Substrate support, plasma processing apparatus, and method of manufacturing substrate support

Abstract

To suppress deterioration in in-plane uniformity of a substrate temperature.SOLUTION: A substrate support according to an exemplary embodiment includes a base having a through-hole penetrating in a thickness direction of the base, a support plate bonded to the base via an adhesive layer and having an opening aligned with the through-hole in the thickness direction, a sleeve covering an inner wall surface of the base defining the through-hole, a porous body disposed between the support plate and the sleeve, and an ionic liquid held in a void of the porous body.SELECTED DRAWING: Figure 5

Description

[Technical Field]

[0001] SUMMARY Exemplary embodiments of the present disclosure relate to a substrate support, a plasma processing apparatus, and a method for manufacturing a substrate support. [Background technology]

[0002] Patent Document 1 describes a substrate support for a plasma processing apparatus that supports a substrate. The substrate support includes a base, an electrostatic chuck disposed on the base, an alumina sleeve disposed within the base, and heat transfer gas supply holes defined by the sleeve, with the sleeve bonded to the electrostatic chuck via an adhesive layer. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2023-3957 Summary of the Invention [Problem to be solved by the invention]

[0004] In a plasma processing apparatus equipped with the substrate support described in Patent Document 1, when a substrate is processed, part of the plasma generated in the chamber may enter the heat transfer gas supply holes through the openings in the electrostatic chuck. In this case, part of the adhesive layer formed between the electrostatic chuck and the sleeve may be worn away by active species (ions or radicals) in the plasma. Because the adhesive layer functions to transfer heat between the electrostatic chuck and the sleeve, if the adhesive layer is worn away, the electrostatic chuck and the sleeve may partially become insulated by vacuum in a reduced-pressure environment, causing a localized increase in the temperature of the electrostatic chuck around the heat transfer gas supply holes. This may reduce the in-plane temperature uniformity of the substrate supported on the electrostatic chuck.

[0005] Therefore, the present disclosure provides a technique for suppressing a decrease in the in-plane uniformity of the substrate temperature. [Means for solving the problem]

[0006] A substrate support according to one exemplary embodiment includes a base having a through hole penetrating through its thickness, a support plate bonded to the base via an adhesive layer, the support plate having an opening aligned with the through hole in the thickness direction, a sleeve covering the inner wall surface of the base that defines the through hole, a porous body disposed between the support plate and the sleeve, and an ionic liquid held in the voids of the porous body. [Effects of the Invention]

[0007] According to one exemplary embodiment, it is possible to suppress a decrease in the in-plane uniformity of the substrate temperature. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 1 is a diagram illustrating an example of the configuration of a plasma processing system. [Figure 2] FIG. 1 is a diagram illustrating an example of the configuration of a capacitively coupled plasma processing apparatus. [Figure 3] 1 is a cross-sectional view of a substrate support according to an exemplary embodiment. [Figure 4] 1 is a cross-sectional view of a substrate support according to an exemplary embodiment. [Figure 5] FIG. 2 is an enlarged cross-sectional view of the substrate support showing the periphery of a gas supply hole. [Figure 6] A method for manufacturing a substrate support according to one exemplary embodiment will now be described. [Figure 7] 1(a) and 1(b) are diagrams showing an example of a method for injecting an ionic liquid into a porous body. DETAILED DESCRIPTION OF THE INVENTION

[0009] Various exemplary embodiments are described below.

[0010] A substrate support according to one exemplary embodiment includes a base having a through hole penetrating through its thickness, a support plate bonded to the base via an adhesive layer, the support plate having an opening aligned with the through hole in the thickness direction, a sleeve covering the inner wall surface of the base that defines the through hole, a porous body disposed between the support plate and the sleeve, and an ionic liquid held in the voids of the porous body.

