112. The main body 111 has a central region 111a for supporting a substrate W and an annular region 111b for supporting the ring assembly 112. A wafer is an example of a substrate W. The annular region 111b of the main body 111 surrounds the central region 111a of the main body 111 in a plan view. The substrate W is disposed on the central region 111a of the main body 111, and the ring assembly 112 is disposed on the annular region 111b of the main body 111 so as to surround the substrate W on the central region 111a of the main body 111. Therefore, the central region 111a is also called a substrate support surface for supporting the substrate W, and the annular region 111b is also called a ring support surface for supporting the ring assembly 112.

[0012] In one embodiment, the main body 111 includes a base 1110, an electrostatic chuck 1111, an insulating plate 1112, and an insulating support 1113. The base 1110 includes a conductive member. The conductive member of the base 1110 can function as a lower electrode. The electrostatic chuck 1111 is disposed on the base 1110. The electrostatic chuck 1111 includes a ceramic member 1111a and an electrostatic electrode 1111b disposed within the ceramic member 1111a. The ceramic member 1111a has a central region 111a. In one embodiment, the ceramic member 1111a also has an annular region 111b. Note that the annular region 111b may also be provided on another member surrounding the electrostatic chuck 1111, such as the annular electrostatic chuck or the annular insulating member. In this case, the ring assembly 112 may be disposed on the annular electrostatic chuck or the annular insulating member, or may be disposed on both the electrostatic chuck 1111 and the annular insulating member. Furthermore, at least one RF / DC electrode coupled to an RF (Radio Frequency) power supply 31 and / or a DC (Direct Current) power supply 32 (described later) may be disposed within the ceramic member 1111a. In this case, the at least one RF / DC electrode functions as a lower electrode. When a bias RF signal and / or a DC signal (described later) is supplied to the at least one RF / DC electrode, the RF / DC electrode is also called a bias electrode. Note that the conductive member of the base 1110 and the at least one RF / DC electrode may function as multiple lower electrodes. Alternatively, the electrostatic electrode 1111b may function as the lower electrode. Therefore, the substrate support 11 includes at least one lower electrode.

[0013] The insulating plate 1112 is made of an insulating material, has a disk shape, and is disposed so as to cover the lower surface of the base 1110. The insulating support member 1113 is made of an insulating material, has a cylindrical shape, and is disposed below the insulating plate 1112. The insulating plate 1112 and the insulating support member 1113 are disposed between the base 1110 serving as the lower electrode and a portion at ground potential (in the example of FIG. 1, the bottom wall of the plasma processing chamber 10). This insulates the base 1110 serving as the lower electrode from the portion at ground potential (the bottom wall of the plasma processing chamber 10). The base 1110 is fixed to the bottom wall of the plasma processing chamber 10 via the insulating plate 1112 and the insulating support member 1113. As will be described later with reference to FIG. 2, the base 1110 is detachably fixed (fastened) to the insulating plate 1112 and the insulating support member 1113 by bolts 1115 (see FIG. 2).

[0014] The ring assembly 112 includes one or more annular members. In one embodiment, the one or more annular members include one or more edge rings and at least one cover ring. The edge rings are formed of a conductive or insulating material, and the cover rings are formed of an insulating material.

[0015] The substrate support 11 may also include a temperature adjustment module configured to adjust at least one of the electrostatic chuck 1111, the ring assembly 112, and the substrate W to a target temperature. The temperature adjustment module may include a heater, a heat transfer medium, a flow path 1110a, or a combination thereof. A heat transfer fluid such as brine or a gas flows through the flow path 1110a. In one embodiment, the flow path 1110a is formed in the base 1110, and one or more heaters are disposed in the ceramic member 1111a of the electrostatic chuck 1111. The substrate support 11 may also include a heat transfer gas supply configured to supply a heat transfer gas to a gap between the backside of the substrate W and the central region 111a.

[0016] The showerhead 13 is configured to introduce at least one processing gas from the gas supply unit 20 into the plasma processing space 10s. The showerhead 13 has at least one gas supply port 13a, at least one gas diffusion chamber 13b, and multiple gas inlets 13c. The processing gas supplied to the gas supply port 13a passes through the gas diffusion chamber 13b and is introduced into the plasma processing space 10s from the multiple gas inlets 13c. The showerhead 13 also includes at least one upper electrode. In addition to the showerhead 13, the gas introduction unit may also include one or more side gas injectors (SGIs) attached to one or more openings formed in the sidewall 10a.

