Plasma processing device and mounting platform

Abstract

The present invention provides a stage and a plasma processing device, which improve the stability of the movement of a substrate arranged in a storage space in the stage. The stage includes: a base having a storage space inside; a dielectric layer provided on a first surface of the base and having a mounting surface for mounting the substrate, the dielectric layer having a plurality of heaters inside; and a heater control substrate arranged in the storage space and used to drive the plurality of heaters, the base having an inlet for introducing a refrigerant into the storage space on a second surface of the base opposite to the first surface.

Description

Technical Field

[0001] The present disclosure relates to a mounting table and a plasma processing apparatus. Background Art

[0002] There is known a mounting table for sucking a substrate in a processing apparatus for performing a desired process such as an etching process on the substrate.

[0003] Patent document 1 discloses a stage for a plasma processing device, the stage including: a power supply unit that provides a transmission path for high frequency transmission from a high frequency power source; an electrostatic chuck that has a plurality of heaters; and a heater controller. In addition, it is disclosed that the heater controller is disposed in a storage space surrounded by the transmission path.

[0004] Patent Document 1: Japanese Patent Application Publication No. 2018-206806 Summary of the invention

[0005] Problem that the invention aims to solve

[0006] In one aspect, the present disclosure provides a mounting table and a plasma processing apparatus that improve the stability of movement of a substrate disposed in a storage space within the mounting table.

[0007] Solutions for solving problems

[0008] In order to solve the above-mentioned problems, according to a technical solution, a mounting table is provided, which includes: a base having a storage space inside; a dielectric layer, which is arranged on the first surface of the base and has a mounting surface for mounting a substrate, and the dielectric layer has a plurality of heaters inside; and a heater control substrate, which is arranged in the storage space and is used to drive the plurality of heaters, and the base has an inlet for introducing a refrigerant into the storage space on the second surface of the base opposite to the first surface.

[0009] Effects of the Invention

[0010] According to one aspect, it is possible to provide a mounting table and a plasma processing apparatus that can improve the stability of movement of a substrate disposed in a storage space within the mounting table. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Figure 1 It is a schematic cross-sectional view showing an example of a substrate processing apparatus according to an embodiment.

[0012] Figure 2 It is a cross-sectional schematic diagram showing an example of a mounting table according to an embodiment.

[0013] Figure 3It is a perspective view showing an example of a diffusion member. DETAILED DESCRIPTION

[0014] Hereinafter, the mode for implementing the present disclosure will be described with reference to the drawings. In each of the drawings, the same components are denoted by the same reference numerals and overlapping descriptions may be omitted.

[0015] <Substrate processing equipment>

[0016] use Figure 1 A substrate processing apparatus (plasma processing apparatus) 1 according to an embodiment will be described. Figure 1 It is a schematic cross-sectional view showing an example of a substrate processing apparatus 1 according to an embodiment.

[0017] A substrate processing apparatus 1 according to one embodiment includes a processing container 10. The processing container 10 has a substantially cylindrical shape with a bottom, and is formed of, for example, aluminum with an anodized surface. The processing container 10 is grounded. A delivery port 10p for conveying a wafer (substrate) W is formed on a side wall of the processing container 10. The delivery port 10p is opened and closed by a gate valve 10g provided along the side wall of the processing container 10.

[0018] A support portion 11 is provided on the bottom of the processing container 10 . The support portion 11 is formed of an insulating material. The support portion 11 has a substantially cylindrical shape and extends upward from the bottom of the processing container 10 in the processing container 10 . The support portion 11 supports a mounting table 12 .

[0019] The mounting table 12 is provided in the processing container 10 and supported by the supporting portion 11. The mounting table 12 includes a base 13 and an electrostatic chuck 20. In addition, the base 13 includes a first portion 14 as a lower electrode and a second portion 15 as a transmission path for high frequency transmission. The first portion 14 and the second portion 15 are formed of a conductor such as aluminum. The first portion 14 and the second portion 15 are electrically connected. A storage space 17 for storing a heater control substrate 18 described later is formed in the base 13.

[0020] The electrostatic chuck 20 is provided on the first portion 14. A wafer W is placed on the upper surface of the electrostatic chuck 20. The electrostatic chuck 20 has a structure in which an electrode 20a formed of a conductive film is sandwiched between a dielectric layer 20b formed of a dielectric. A DC power supply 22 is connected to the electrode 20a. By applying a voltage from the DC power supply 22 to the electrode 20a, an electrostatic force such as a Coulomb force is generated, and the wafer W is adsorbed and held on the electrostatic chuck 20 by the electrostatic force.