[0011] In the substrate support according to the above embodiment, a porous body is disposed between the support plate and the sleeve, preventing the adhesive layer disposed between the base and the support plate from being exposed to the through-holes. This prevents the adhesive layer from being worn away by activated species of plasma that have entered the through-holes. Furthermore, an ionic liquid is held within the voids of the porous body, allowing heat conduction between the support plate and the sleeve via the ionic liquid. This prevents a decrease in the in-plane temperature uniformity of the support plate and the substrate supported thereon.

[0012] In one exemplary embodiment, the ionic liquid may have a saturated vapor pressure of 200 mTorr or less at 25° C. As described above, the low saturated vapor pressure of the ionic liquid allows the ionic liquid to be maintained in a liquid state even in a reduced pressure environment. Therefore, thermal conductivity between the support plate and the sleeve can be maintained even in a reduced pressure environment.

[0013] In one exemplary embodiment, the ionic liquid may have a thermal conductivity higher than that of helium gas. The high thermal conductivity of the ionic liquid promotes heat transfer between the support plate and the sleeve. As a result, the decrease in the in-plane temperature uniformity of the substrate can be effectively suppressed.

[0014] In one exemplary embodiment, the ionic liquid may comprise a pyrrolidinium salt, a pyridinium salt, an ammonium salt, or an imidazolium salt.

[0015] In one exemplary embodiment, the porous body may be a ceramic body having a porous structure. When the porous body is made of a ceramic body having radical resistance, the adhesive layer can be protected from active species such as radicals.

[0016] In one exemplary embodiment, the porous body may be a thermally sprayed ceramic coating.

[0017] In one exemplary embodiment, the porous body includes a first portion exposed to the through-holes and a second portion disposed between the first portion and the adhesive layer, and the bulk density of the second portion may be lower than the bulk density of the first portion. By relatively increasing the bulk density of the first portion, it is possible to suppress the intrusion of active species such as radicals between the support plate and the sleeve. Furthermore, by relatively decreasing the bulk density of the second portion, it is possible to allow the ionic liquid to penetrate into the interior of the porous body by capillary action.

[0018] In one exemplary embodiment, the amount of ionic liquid retained in the second portion may be greater than the amount of ionic liquid retained in the first portion.

[0019] In one exemplary embodiment, the support plate may be an electrostatic chuck that includes a ceramic body and an electrostatic electrode disposed within the body.

[0020] In one exemplary embodiment, the apparatus may further include a heat transfer gas supply configured to supply a heat transfer gas between the support plate and the substrate supported on the support plate through the through holes.

[0021] According to one exemplary embodiment, a plasma processing apparatus includes a chamber body and the above-described substrate support disposed within the chamber body. As described above, this plasma processing apparatus can suppress a decrease in the in-plane temperature uniformity of the substrate during plasma processing.

[0022] A method for manufacturing a substrate support according to one exemplary embodiment includes the steps of: preparing a substrate support, the substrate support comprising: a base having a through hole penetrating in its thickness direction; a support plate bonded to the base via an adhesive layer, the support plate having an opening aligned with the through hole; a sleeve covering an inner wall surface of the base that defines the through hole; and a porous body disposed between the support plate and the sleeve; and injecting an ionic liquid into the voids of the porous body.

[0023] In the manufacturing method according to the above embodiment, it is possible to manufacture a substrate support that can suppress a decrease in the in-plane uniformity of the substrate temperature.

[0024] In one exemplary embodiment, the step of injecting the ionic liquid may include the steps of inverting the substrate support so that the support plate is positioned below the base, sealing the opening of the support plate, and filling the through-holes with the ionic liquid to allow the ionic liquid to permeate the voids of the porous body. In this embodiment, the ionic liquid can be retained in the voids of the porous body.

[0025] Various exemplary embodiments will be described in detail below with reference to the drawings, in which the same or equivalent parts are designated by the same reference numerals.

[0026] First, a plasma processing apparatus, which is a substrate processing apparatus according to one exemplary embodiment, will be described with reference to FIGS.

