Substrate support, substrate processing apparatus, and method for manufacturing a substrate support

Abstract

The present invention provides a substrate support that can appropriately regulate the temperature of the substrate by using a heat transfer medium that flows through a channel formed in the base. [Solution] A substrate support comprising: a substrate support portion made of a first material, having electrodes provided inside and configured to support the substrate; a base made of a second material different from the first material, having a flow channel configured to allow the circulation of a temperature-controlling fluid for the substrate; and a diffusion junction portion formed in the boundary region between the substrate support portion and the base. The difference between the linear expansion coefficient of the first material and the linear expansion coefficient of the second material is 1.0 × 10⁻⁶. -6 The temperature is below / ℃, and the first material includes silicon carbide-containing ceramics.

Description

[Technical Field]

[0001] This disclosure relates to a substrate support, a substrate processing apparatus, and a method for manufacturing a substrate support. [Background technology]

[0002] Patent Document 1 discloses a substrate processing apparatus comprising a base in which a coolant flow path extending to an inlet and an outlet is provided inside, and a mounting table having an electrostatic chuck provided on the upper surface of the base via adhesive, with a heater provided inside or on the lower surface. [Prior art documents] [Patent Documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2013-172013 [Overview of the Initiative] [Problems that the invention aims to solve]

[0004] The technology disclosed herein provides a substrate support capable of appropriately regulating the temperature of a substrate by using a heat transfer medium that flows through a channel formed in the base. [Means for solving the problem]

[0005] One aspect of the present disclosure is a substrate support having electrodes provided inside and supporting a substrate, comprising: a substrate support portion made of a first material configured to support the substrate; a base made of a second material different from the first material and having a flow channel configured to allow the circulation of a temperature-controlling fluid for the substrate; and a diffusion junction formed in the boundary region between the substrate support portion and the base, wherein the difference between the linear expansion coefficient of the first material and the linear expansion coefficient of the second material is 1.0 × 10⁻⁶. -6 The temperature is below / ℃, and the first material includes silicon carbide-containing ceramics. [Effects of the Invention]

[0006] According to this disclosure, a substrate support can be provided that can appropriately regulate the substrate temperature by a heat transfer fluid flowing through a channel formed in the base. [Brief explanation of the drawing]

[0007] [Figure 1] Figure 1 is a longitudinal cross-sectional view showing an example of the configuration of a plasma processing system according to this embodiment. [Figure 2] Figure 2 is a longitudinal cross-sectional view showing an example of the configuration of the substrate support according to this embodiment. [Figure 3] Figure 3 is a schematic cross-sectional view showing an example of a conventional substrate support configuration. [Figure 4] Figure 4 is a longitudinal cross-sectional view showing an example of the configuration of a substrate support according to Modification 1 of this embodiment. [Figure 5] Figure 5 is a plan view showing an example of the configuration of a substrate support according to Modification 1 of this embodiment. [Figure 6] Figure 6 is a longitudinal cross-sectional view showing an example of the configuration of a substrate support according to a modified example 2 of this embodiment. [Figure 7] Figure 7 is a flowchart of substrate processing using a substrate processing measure including a substrate support according to Modification 2 of this embodiment. [Modes for carrying out the invention]

[0008] In the manufacturing process of semiconductor devices, etching is performed on an etching target layer (e.g., a silicon-containing film) formed by laminating on the surface of a semiconductor substrate (hereinafter simply referred to as "substrate"), using a mask layer (e.g., a resist film) with a pre-formed pattern as a mask. This etching process is generally carried out in a plasma processing apparatus equipped with a substrate support that uses electrostatic force to adsorb and hold the substrate.

[0009] Patent Document 1 discloses a substrate processing apparatus equipped with such a substrate support (mounting stage). The substrate support described in Patent Document 1 is formed by joining a base with a flow path for a coolant and an electrostatic chuck equipped with a heater for heating the substrate via an adhesive.

[0010] By the way, in recent plasma processing apparatuses, as the above-described etching process, a 3D NAND HARC (High Aspect Ratio Contact) process (hereinafter simply referred to as the "HARC process") of deeply digging holes in a substrate formed by stacking may be performed. However, in the HARC process, while there is a requirement to appropriately form deep holes by increasing the RF (Radio Frequency) power, there is a risk that the holes cannot be appropriately formed due to the increase in the temperature of the substrate caused by the increase in RF power. Specifically, due to the increase in the temperature of the substrate, the opening of the hole formed on the substrate may be blocked, and thus there is a risk that the hole cannot be appropriately dug deep.