[0021] In addition, the electrostatic chuck 20 has a plurality of heaters 21. The heaters 21 are connected to a DC power supply 23 via a heater control substrate 18. The heater control substrate 18 adjusts the temperature of each region of the mounting surface of the electrostatic chuck 20 by controlling the plurality of heaters 21 respectively, thereby adjusting the temperature of the wafer W mounted on the upper surface of the electrostatic chuck 20.

[0022] An edge ring 24 is disposed on the peripheral portion of the mounting table 12 so as to surround the edge of the wafer W. The edge ring 24 improves the in-plane uniformity of the plasma processing performed on the wafer W. The edge ring 24 can be formed of silicon, silicon carbide, quartz, or the like.

[0023] A flow path 16 is provided inside the first portion 14. A heat exchange medium (e.g., salt water or a gas-liquid two-phase fluid) is supplied to the flow path 16 from a cooling unit (not shown) provided outside the processing container 10 via a pipe 25a. The heat exchange medium supplied to the flow path 16 exchanges heat with the first portion 14. The heat exchange medium discharged from the flow path 16 returns to the cooling unit via a pipe 25b. Thus, the temperature of the wafer W placed on the electrostatic chuck 20 is adjusted.

[0024] The substrate processing apparatus 1 is provided with a gas supply line 26. The gas supply line 26 supplies a heat transfer gas (eg, He gas) from a heat transfer gas supply mechanism (not shown) to a position between the upper surface of the electrostatic chuck 20 and the back surface of the wafer W.

[0025] An upper electrode 30 is provided above the mounting table 12 so as to face the mounting table 12. A space between the upper electrode 30 and the mounting table 12 forms a plasma processing space.

[0026] The upper electrode 30 is provided in such a manner that the opening of the top of the processing container 10 is closed by means of an insulating shielding member 37. The upper electrode 30 comprises: an electrode plate 31, which constitutes an opposing surface opposite to the mounting table 12 and has a plurality of gas ejection holes 32; and an electrode support 33, which supports the electrode plate 31 so that it can be loaded and unloaded, and is formed of a conductive material, such as aluminum with an anodized surface. The electrode plate 31 is composed of silicon, SiC or other silicon-containing material. A gas diffusion chamber 34 is provided inside the electrode support 33, and a plurality of gas flow holes 35 connected to the gas ejection holes 32 extend downward from the gas diffusion chamber 34.

[0027] The electrode support 33 is provided with a gas inlet 36 for introducing gas into the gas diffusion chamber 34, and a gas supply pipe 40 is connected to the gas inlet 36, and a processing gas supply source 41 is connected to the gas supply pipe 40. A mass flow controller (MFC) 42 and an on-off valve 43 are provided in the gas supply pipe 40 in order from the upstream side where the processing gas supply source 41 is arranged. Then, the processing gas is ejected from the processing gas supply source 41 through the gas supply pipe 40, through the gas diffusion chamber 34, and the gas flow hole 35, and ejected from the gas ejection hole 32 in a spray shape.

[0028] A first high frequency power source 51 is connected to the second portion 15 of the mounting table 12 via a power supply rod 52 and a matching device 53. The first high frequency power source 51 applies HF (High Frequency) power to the mounting table 12. The matching device 53 matches the internal impedance of the first high frequency power source 51 with the load impedance. Thus, plasma is generated from the gas in the plasma processing space. In addition, HF power supplied from the first high frequency power source 51 may also be applied to the upper electrode 30. When HF power is applied to the mounting table 12, the frequency of HF may be in the range of 13 MHz to 100 MHz, for example, 40 MHz.

[0029] A second high frequency power source 54 is connected to the second portion 15 of the mounting table 12 via a power supply rod 55 and a matching device 56. The second high frequency power source 54 applies LF (Low Frequency) power to the mounting table 12. The matching device 56 matches the internal impedance of the second high frequency power source 54 with the load impedance. Thus, ions are attracted to the wafer W on the mounting table 12. The second high frequency power source 54 outputs high frequency power with a frequency in the range of 400kHz to 13.56MHz. A filter for grounding a predetermined high frequency may also be connected to the mounting table 12.