[0027] FIG. 1 is a diagram illustrating an example of the configuration of a plasma processing system. In one embodiment, the plasma processing system includes a plasma processing apparatus 1 and a control unit 2. The plasma processing apparatus 1 includes a plasma processing chamber 10, a substrate support 11, and a plasma generation unit 12. The plasma processing chamber 10 has a plasma processing space. The plasma processing chamber 10 also has at least one gas supply port for supplying at least one processing gas to the plasma processing space and at least one gas exhaust port for exhausting gas from the plasma processing space. The gas supply port is connected to a gas supply unit 20 (described later), and the gas exhaust port is connected to an exhaust system 40 (described later). The substrate support 11 is disposed in the plasma processing space and has a substrate support surface for supporting a substrate.

[0028] The plasma generating unit 12 is configured to generate plasma from at least one processing gas supplied into the plasma processing space. The plasma formed in the plasma processing space may be capacitively coupled plasma (CCP), inductively coupled plasma (ICP), electron-cyclotron-resonance plasma (ECR plasma), helicon wave plasma (HWP), or surface wave plasma (SWP). Various types of plasma generating units may be used, including alternating current (AC) plasma generating units and direct current (DC) plasma generating units. In one embodiment, the AC signal (AC power) used in the AC plasma generating unit has a frequency in the range of 100 kHz to 10 GHz. Therefore, the AC signal includes a radio frequency (RF) signal and a microwave signal. In one embodiment, the RF signal has a frequency in the range of 100 kHz to 150 MHz.

[0029] 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).

[0030] The following describes a configuration example of a capacitively coupled plasma processing apparatus as an example of the plasma processing apparatus 1. Fig. 2 is a diagram for explaining a configuration example of a capacitively coupled plasma processing apparatus.

[0031] The capacitively coupled plasma processing apparatus 1 includes a plasma processing chamber 10, a gas supply 20, a power supply 30, and an exhaust system 40. The plasma processing apparatus 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 is grounded. The showerhead 13 and the substrate support 11 are electrically insulated from the housing of the plasma processing chamber 10.

[0032] 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.

[0033] In one embodiment, the main body 111 includes a base 1110 and an electrostatic chuck 1111. The base 1110 includes a conductive material such as aluminum. The conductive material of the base 1110 can function as a lower electrode. The electrostatic chuck 1111 is disposed on the base 1110.

[0034] The electrostatic chuck 1111 functions as a support plate for supporting the substrate W. The electrostatic chuck 1111 includes a ceramic body 1111a and an electrostatic electrode 1111b disposed within the body 1111a. The body 1111a has a central region 111a. In one embodiment, the body 1111a also has an annular region 111b. Note that the annular region 111b may also be provided by another member surrounding the electrostatic chuck 1111, such as the annular electrostatic chuck or an 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. At least one RF / DC electrode coupled to an RF power source 31 and / or a DC power source 32, which will be described later, may also be disposed within the body 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, which will be described later, is supplied to 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 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.

[0035] 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.

[0036] 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 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 main body 1111a of the electrostatic chuck 1111. The substrate support 11 may also include a heat transfer gas supply unit configured to supply a heat transfer gas to a gap between the backside of the substrate W and the central region 111a.

[0037] 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.

[0038] 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 at least one flow modulation device that modulates or pulses the flow rate of the at least one process gas.

[0039] 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 processing gas supplied to the plasma processing space 10s. Therefore, the RF power supply 31 can function as at least a part of the plasma generation unit 12. Furthermore, by supplying a bias RF signal to the at least one lower electrode, a bias potential is generated on the substrate W, and ion components in the formed plasma can be attracted to the substrate W.

[0040] 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.

[0041] 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.

[0042] 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 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.

[0043] In various embodiments, 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. 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.

[0044] 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.

[0045] 3 and 4 will be referred to below in addition to FIG. 2. Each of FIGS. 3 and 4 is a cross-sectional view showing a substrate support 11 according to an example embodiment. As described above, the substrate support 11 includes a base 1110 and an electrostatic chuck 1111. The electrostatic chuck 1111 is bonded onto the base 1110 via an adhesive layer 122. The adhesive layer 122 is made of an adhesive. The adhesive is, for example, an epoxy-based adhesive.