[0017] The gas supply unit 20 may include at least one gas source 21 and at least one flow controller 22. In one embodiment, the gas supply unit 20 is configured to supply at least one process gas from a corresponding gas source 21 to the showerhead 13 via a corresponding flow controller 22. Each flow controller 22 may include, for example, a mass flow controller or a pressure-controlled flow controller. Additionally, the gas supply unit 20 may include one or more flow modulation devices to modulate or pulse the flow rate of the at least one process gas.

[0018] The power supply 30 includes an RF power supply 31 coupled to the plasma processing chamber 10 via at least one impedance matching circuit. The RF power supply 31 is configured to supply at least one RF signal (RF power) to at least one lower electrode and / or at least one upper electrode. This generates a plasma from at least one process gas supplied to the plasma processing space 10s. Therefore, the RF power supply 31 can function as at least a part of a plasma generating unit configured to generate a plasma from one or more process gases in the plasma processing chamber 10. In addition, by supplying a bias RF signal to the at least one lower electrode, a bias potential is generated on the substrate W, thereby attracting ion components in the formed plasma to the substrate W.

[0019] In one embodiment, the RF power supply 31 includes a first RF generating unit 31a and a second RF generating unit 31b. The first RF generating unit 31a is coupled to at least one lower electrode and / or at least one upper electrode via at least one impedance matching circuit and is configured to generate a source RF signal (source RF power) for plasma generation. In one embodiment, the source RF signal has a frequency in the range of 10 MHz to 150 MHz. In one embodiment, the first RF generating unit 31a may be configured to generate multiple source RF signals having different frequencies. The generated one or more source RF signals are supplied to at least one lower electrode and / or at least one upper electrode.

[0020] The second RF generating unit 31b is coupled to at least one lower electrode via at least one impedance matching circuit and configured to generate a bias RF signal (bias RF power). The frequency of the bias RF signal may be the same as or different from the frequency of the source RF signal. In one embodiment, the bias RF signal has a frequency lower than the frequency of the source RF signal. In one embodiment, the bias RF signal has a frequency in the range of 100 kHz to 60 MHz. In one embodiment, the second RF generating unit 31b may be configured to generate multiple bias RF signals having different frequencies. The generated one or more bias RF signals are supplied to at least one lower electrode. In various embodiments, at least one of the source RF signal and the bias RF signal may be pulsed.

[0021] The power supply 30 may also include a DC power supply 32 coupled to the plasma processing chamber 10. The DC power supply 32 includes a first DC generator 32a and a second DC generator 32b. In one embodiment, the first DC generator 32a is connected to at least one lower electrode and configured to generate a first DC signal. The generated first bias DC signal is applied to the at least one lower electrode. In one embodiment, the second DC generator 32b is connected to at least one upper electrode and configured to generate a second DC signal. The generated second DC signal is applied to the at least one upper electrode.

[0022] In various embodiments, at least one of the first and second DC signals may be pulsed. In this case, a sequence of voltage pulses is applied to at least one lower electrode and / or at least one upper electrode. The voltage pulses may have a rectangular, trapezoidal, triangular, or combination thereof pulse waveform. In one embodiment, a waveform generator for generating a sequence of voltage pulses from the DC signal is connected between the first DC generator 32a and at least one lower electrode. Thus, the first DC generator 32a and the waveform generator constitute a voltage pulse generator. When the second DC generator 32b and the waveform generator constitute a voltage pulse generator, the voltage pulse generator is connected to at least one upper electrode. The voltage pulses may have either positive or negative polarity. Furthermore, the sequence of voltage pulses may include one or more positive voltage pulses and one or more negative voltage pulses within one period. The first and second DC generating units 32a and 32b may be provided in addition to the RF power supply 31, or the first DC generating unit 32a may be provided instead of the second RF generating unit 31b.

[0023] The exhaust system 40 may be connected to, for example, a gas exhaust port 10e provided at the bottom of the plasma processing chamber 10. The exhaust system 40 may include a pressure regulating valve and a vacuum pump. The pressure regulating valve regulates the pressure in the plasma processing space 10s. The vacuum pump may include a turbomolecular pump, a dry pump, or a combination thereof.