[0011] Here, as a countermeasure method for suppressing the blockage of the hole and appropriately performing the HARC process, for example, keeping the substrate to be processed below a desired temperature, that is, appropriately cooling the substrate can be considered.

[0012] The cooling of the substrate supported by the substrate support is generally performed by a refrigerant flowing through a flow path formed inside the base of the substrate support, as disclosed in Patent Document 1. However, when a base having a flow path and an electrostatic chuck for supporting the substrate, like the substrate support (mounting table) disclosed in Patent Document 1, are joined via an adhesive containing a resin material (hereinafter referred to as a "resin adhesive"), the cooling of the substrate may not be appropriately performed. This is because the thermal resistance of the resin adhesive is greater than the thermal resistance of the electrostatic chuck or the base, and the heat transfer from the refrigerant to the substrate is inhibited by the resin adhesive. Therefore, from such a viewpoint, there is room for improvement in the conventional substrate support, and the development of a substrate support capable of achieving both an increase in RF power and a decrease in the temperature of the substrate is required.

[0013] The technology according to the present disclosure has been made in view of the above circumstances, and provides a substrate support that can appropriately cool a substrate by a heat transfer fluid flowing through a flow path formed in a base. Hereinafter, a plasma processing system as a substrate processing apparatus according to the present embodiment will be described with reference to the drawings. In the present specification and drawings, elements having substantially the same functional configuration are denoted by the same reference numerals, and redundant description is omitted.

[0014] <Plasma Processing Apparatus> First, the plasma processing system according to the present embodiment will be described. FIG. 1 is a longitudinal sectional view showing an outline of the configuration of the plasma processing system according to the present embodiment.

[0015] The plasma processing system includes a capacitively coupled plasma processing apparatus 1 and a control unit 2. The plasma processing apparatus 1 includes a plasma processing chamber 10, a gas supply unit 20, a power source 30, and an exhaust system 40. The plasma processing apparatus 1 also includes a substrate support 11 and a gas introduction unit. The substrate support 11 is disposed inside the plasma processing chamber 10. The gas introduction unit is configured to introduce at least one processing gas into the plasma processing chamber 10. The gas introduction unit includes a shower head 13. The shower head 13 is disposed above the substrate support 11. In one embodiment, the shower head 13 constitutes at least a part of the ceiling of the plasma processing chamber 10. Inside the plasma processing chamber 10, a plasma processing space 10s defined by the shower head 13, the side wall 10a of the plasma processing chamber 10, and the substrate support 11 is formed. The plasma processing chamber 10 has at least one gas supply port 13a for supplying at least one processing gas to the plasma processing space 10s and at least one gas discharge port 10e for discharging gas from the plasma processing space 10s. The side wall 10a is grounded. The shower head 13 and the substrate support 11 are electrically insulated from the plasma processing chamber 10.

[0016] The substrate support 11 includes a main body member 111 and a ring assembly 112. The upper surface of the main body member 111 has a central region 111a (substrate support surface) for supporting the substrate (wafer) W and an annular region 111b (ring support surface) for supporting the ring assembly 112. The annular region 111b surrounds the central region 111a in plan view. The ring assembly 112 includes one or more annular members, at least one of which is an edge ring.

[0017] As shown in Figure 2, in one embodiment, the main body member 111 includes a base 113 and an electrostatic chuck 114. The electrostatic chuck 114 is an example of a substrate support part that supports a substrate. The base 113 and the electrostatic chuck 114 are diffusion bonded. When the base 113 and the electrostatic chuck 114 are diffusion bonded, a diffusion bond portion 115 is formed in the boundary region between the base 113 and the electrostatic chuck 114.

[0018] The base 113 is made of a conductive material such as titanium (Ti), as will be described later. The base 113 functions as a lower electrode. The base 113 has a flow path C through which a heat transfer medium (temperature control fluid) from a chiller unit (not shown) is circulated and supplied. By circulating the heat transfer medium in the flow path C, the ring assembly 112, the electrostatic chuck 114 (described later), and the substrate W are adjusted to the desired temperature. As an example, a refrigerant such as cooling water can be used as the heat transfer medium.

[0019] In Figure 2, the channel C is formed in the lower part of the central region 111a (substrate W) of the base 113, but the channel C may also be further formed in the lower part of the annular region 111b, corresponding to the ring assembly 112.