[0046] 3 and 4, the electrostatic chuck 1111 includes a substrate support surface 1111c and a ring support surface 1111d. The substrate support surface 1111c is the central region 111a described above. The electrostatic electrode 1111b of the electrostatic chuck 1111 is provided between the substrate support surface 1111c and the lower surface of the electrostatic chuck 1111. A DC power supply 114 is connected to the electrostatic electrode 1111b via a switch.

[0047] The main body 111 of the substrate support 11 is formed with gas supply holes 111g for supplying a heat transfer gas such as He gas between the substrate W and the upper surface of the electrostatic chuck 1111. The gas supply holes 111g are through-holes that penetrate the base 1110 in the thickness direction. A heat transfer gas supply unit 113 is connected to the gas supply holes 111g. The electrostatic chuck 1111 has a plurality of openings 111h that penetrate the electrostatic chuck 1111 in the thickness direction. At least one of the plurality of openings 111h is arranged in a position aligned with the gas supply hole 111g in the thickness direction of the base 1110 and communicates with the gas supply hole 111g. The opening 111h is a gas supply port that opens toward the gap between the substrate W and the upper surface of the electrostatic chuck 1111. The diameter of the opening 111h may be smaller than the diameter of the gas supply hole 111g.

[0048] The substrate support 11 further includes a sleeve 120. The sleeve 120 has, for example, a substantially cylindrical shape and covers an inner wall surface 1110s of the base 1110 that defines the gas supply holes 111g. The sleeve 120 is made of, for example, ceramic such as alumina. The sleeve 120 has a function of protecting the base 1110 from active species such as ions and radicals in the plasma. The sleeve 120 may be provided in a through hole 115h for inserting a lifter pin 115p, which will be described later.

[0049] The main body 111 of the substrate support 11 is further formed with a plurality of through holes 115h penetrating the main body 111 in the thickness direction. Some of the plurality of openings 111h of the electrostatic chuck 1111 are arranged at positions aligned with the plurality of through holes 115h and communicate with the plurality of through holes 115h. An inner wall surface 1110s of the base 1110, which defines the plurality of through holes 115h, is covered with a sleeve 120.

[0050] The plasma processing apparatus 1 may further include a support 115. The support 115 is movable up and down relative to the substrate support surface 1111c and is configured to be able to support the substrate W at a position spaced above the substrate support surface 1111c. The support 115 may include a plurality of lifter pins 115p. The plurality of lifter pins 115p are inserted into a plurality of through holes 115h formed in the main body 111. The plurality of lifter pins 115p are moved up and down along the plurality of through holes 115h by a drive unit 115d.

[0051] 4, when the tips of the plurality of lifter pins 115p are positioned above the substrate support surface 1111c, they come into contact with the substrate W. As a result, the support body 115 supports the substrate W at a position spaced above the substrate support surface 1111c.

[0052] FIG. 5 is a schematic cross-sectional view of the substrate support 11, enlarging the periphery of the gas supply hole 111g. As shown in FIG. 5, the substrate support 11 further includes a porous body 130 and an ionic liquid 140. The porous body 130 has a porous structure with numerous voids (pores) therein and is provided between the electrostatic chuck 1111 and the sleeve 120. That is, the adhesive layer 122 is not formed where the porous body 130 is disposed. The porous body 130 is made of a ceramic sintered body such as alumina (AL2O3), silica (SiO2), or silicon carbide (SiC). The porous body 130 may be a ceramic sprayed film formed by thermal spraying on the lower surface of the electrostatic chuck 1111. The porous body 130 may be bonded to the sleeve 120 by thermal spraying.

[0053] 5, the porous body 130 may include a first portion 130a and a second portion 130b provided to surround the first portion 130a. The first portion 130a extends in a substantially annular shape to surround the gas supply hole 111g, and a portion of the first portion 130a is exposed to the gas supply hole 111g. The second portion 130b is provided in a substantially annular shape between the first portion 130a and the adhesive layer 122. Typically, the outer peripheral surface of the second portion 130b is in contact with the adhesive layer 122.