[0024] The control unit 2 processes computer-executable instructions that cause the plasma processing apparatus 1 to perform various processes described in this disclosure. The control unit 2 may be configured to control each element of the plasma processing apparatus 1 to perform various processes described herein. In one embodiment, part or all of the control unit 2 may be included in the plasma processing apparatus 1. The control unit 2 may include a processing unit 2a1, a storage unit 2a2, and a communication interface 2a3. The control unit 2 may be implemented by, for example, a computer 2a. The processing unit 2a1 may be configured to read a program from the storage unit 2a2 and execute the read program to perform various control operations. The program may be stored in the storage unit 2a2 in advance or may be acquired via a medium when needed. The acquired program is stored in the storage unit 2a2 and read from the storage unit 2a2 by the processing unit 2a1 for execution. The medium may be various storage media readable by the computer 2a or a communication line connected to the communication interface 2a3. The processing unit 2a1 may be a CPU (Central Processing Unit). The storage unit 2a2 may include a random access memory (RAM), a read only memory (ROM), a hard disk drive (HDD), a solid state drive (SSD), or a combination thereof. The communication interface 2a3 may communicate with the plasma processing apparatus 1 via a communication line such as a local area network (LAN).

[0025] Next, a structure for fixing the base 1110 (first member) and the insulating members (insulating plate 1112, insulating support portion 1113) (second member) with bolts 1115 (fastening members) will be described with reference to Fig. 2. Fig. 2 is an example of a cross-sectional view showing the fixing structure of the base 1110.

[0026] The base 1110 has a base main body 1110b and a thermally sprayed film 1110c. The base main body 1110b is made of a material in which a negative thermal expansion material is added to a first base material.

[0027] The first base material is, for example, a metal material. The first base material is preferably a metal material other than copper and copper alloys. Specifically, the first base material is, for example, aluminum (Al(A5052)) with a linear expansion coefficient of 23.8×10 -6 [ / K]), titanium (Ti linear expansion coefficient: 8.4 × 10 -6 [ / K]) etc. The first base material is a material having a higher linear expansion coefficient than the second base material described below.

[0028] A negative thermal expansion material is a material that has a negative (minus) linear expansion coefficient. An example of a negative thermal expansion material is zirconium tungstate (ZrW2O8), whose linear expansion coefficient is -4 to -9 × 10 -6 [ / K]) etc. can be used.

[0029] When zirconium tungstate is used as the negative thermal expansion material, the chemical formula changes at temperatures above 600°C. For this reason, it is preferable to add the negative thermal expansion material to the first base material at temperatures below 600°C.

[0030] A plasma-resistant sprayed film 1110c is formed on the surface of the base body 1110b. The sprayed film 1110c is made of an insulating film. Specifically, the sprayed film 1110c is made of a film formed by spraying yttria (Y2O3), alumina (Al2O3), or the like.

[0031] Furthermore, a through hole 1110d and a countersunk hole 1110e are formed in the base 1110. The countersunk hole 1110e is formed in the upper surface of the base 1110, and is a hole into which the head of the bolt 1115 is accommodated when the bolt is fastened. The through hole 1110d passes from the bottom surface of the countersunk hole 1110e to the lower surface of the base 1110 (the surface facing the insulating plate 1112), and is a hole into which the shank of the bolt 1115 is inserted when the bolt is fastened.

[0032] The insulating plate 1112 is made of a second base material. From the viewpoint of mechanical strength and insulating properties, the second base material is made of alumina ceramics (Al2O3, linear expansion coefficient: 7.2 × 10 -6[ / K]) is used. Here, the second base material is a material having a lower linear expansion coefficient than the first base material.

[0033] A through-hole 1112a is formed in the insulating plate 1112. The through-hole 1112a penetrates from the upper surface (the surface facing the base 1110) to the lower surface (the surface facing the insulating support part 1113) of the insulating plate 1112, and is a hole through which the shank of the bolt 1115 is inserted when the bolt is fastened.