[0030] The frequency of LF is lower than that of HF. The voltage or current of LF and HF may be a continuous wave or a pulse wave. In this way, the showerhead for supplying gas functions as the upper electrode 30, and the mounting table 12 functions as the lower electrode.

[0031] An exhaust port 10e is provided at the bottom of the processing container 10, and an exhaust device 60 is connected to the exhaust port 10e via an exhaust pipe 62. The exhaust device 60 includes a vacuum pump such as a turbomolecular pump, and reduces the pressure in the processing container 10 to a desired vacuum level.

[0032] An annular baffle plate 61 is provided between the support portion 11 and the side wall of the processing container 10. The baffle plate 61 can be made of a material formed by coating an aluminum material with ceramic such as Y2O3.

[0033] When a predetermined process such as etching is performed in the substrate processing apparatus 1 of this structure, first, the gate valve 10g is opened, and the wafer W is introduced into the processing container 10 through the introduction and delivery port 10p and placed on the mounting table 12. Then, a gas for the predetermined process such as etching is supplied from the processing gas supply source 41 to the gas diffusion chamber 34 at a predetermined flow rate, and is supplied into the processing container 10 through the gas flow hole 35 and the gas ejection hole 32. In addition, the processing container 10 is exhausted by the exhaust device 60. Thus, the internal pressure is controlled to a set value within the range of, for example, 0.1Pa to 150Pa.

[0034] In the state where the predetermined gas is introduced into the processing container 10, HF power is applied to the mounting table 12 from the first high frequency power source 51. In addition, LF power is applied to the mounting table 12 from the second high frequency power source 54. In addition, a DC voltage is applied to the electrode 20a from the DC power source 22 to hold the wafer W on the mounting table 12. In addition, a DC voltage is applied to the heater 21 from the DC power source 23 to adjust the temperature of the wafer W.

[0035] The gas ejected from the gas ejection hole 32 of the upper electrode 30 is mainly dissociated and ionized by the high-frequency power of HF to become plasma, and the radicals and ions in the plasma are used to perform etching and other processes on the processing surface of the wafer W. In addition, by applying high-frequency power of LF to the mounting table 12, the ions in the plasma are controlled, and the etching and other processes are promoted.

[0036] The substrate processing device 1 is provided with a control unit 70 for controlling the overall operation of the device. The CPU provided in the control unit 70 performs the desired plasma processing such as etching according to the process stored in the memory such as ROM and RAM. In the process, the control information of the device for the process conditions, namely, the process time, pressure (gas exhaust), high-frequency power of HF and high-frequency power of LF, voltage, and various gas flow rates can be set. In addition, the temperature in the processing container (upper electrode temperature, side wall temperature of the processing container, wafer W temperature, electrostatic chuck temperature, etc.), the temperature of the refrigerator output from the cooling device, etc. can also be set in the process. In addition, the process representing these programs and processing conditions can also be stored in a hard disk or a semiconductor memory. In addition, the process can also be loaded at a specified position in a state of being contained in a storage medium such as a CD-ROM, DVD, etc. that can be read by a portable computer.

[0037] Next, use Figure 2 The mounting table 12 will be further described. Figure 2 It is a schematic cross-sectional view showing an example of the mounting table 12 according to one embodiment.

[0038] The first part 14 has a generally disk-like shape with a recess formed on the lower surface, and is formed of a conductive material, such as aluminum. The second part 15 has a generally disk-like shape with a recess formed on the upper surface, and is formed of a conductive material, such as aluminum. The second part 15 is fitted into the first part 14 to form the base 13, and a receiving space 17 is formed inside the base 13. In addition, the second part 15 is fitted into the first part 14 to electrically connect the second part 15 and the first part 14.

[0039] The electrostatic chuck 20 is provided on the first surface of the base 13 (the upper surface of the first portion 14). A terminal portion 15a is formed at the center of the second surface of the base 13 (the lower surface of the second portion 15), which is the surface opposite to the first surface. The power supply rods 52 and 55 (see FIG. 1 ) are connected to the terminal portion 15a. Figure 1 ) and apply a high frequency (HF, LF) to the terminal portion 15a. The high frequency applied from the terminal portion 15a is transmitted from the second portion 15 to the first portion 14 serving as the lower electrode.