[0054] The first portion 130a and the second portion 130b may have different bulk densities. For example, the bulk density of the second portion 130b is lower than the bulk density of the first portion 130a. In other words, the porosity of the second portion 130b is higher than the porosity of the first portion 130a.

[0055] The ionic liquid 140 is supported (held) within the pores of the porous body 130. The ionic liquid is an organic or inorganic salt composed of a cation and an anion. The ionic liquid 140 has low volatility and, for example, a saturated vapor pressure of 200 mTorr or less at 25°C. The ionic liquid 140 also has a higher thermal conductivity than helium gas. The ionic liquid 140 includes, for example, a pyrrolidinium salt, a pyridinium salt, an ammonium salt, or an imidazolium salt. In one embodiment, the amount of the ionic liquid 140 held in the second portion 130b of the porous body 130 may be greater than the amount of the ionic liquid 140 held in the first portion 130a.

[0056] If the sleeve 120 is bonded to the electrostatic chuck 1111 via an adhesive layer, part of the plasma generated in the plasma processing space 10s enters the gas supply holes 111g through the openings 111h formed in the electrostatic chuck 1111 during processing of the substrate W. This may result in the part of the adhesive layer exposed to the gas supply holes 111g being damaged by activated species of the plasma. Because the adhesive layer functions to transfer heat between the electrostatic chuck 1111 and the sleeve 120, if the adhesive layer is damaged, the electrostatic chuck 1111 and the sleeve 120 may partially become insulated by vacuum insulators in a reduced-pressure environment. As a result, the temperature of the electrostatic chuck 1111 may rise locally around the gas supply holes 111g. This may result in a decrease in the in-plane temperature uniformity of the substrate W supported on the electrostatic chuck 1111.

[0057] In contrast, in the above-described substrate support 11, a porous body 130 is disposed between the electrostatic chuck 1111 and the sleeve 120, and an ionic liquid 140 is held in the voids of the porous body 130. Since the electrostatic chuck 1111 and the sleeve 120 are in physical contact via the ionic liquid 140, heat can be conducted between the electrostatic chuck 1111 and the sleeve 120 via the ionic liquid 140. Heat transferred from the electrostatic chuck 1111 to the sleeve 120 is absorbed by the base 1110 and discharged to the outside of the substrate support 11 through heat exchange with a heat transfer fluid flowing through the flow path 1110a. Therefore, the substrate support 11 can suppress a decrease in the in-plane temperature uniformity of the electrostatic chuck 1111 and the substrate W supported thereon.

[0058] 5, the bulk density of the second portion 130b of the porous body 130 is lower than the bulk density of the first portion 130a of the porous body 130. Because the bulk density of the first portion 130a is relatively high, the first portion 130a can suppress the intrusion of activated species of the plasma between the electrostatic chuck 1111 and the sleeve 120. This can suppress wear of the adhesive layer 122. Furthermore, by making the bulk density of the second portion 130b relatively low, the amount of ionic liquid 140 held in the second portion 130b can be increased. This can improve heat transfer between the electrostatic chuck 1111 and the sleeve 120.

[0059] 5, the porous body 130 that holds the ionic liquid 140 is provided between the electrostatic chuck 1111 and the sleeve 120 in the gas supply hole 111g, but the porous body 130 may be provided between the electrostatic chuck 1111 and the sleeve 120 in the through hole 115h. Even in this case, a local increase in the temperature of the electrostatic chuck 1111 around the through hole 115h is suppressed, and therefore, a decrease in the in-plane temperature uniformity of the substrate W can be suppressed.

[0060] A method for manufacturing a substrate support 11 according to one example embodiment will be described below with reference to Fig. 6. The manufacturing method shown in Fig. 6 (hereinafter referred to as "manufacturing method MT") is performed to manufacture a substrate support 11 having an ionic liquid 140.