[0034] The insulating support part 1113 is made of a second base material, similar to the insulating plate 1112. The second base material is made of alumina ceramics (Al2O3, linear expansion coefficient: 7.2 × 10) from the viewpoint of mechanical strength and insulation properties. -6 [ / K]) is used. Here, the second base material is a material having a lower linear expansion coefficient than the first base material.

[0035] A bushing insertion portion 1113a is formed in the insulating support portion 1113. The bushing insertion portion 1113a is formed on the upper surface of the insulating plate 1112 (the surface facing the insulating plate 1112), and is a hole into which the threaded bushing 1114 is inserted.

[0036] The threaded bushing 1114 has an internal thread formed therein that screws into an external thread formed on the shaft of the bolt 1115. The threaded bushing 1114 is inserted into the bushing insertion portion 1113a, and the outer peripheral surface of the threaded bushing 1114 and the inner peripheral surface of the bushing insertion portion 1113a are fixed with an adhesive.

[0037] The bolt 1115 has a head and a shaft. A male thread is formed on the shaft. The bolt 1115 is inserted through the through hole 1110d and the through hole 1112a and threadedly engaged with the threaded bushing 1114, thereby fixing the base 1110 and the insulating plate 1112 to the insulating support part 1113.

[0038] In the plasma processing apparatus 1 (see FIG. 1), when plasma is generated in the plasma processing space 10s and plasma processing is performed on a substrate W, heat from the plasma is input to the substrate support 11. This causes thermal expansion of the substrate support 11 (base 1110, insulating plate 1112, insulating support 1113, etc.). The substrate support 11 is formed to be larger in the radial direction than in the height direction (thickness direction). Therefore, the substrate support 11 thermally expands more in the radial direction than in the height direction.

[0039] Here, the base 1110 (base main body 1110b) is made of a first base material (for example, aluminum (A5052)) with a linear expansion coefficient of 23.8×10 -6 [ / K]), and the insulating plate 1112 and the insulating support part 1113 are made of a second base material (for example, alumina ceramics (Al2O3) linear expansion coefficient: 7.2 × 10 -6 [ / K]) will be described as an example. Heat from the plasma is input to the substrate support part 11, causing thermal expansion of the base 1110, the insulating plate 1112, and the insulating support part 1113. If there is a large difference in the thermal expansion coefficient between the base 1110 and the insulating plate 1112 and the insulating support part 1113, the relative position of the central axis of the through hole 1110d will be shifted with respect to the central axes of the threaded bushing 1114 and the through hole 1112a. This may cause the bolt 1115 to break.

[0040] It is also possible to apply a thrust structure to the threaded bush that allows it to move in the radial direction of the base 1110. This allows the threaded bush that threads into the bolt 1115 to move in the radial direction in response to the difference in thermal expansion, preventing the bolt 1115 from breaking. On the other hand, when fastening with the bolt 1115, the threaded bush is free to move in the radial direction, which complicates the alignment of the base 1110 with respect to the insulating plate 1112, the alignment of the moving threaded bush, etc., reducing the workability of assembling the substrate support unit 11. Furthermore, providing a thrust structure to the threaded bush increases the manufacturing cost of the substrate support unit 11.

[0041] In contrast, in the plasma processing apparatus 1 according to this embodiment, by using a material in which a negative thermal expansion material is added to a first base material for the base main body portion 1110b of the base 1110 (first member), the linear expansion coefficient of the material of the base main body portion 1110b can be made closer to the linear expansion coefficient of the second base material.

[0042] As a result, the plasma processing apparatus 1 according to this embodiment can suppress misalignment of the central axis of the through hole 1110d with respect to the central axes of the threaded bushing 1114 and the through hole 1112a, even when plasma is generated in the plasma processing space 10s and the substrate support 11 becomes hot, thereby preventing the bolt 1115 from breaking.

[0043] Furthermore, in the plasma processing apparatus 1 according to this embodiment, the threaded bushing 1114 is fixed to the insulating support part 1113. Therefore, the plasma processing apparatus 1 according to this embodiment improves the workability of assembling the substrate support part 11 compared to a configuration in which a thrust structure is provided in the threaded bushing. Furthermore, in the plasma processing apparatus 1 according to this embodiment, the manufacturing cost of the substrate support part 11 can be reduced compared to a configuration in which a thrust structure is provided in the threaded bushing.