[0040] The heater control board 18 is arranged in the storage space 17. The heater control board 18 is mounted with devices such as FETs, which are switching elements for switching the power supply of the plurality of heaters 21, FPGAs for controlling the switching elements, DC-DC converters, resistors, etc. Figure 1 ) supplies power to the heater control board 18 via a filter (not shown). Power supply lines are wired from the heater control board 18 to the heaters 21, respectively.

[0041] In this way, since the terminal portion 15a is provided at the center of the lower surface side of the second portion 15, the storage space 17 formed in the base 13 can be surrounded by the high-frequency transmission path. In addition, the heater control substrate 18 arranged in the storage space 17 surrounded by the high-frequency transmission path can distribute and switch the power supply to the plurality of heaters 21. Therefore, a filter for suppressing the high frequency from flowing from the mounting table 12 to the DC power supply 23 can be provided between the heater control substrate 18 and the DC power supply 23, and the number of filters can be reduced.

[0042] Here, for the substrate processing device 1, when plasma is generated to process the wafer W, the temperature of the wafer W and the temperature of the mounting table 12 become high temperatures due to the input heat from the plasma. The temperature of the wafer W is adjusted to, for example, 50°C to 150°C, and the temperature of the base 13 becomes, for example, 20°C to 100°C. Therefore, heat is input from the base 13 (located on the inner wall surface of the storage space 17) to the heater control substrate 18. In addition, the devices of the heater control substrate 18 also generate heat. Therefore, the characteristics of the devices (such as the switching characteristics of the FET, the resistance value of the resistor, etc.) may change. In addition, if the heat is excessive, it may cause device failure of the heater control substrate 18.

[0043] In addition, when the substrate processing apparatus 1 processes the wafer W at a low temperature, a low-temperature heat exchange medium is supplied to the flow path 16, so that the temperature of the wafer W and the temperature of the mounting table 12 are low. The temperature of the wafer W is adjusted to, for example, -100°C to 0°C, and the temperature of the base 13 is adjusted to, for example, -120°C to 0°C. Therefore, condensation may occur on the inner wall of the storage space 17, and the condensed water may adhere to the heater control substrate 18.

[0044] The mounting table 12 according to one embodiment has inlets 28a and 28b for introducing a refrigerant into the storage space 17 and an outlet 29 for discharging the refrigerant from the storage space 17. As the refrigerant, air sent from the DC fan 27 can be used. In addition, the refrigerant is not limited thereto, and may also be dry air, inert gas, etc. Thus, the heater control substrate 18 can be air-cooled. In addition, for the substrate processing device 1, when the wafer W is processed at a low temperature, the occurrence of condensation can be suppressed.

[0045] Here, the inlet ports 28a, 28b and the outlet port 29 are provided on the second surface of the base 13, that is, the second portion 15. Thus, compared with the case where the inlet ports and the outlet ports are provided on the side surface of the base 13, the symmetry of the high-frequency transmission path in the circumferential direction of the mounting table 12 can be ensured.

[0046] The introduction port 28a (first introduction port) is provided at a position not covered by the heater control substrate 18. In other words, when viewed from a direction perpendicular to the mounting surface of the mounting table 12, the introduction port 28a is provided at a position different from the position where the heater control substrate 18 is arranged. In addition, a diffusion member 80 is provided in the housing space 17 in a one-to-one correspondence with the introduction port 28a. Figure 3 The diffusion member 80 will be further described. Figure 3 It is a perspective view showing an example of the diffusion member 80 .

[0047] The diffusion member 80 has a shape with openings at the bottom and the front. The diffusion member 80 is formed of a material having heat resistance. In addition, the diffusion member 80 is formed of a material having low thermal conductivity. For example, it is formed of a resin material such as polyvinyl chloride (PVC) and polyphenylene sulfide (PPS).

[0048] The diffusion member 80 includes a back wall portion 81, an upper wall portion 82, and side walls 83 and 84. The back wall portion 81 is formed so as to extend upward. The upper wall portion 82 is formed so as to extend forward from the back wall portion 81. A fillet portion 85 is formed between the inner surface of the back wall portion 81 and the inner surface of the upper wall portion 82. Thus, the inner surface of the back wall portion 81 and the inner surface of the upper wall portion 82 become a continuous surface via the inner surface of the fillet portion 85.