[0061] In the manufacturing method MT, first, a substrate support 11 is prepared (step ST1). As described above, the substrate support 11 includes a base 1110 having a gas supply hole 111g, an electrostatic chuck 1111 bonded to the base 1110 via an adhesive layer 122, a sleeve 120 provided in the gas supply hole 111g and covering an inner wall surface 1110s of the base 1110, and a porous body 130 disposed between the electrostatic chuck 1111 and the sleeve 120.

[0062] Next, the ionic liquid 140 is injected into the voids of the porous body 130 (step ST2). FIGS. 7(a) and 7(b) show an example of a method for injecting the ionic liquid 140 into the porous body 130. When injecting the ionic liquid 140 into the porous body 130, as shown in FIG. 7(a), the substrate support 11 is removed from the plasma processing apparatus 1, and the substrate support 11 is inverted so that the electrostatic chuck 1111 is positioned below the base 1110. At this time, the opening 111h of the electrostatic chuck 1111 is sealed using a sealing member 160 such as tape.

[0063] 7(b), the ionic liquid 140 is filled into the gas supply holes 111g from the opposite side of the electrostatic chuck 1111. As a result, the porous body 130 is immersed in the ionic liquid 140, and the ionic liquid 140 permeates into the pores of the porous body 130 by capillary action. As a result, a substrate support 11 in which the ionic liquid 140 is held in the pores of the porous body 130 can be manufactured.

[0064] The injection of the ionic liquid 140 described above is carried out every time the ionic liquid 140 held in the porous body 130 is consumed by the plasma treatment. By injecting the ionic liquid 140, the substrate support 11 from which the ionic liquid 140 has been consumed is regenerated.

[0065] The method of injecting the ionic liquid 140 into the porous body 130 is not limited to the methods shown in (a) and (b) of Figure 7. For example, a tube or a syringe may be inserted into the gas supply hole 111g, and the ionic liquid 140 may be injected into the porous body 130 through the tube or the syringe.

[0066] It should be noted that the steps of the manufacturing method MT may be performed simultaneously or in a different order, provided that there is no contradiction. The methods described in this disclosure present various steps in an exemplary order and are not limited to the particular order presented.

[0067] From the foregoing, it will be understood that various embodiments of the present disclosure have been described herein for purposes of illustration, and that various modifications may be made without departing from the scope and spirit of the present disclosure. Accordingly, the various embodiments disclosed herein are not intended to be limiting, with the true scope and spirit being indicated by the appended claims.

[0068] The present disclosure includes the following contents.

[0069] [1] A base having a through hole penetrating in its thickness direction; a support plate bonded to the base via an adhesive layer, the support plate having openings aligned with the through holes in the thickness direction; a sleeve covering an inner wall surface of the base that defines the through hole; a porous body disposed between the support plate and the sleeve; an ionic liquid held in the pores of the porous body; A substrate support comprising:

[0070] [2] The substrate support according to [1], wherein the ionic liquid has a saturated vapor pressure of 200 mTorr or less at 25°C.

[0071] [3] The substrate support according to [1] or [2], wherein the ionic liquid has a thermal conductivity higher than that of helium gas.

[0072] [4] The substrate support according to any one of [1] to [3], wherein the ionic liquid contains a pyrrolidinium salt, a pyridinium salt, an ammonium salt, or an imidazolium salt.

[0073] [5] The substrate support according to any one of [1] to [4], wherein the porous body is a ceramic body having a porous structure.

[0074] [6] The substrate support according to any one of [1] to [5], wherein the porous body is a thermally sprayed ceramic film.

[0075] [7] The porous body includes a first portion exposed to the through-hole and a second portion disposed between the first portion and the adhesive layer, The substrate support according to any one of [1] to [6], wherein the bulk density of the second portion is lower than the bulk density of the first portion.

[0076] [8] The substrate support according to [7], wherein the amount of the ionic liquid held in the second portion is greater than the amount of the ionic liquid held in the first portion.

[0077] [9] The substrate support according to any one of [1] to [8], wherein the support plate is an electrostatic chuck including a ceramic body and an electrostatic electrode provided within the body.