[0044] Next, the amount of negative thermal expansion material to be added will be described.

[0045] When the first base material to which the negative thermal expansion material (zirconium tungstate) is added is a metal material such as aluminum, the amount of powder of the negative thermal expansion material added to the first base material depends on the temperature difference ΔT between the first base material and the second member. In addition, the amount of powder of the negative thermal expansion material added to the first base material depends on the linear expansion coefficient of the second member.

[0046] (linear expansion coefficient of the first base material + linear expansion coefficient of the negative thermal expansion material × addition rate (%)) × ΔT (1)

[0047] The linear expansion coefficient of the first base material, for example, Al (A5052), is 23.8 × 10 -6The linear expansion coefficient of the negative thermal expansion material is, for example, -4 to -9 × 10 in the case of zirconium tungstate (ZrW2O8). -6 [ / K]. The addition rate (%) is the ratio of the mass of the negative thermal expansion material to the mass of the first base material. ΔT is the temperature difference between the first member (base 1110) and the second member (insulating plate 1112, insulating support part 1113).

[0048] If the above formula (1) is 0, the first member (base 1110) and the second member (insulating plate 1112, insulating support part 1113) will thermally expand equally. The amount of powder of the negative thermal expansion material added to the first base material is preferably such that the above formula (1) is close to 0.

[0049] The temperature of the first member (base 1110) is controlled by a temperature control module. When plasma is generated in the plasma processing space 10s, the first member (base 1110) is positioned closer to the plasma, and the second member (insulating plate 1112, insulating support 1113) is positioned farther from the plasma. This results in a temperature difference ΔT between the first member and the second member during plasma processing. This temperature difference ΔT also changes the amount of displacement due to thermal expansion of the first member and the second member. The amount of negative thermal expansion material added to the first base material is preferably determined so as to guarantee the amount of displacement due to the temperature difference. This allows the amount of displacement due to thermal expansion of the first member and the amount of displacement due to thermal expansion of the second member during plasma processing to be made closer to each other.

[0050] Furthermore, the negative thermal expansion material may be added so that the linear expansion coefficient of the first base material to which the negative thermal expansion material has been added is equal to the linear expansion coefficient of the second base material.

[0051] 2, the base material of the base 1110 is described as being formed from a metal material, but this is not limited thereto. The base material of the base 1110 may be a material other than a metal. Specifically, the base material (second base material) of the base 1110 (base main body portion 1110b) may be any of SiC, Si-SiC (composite ceramics of Si and SiC), etc. Furthermore, the base materials (first base materials) of the insulating plate 1112 and the insulating support portion 1113 may be alumina, etc. In this case, the base material (second base material) of the base 1110 is formed from a material with a lower linear expansion coefficient than the base materials (first base materials) of the insulating plate 1112 and the insulating support portion 1113. In such a configuration, by adding a negative thermal expansion material (for example, zirconium tungstate) to the first base material, the difference in thermal expansion between the base 1110 and the insulating plate 1112 and insulating support portion 1113 can be suppressed, and fracture of the bolt 1115 can be suppressed.

[0052] 2 illustrates an example of a structure in which the base 1110, the insulating plate 1112, and the insulating support portion 1113 are fixed together with bolts 1115, but the present invention is not limited thereto. The present invention may be applied to a structure in which the first member (base 1110) and the second member (insulating plate 1112 and insulating support portion 1113) are fixed together with bolts (bolts 1115) in the plasma processing apparatus 1. For example, the shower head 13 may have an electrode plate (second member) and a cooling plate (first member) that supports the electrode plate, and the electrode plate and the cooling plate may be fixed together with bolts. The first base material of the cooling plate (first member) is made of aluminum or the like. The second base material of the electrode plate (second member) is made of Si, SiO2, or the like. In this case, the linear expansion coefficient of the first base material is higher than the linear expansion coefficient of the second base material. Even in such a configuration, by adding a negative thermal expansion material (for example, zirconium tungstate) to the first base material, it is possible to suppress the difference in thermal expansion and prevent the bolt from breaking.