[0049] The side walls 83 and 84 are formed so as to extend forward from the back wall 81. The inner walls of the side walls 83 and 84 are inclined outward at an angle θ relative to the front. That is, the interval between the inner wall of the side wall 83 and the inner wall of the side wall 84 is formed so as to expand from the rear side (the side of the back wall 81) to the front side (the side of the opening).

[0050] like Figure 2 As shown in FIG. 1 , the lower side of the open diffusion member 80 is arranged to correspond to the introduction port 28 a . In addition, the front side of the open diffusion member 80 is arranged to face the center of the accommodation space 17 .

[0051] The refrigerant supplied from the DC fan 27 is supplied from the inlet 28a to the upper direction of the storage space 17. The refrigerant supplied from the inlet 28a to the storage space 17 changes its direction along the inner surface of the back wall portion 81, the inner surface of the fillet portion 85, and the inner surface of the upper wall portion 82, thereby going to the center of the storage space 17. As a result, the refrigerant is supplied to the storage space 17 above the heater control substrate 18, that is, the space 17a. In addition, a part of the refrigerant is supplied to the storage space 17 below the heater control substrate 18, that is, the space 17b. In addition, since the inner walls of the side wall portions 83 and 84 are formed to expand from the rear side to the front side, the refrigerant flows in a manner that expands to a wide range. As a result, the refrigerant supplied from the inlet 28a to the storage space 17 expands in the entire storage space 17, thereby cooling the heater control substrate 18.

[0052] Furthermore, since the diffusion member 80 is formed of a material with low thermal conductivity, the refrigerant is prevented from being heated by the heat of the base 13. Furthermore, it is possible to prevent the first site 14 from being locally cooled by the refrigerant supplied from the introduction port 28a.

[0053] The introduction port 28b (second introduction port) is provided at a position covered by the heater control substrate 18. In other words, when viewed from a direction perpendicular to the mounting surface of the mounting table 12, the introduction port 28b is provided at a position overlapping with a position where the heater control substrate 18 is disposed. That is, the introduction port 28b is disposed below the heater control substrate 18. The refrigerant supplied from the DC fan 27 is supplied from the introduction port 28b upward into the housing space 17. The refrigerant supplied from the introduction port 28b into the housing space 17 is directly blown toward the heater control substrate 18, thereby cooling the heater control substrate 18. In addition, the heater control substrate 18 is cooled while flowing in the space 17b.

[0054] By blowing the refrigerant directly toward the heater control board 18 , it is possible to suppress the refrigerant supplied from the introduction port 28 b from cooling the first portion 14 locally.

[0055] The introduction port 28b may be provided at a position away from the introduction port 28a, for example. Thus, the refrigerant from the introduction port 28b can be supplied to a region where the cooling by the refrigerant from the introduction port 28a is low, thereby supplementing the cooling of the heater control board 18.

[0056] An insulating plate 90 is provided along the inner wall of the accommodation space 17. The insulating plate 90 is formed of a material having heat resistance. In addition, the insulating plate 90 is formed of a material having low thermal conductivity. For example, it is formed of a resin material such as polyvinyl chloride (PVC) and polyphenylene sulfide (PPS). The insulating plate 90 is provided along the inner wall of the accommodation space 17 on the upper surface of the accommodation space 17, that is, at a position of the first portion 14 on the side of the accommodation space 17. By providing the insulating plate 90, heat conduction from the first portion 14 to the heater control substrate 18 can be suppressed. In addition, for the substrate processing device 1, the occurrence of condensation can be suppressed when the wafer W is processed at a low temperature.

[0057] A gap 91 is provided between the upper surface of the housing space 17 and the heat insulating plate 90. Thus, heat conduction between the first site 14 and the heat insulating plate 90 is suppressed, and heat conduction from the first site 14 to the heater control substrate 18 can be further suppressed.

[0058] In addition, the heat insulating plate 90 is also provided along the inner wall of the housing space 17 on the lower surface of the housing space 17, that is, at a position of the second portion 15 close to the housing space 17. Thus, heat conduction from the second portion 15, which is heated or cooled by heat conduction from the joint portion with the first portion 14, to the heater control substrate 18 can be suppressed.

[0059] Furthermore, a gap portion 92 is provided between the lower surface of the housing space 17 and the heat insulating plate 90. Thus, heat conduction from the second portion 15 to the heater control substrate 18 can be further suppressed.

[0060] In addition, a water-absorbing sheet or a moisture-absorbing sheet may be attached to the heat-insulating plate 90 . This can further suppress the adhesion of condensed water to the heater control board 18 .