[0078]

[10] The substrate support according to any one of [1] to [9], further comprising a heat transfer gas supply unit configured to supply a heat transfer gas between the support plate and the substrate supported on the support plate through the through holes.

[0079]

[11] A chamber body; The substrate support according to any one of [1] to

[10] , which is disposed in the chamber body; A plasma processing apparatus comprising:

[0080]

[12] A process of preparing a substrate support, the substrate support comprising: a base having a through hole penetrating in a thickness direction thereof; a support plate bonded to the base via an adhesive layer, the support plate having an opening aligned with the through hole in the thickness direction; a sleeve covering an inner wall surface of the base that defines the through hole; and a porous body disposed between the support plate and the sleeve; injecting an ionic liquid into the pores of the porous body; A method for manufacturing a substrate support, comprising:

[0081]

[13] The step of injecting the ionic liquid includes: inverting the substrate support so that the support plate is positioned below the base; sealing the opening in the support plate; filling the through-holes of the inverted substrate support with the ionic liquid and allowing the ionic liquid to permeate into the voids of the porous body; The method for producing a semiconductor device according to

[12] , comprising: [Explanation of symbols]

[0082] 1...plasma processing apparatus, 11...substrate support, 1111a...main body, 1111b...electrostatic electrode, 111g...gas supply hole (through hole), 111h...opening, 115h...through hole, 120...sleeve, 122...adhesive layer, 130...porous body, 130a...first portion, 130b...second portion, 140...ionic liquid, 1110...base, 1110s...inner wall surface, 1111...electrostatic chuck, W...substrate.

Claims

1. a base having a through hole penetrating in its thickness direction; a support plate bonded to the base via an adhesive layer, the support plate having openings aligned with the through holes in the thickness direction; a sleeve covering an inner wall surface of the base that defines the through hole; a porous body disposed between the support plate and the sleeve; an ionic liquid held in the pores of the porous body; A substrate support comprising:

2. The substrate support of claim 1 , wherein the ionic liquid has a saturated vapor pressure of 200 mTorr or less at 25° C.

3. The substrate support of claim 1 , wherein the ionic liquid has a thermal conductivity higher than that of helium gas.

4. The substrate support of claim 1 , wherein the ionic liquid comprises a pyrrolidinium salt, a pyridinium salt, an ammonium salt, or an imidazolium salt.

5. 2. The substrate support according to claim 1, wherein the porous body is a ceramic body having a porous structure.

6. 2. The substrate support according to claim 1, wherein the porous body is a thermally sprayed ceramic film.

7. the porous body includes a first portion exposed to the through-hole and a second portion disposed between the first portion and the adhesive layer, The substrate support of claim 1 , wherein the bulk density of the second portion is lower than the bulk density of the first portion.

8. The substrate support according to claim 7 , wherein the amount of the ionic liquid held in the second portion is greater than the amount of the ionic liquid held in the first portion.

9. 2. The substrate support of claim 1, wherein the support plate is an electrostatic chuck including a ceramic body and an electrostatic electrode disposed within the body.

10. The substrate support of claim 1 , further comprising a heat transfer gas supply configured to supply a heat transfer gas between the support plate and a substrate supported on the support plate through the through holes.

11. a chamber body; a substrate support according to any one of claims 1 to 10, disposed within the chamber body; A plasma processing apparatus comprising:

12. a step of preparing a substrate support, the substrate support comprising: a base having a through hole penetrating in a thickness direction thereof; a support plate bonded to the base via an adhesive layer, the support plate having an opening aligned with the through hole in the thickness direction; a sleeve covering an inner wall surface of the base that defines the through hole; and a porous body disposed between the support plate and the sleeve; injecting an ionic liquid into the pores of the porous body; A method for manufacturing a substrate support, comprising:

13. The step of injecting the ionic liquid includes: inverting the substrate support so that the support plate is positioned below the base; sealing the opening in the support plate; filling the through-holes of the inverted substrate support with the ionic liquid and allowing the ionic liquid to permeate into the voids of the porous body; The method of claim 12, comprising:

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