[0053] The above-disclosed embodiments include, for example, the following aspects. (Document title) Claims (Appendix 1) A first member; A second member; a fastening member that fastens the first member and the second member, the first member is made of a material in which a negative thermal expansion material is added to a first base material, the second member is made of a second base material, The linear expansion coefficient of the first base material is higher than the linear expansion coefficient of the second base material; Plasma processing equipment. (Appendix 2) The fastening member is a bolt having a head and a shank on which a male thread is formed, the first member has a through hole through which the shank of the fastening member is inserted when fastening; The second member has an internal thread that threadably engages with the external thread of the fastening member when fastened. 2. The plasma processing apparatus according to claim 1. (Appendix 3) the first base material is either aluminum or titanium, the second base material is an alumina ceramic; The negative thermal expansion material is zirconium tungstate. 10. The plasma processing apparatus according to claim 1 or 2. (Appendix 4) The first base material is either alumina, The second base material is SiC or Si-SiC, The negative thermal expansion material is zirconium tungstate. 10. The plasma processing apparatus according to claim 1 or 2. (Appendix 5) The first member and the second member are disposed in a plasma processing chamber that generates plasma. 5. The plasma processing apparatus according to claim 1, wherein the plasma processing apparatus is a plasma processing apparatus. (Appendix 6) the first member is a base of a substrate support; The second member is an insulating member that supports the base. 6. The plasma processing apparatus according to claim 5. (Appendix 7) the first member is an electrode plate, The second member is a cooling plate that supports the electrode plate. 6. The plasma processing apparatus according to claim 5. (Appendix 8) The linear expansion coefficient of the material obtained by adding the negative thermal expansion material to the first base material is equal to the linear expansion coefficient of the second base material. 8. The plasma processing apparatus according to claim 1, wherein the plasma processing apparatus is a plasma processing apparatus. (Appendix 9) the negative thermal expansion material is added based on a temperature difference between the first member and the second member when plasma is generated in the processing chamber. 8. The plasma processing apparatus according to claim 1, wherein the plasma processing apparatus is a plasma processing apparatus.

[0054] The present invention is not limited to the configurations described in the above embodiments, but may be combined with other elements, etc. These aspects can be changed without departing from the spirit of the present invention, and can be appropriately determined depending on the application form. [Explanation of symbols]

[0055] 1. Plasma processing equipment 2. Control section 10 Plasma Processing Chamber 11 Substrate support 13. Shower head 20 Gas supply unit 30 power supply 40 Exhaust System 1110 Foundation 1110b Base body part 1110c sprayed coating 1110e Counterbore 1110d through hole 1112 Insulation plate 1112a Through hole 1113 Insulation support part 1113a Bush insert 1114 Threaded bushing 1115 volts W substrate

Claims

1. A first member; A second member; a fastening member that fastens the first member and the second member, the first member is made of a material in which a negative thermal expansion material is added to a first base material, the second member is made of a second base material; The linear expansion coefficient of the first base material is higher than the linear expansion coefficient of the second base material. Plasma processing equipment.

2. The fastening member is a bolt having a head and a shank on which a male thread is formed, the first member has a through hole through which the shank of the fastening member is inserted during fastening; The second member has an internal thread that is threadably engaged with the external thread of the fastening member when fastened. The plasma processing apparatus according to claim 1 .

3. the first base material is either aluminum or titanium, the second base material is an alumina ceramic; The negative thermal expansion material is zirconium tungstate. The plasma processing apparatus according to claim 1 .

4. the first base material is alumina, the second base material is either SiC or Si—SiC, The negative thermal expansion material is zirconium tungstate. The plasma processing apparatus according to claim 1 .

5. The first member and the second member are disposed in a plasma processing chamber that generates a plasma. The plasma processing apparatus according to claim 1 .

6. the first member is a base of a substrate support; the second member is an insulating member that supports the base; The plasma processing apparatus according to claim 5 .

7. the first member is an electrode plate, The second member is a cooling plate that supports the electrode plate. The plasma processing apparatus according to claim 5 .

8. The linear expansion coefficient of the material obtained by adding the negative thermal expansion material to the first base material is equal to the linear expansion coefficient of the second base material. The plasma processing apparatus according to claim 1 .

9. the negative thermal expansion material is added based on a temperature difference between the first member and the second member when plasma is generated in the processing chamber. The plasma processing apparatus according to claim 1 .

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