[0061] As described above, according to the mounting table 12 according to one embodiment, the heater control board 18 can be cooled preferably, so that the heater control board 18 can be operated stably. In addition, condensation can be prevented.

[0062] Although the embodiment and the like of the substrate processing apparatus 1 have been described above, the present disclosure is not limited to the above-described embodiment and the like, and various modifications and improvements can be made within the scope of the gist of the present disclosure described in the claims.

[0063] exist Figure 2In the figure, the number of the introduction ports 28a, 28b and the discharge port 29 is shown to be one each, but the present invention is not limited thereto and the number may be plural.

[0064] Although the case where the power source of the heater 21 is the DC power source 23 has been described, an AC power source may also be used.

Claims

1. A mounting platform, wherein: The mounting platform includes: A base having a first portion as a lower electrode and a second portion disposed to face the first portion, wherein a housing space is formed inside the base by the first portion and the second portion; a dielectric layer provided on the first surface of the first portion, having a mounting surface for mounting a substrate, the dielectric layer having a plurality of heaters therein; and a heater control substrate, which is arranged in the receiving space and is used to drive the plurality of heaters, The second portion has an inlet for introducing the refrigerant into the accommodation space on a second surface of the second portion which is opposite to the first surface.

2. The mounting table according to claim 1, wherein: The mounting platform includes a heat insulating plate, and the heat insulating plate is arranged in the receiving space.

3. The mounting table according to claim 2, wherein: The heat insulating plate is disposed between the inner wall surface of the accommodation space and the heater control substrate.

4. The mounting table according to claim 3, wherein: A gap portion is provided between an inner wall surface of the housing space on the first surface side and the heat insulating plate.

5. The mounting table according to any one of claims 1 to 4, wherein: The mounting table includes a diffusion member disposed in the housing space and causing the refrigerant introduced from the introduction port to diffuse in the housing space.

6. The mounting table according to claim 5, wherein: The diffusion member changes the direction of the flow of the refrigerant introduced from the introduction port so that the refrigerant flows between an inner wall surface of the housing space on the first surface side and the heater control substrate.

7. The mounting table according to claim 5, wherein: The diffusion member is formed to expand in the width direction toward the opening side.

8. The mounting table according to claim 5, wherein: The diffusion member is formed of a material having a lower thermal conductivity than that of the base.

9. The mounting table according to claim 5, wherein: The introduction port has a first introduction port, and the first introduction port is provided at a position different from a position where the heater control substrate is arranged when viewed in a direction perpendicular to the mounting surface. The diffusion member and the first introduction port correspond to each other one by one.

10. The mounting table according to any one of claims 1 to 4, wherein: The introduction port includes a second introduction port provided at a position overlapping with a position where the heater control substrate is arranged when viewed from a direction perpendicular to the mounting surface.

11. The mounting table according to any one of claims 1 to 4, wherein: The base has a discharge port for discharging the refrigerant from the accommodation space.

12. The mounting table according to any one of claims 1 to 4, wherein: The refrigerant is any one of air, dry air, and inert gas.

13. The mounting table according to any one of claims 1 to 4, wherein: The base has a flow path through which a heat transfer medium flows.

14. The mounting table according to claim 13, wherein: The heat transfer medium is salt water or a gas-liquid two-phase fluid.

15. A mounting platform, wherein: The mounting platform includes: a base having a receiving space therein; a dielectric layer provided on the first surface of the base, having a mounting surface for mounting the substrate, the dielectric layer having a plurality of heaters inside; a heater control substrate, which is disposed in the receiving space and is used to drive the plurality of heaters; an insulation board disposed in the receiving space; and a diffusion member disposed in the receiving space, The base has an inlet for introducing a refrigerant into the accommodation space on a second surface of the base which is opposite to the first surface. The heat insulating plate is disposed between the inner wall surface of the receiving space and the heater control substrate. A gap is provided between the inner wall surface of the accommodation space on the first surface side and the heat insulating plate, The diffusion member is configured to diffuse the refrigerant introduced from the introduction port in the accommodation space. The interval between the side wall portions of the diffusion member is formed to widen from the rear side of the diffusion member toward the front side of the diffusion member.

16. A plasma processing device, wherein: The plasma processing apparatus includes the mounting table according to any one of claims 1 to 15.

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