[0020] The electrostatic chuck 114 is diffusion-bonded to the upper surface of the base 113. The upper surface of the electrostatic chuck 114 has the aforementioned central region 111a and annular region 111b. Inside the electrostatic chuck 114, there is a first electrode 114a for adsorbing and holding the substrate W and a second electrode 114b for adsorbing and holding the ring assembly 112. The electrostatic chuck 114 is constructed by sandwiching the first electrode 114a and the second electrode 114b between a pair of dielectric films made of a dielectric material such as ceramics.

[0021] In Figure 2, an example is shown where the central region 111a that holds the substrate W on its upper surface and the annular region 111b that holds the ring assembly 112 on its upper surface are integrally configured in the electrostatic chuck 114. However, the configuration of the electrostatic chuck 114 is not limited to this, and the central region 111a and the annular region 111b of the electrostatic chuck 114 may be configured independently. By configuring the central region 111a and the annular region 111b independently in this way, the temperature control of the substrate W and the temperature control of the ring assembly 112 can be performed thermally separated and independently.

[0022] Although not shown in the figures, the substrate support 11 may further include a heating module such as a heater for heating at least one of the ring assembly 112, the electrostatic chuck 114, and the substrate W. The heater as a heating module may be provided, for example, inside the electrostatic chuck 114, below the first electrode 114a and / or the second electrode 114b. The substrate support 11 may also include a heat transfer gas supply unit configured to supply heat transfer gas (backside gas) between the back surface of the substrate W and the upper surface of the electrostatic chuck 114.

[0023] The shower head 13 is configured to introduce at least one processing gas from the gas supply unit 20 into the plasma processing space 10s. The shower head 13 has at least one gas supply port 13a, at least one gas diffusion chamber 13b, and a plurality of gas inlet ports 13c. The processing gas supplied from the gas supply unit 20 to the gas supply port 13a passes through the gas diffusion chamber 13b and is introduced into the plasma processing space 10s through the plurality of gas inlet ports 13c. The shower head 13 also includes a conductive member. The conductive member of the shower head 13 functions as an upper electrode. In addition to the shower head 13, the gas introduction unit may also include one or more side gas injectors (SGIs) attached to one or more openings formed in the side wall 10a.

[0024] 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 processing gas to the shower head 13 from a corresponding gas source 21 via a corresponding flow controller 22. Each flow controller 22 may include, for example, a mass flow controller or a pressure-controlled flow controller. Furthermore, the gas supply unit 20 may include one or more flow modulation devices that modulate or pulse the flow rate of at least one processing gas.

[0025] 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), such as a source RF signal and a bias RF signal, to a conductive member (lower electrode) of the substrate support 11 and / or a conductive member (upper electrode) of the showerhead 13. This causes plasma to be formed from at least one processing gas supplied to the plasma processing space 10s. Thus, the RF power supply 31 can function as at least part of a plasma generation unit configured to generate plasma from one or more processing gases in the plasma processing chamber 10. Furthermore, by supplying a bias RF signal to the lower electrode, a bias potential is generated on the substrate W, and ionic components in the formed plasma can be drawn into the substrate W.

[0026] In one embodiment, the RF power supply 31 includes a first RF generation unit 31a and a second RF generation unit 31b. The first RF generation unit 31a is coupled to the lower electrode and / or 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 13 MHz to 150 MHz. In one embodiment, the first RF generation unit 31a may be configured to generate a plurality of source RF signals having different frequencies. One or more generated source RF signals are supplied to the lower electrode and / or upper electrode. The second RF generation unit 31b is coupled to the lower electrode via at least one impedance matching circuit and is configured to generate a bias RF signal (bias RF power). In one embodiment, the bias RF signal has a lower frequency than the source RF signal. In one embodiment, the bias RF signal has a frequency in the range of 400 kHz to 13.56 MHz. In one embodiment, the second RF generation unit 31b may be configured to generate a plurality of bias RF signals having different frequencies. The generated bias RF signals are supplied to the lower electrode. In various embodiments, at least one of the source RF signal and the bias RF signal may also be pulsed.

[0027] Furthermore, the power supply 30 may include a DC power supply 32 coupled to the plasma processing chamber 10. The DC power supply 32 includes a first DC generation unit 32a and a second DC generation unit 32b. In one embodiment, the first DC generation unit 32a is connected to the lower electrode and configured to generate a first DC signal. The generated first bias DC signal is applied to the lower electrode. In one embodiment, the first DC signal may be applied to another electrode, such as an adsorption electrode in the electrostatic chuck 114. In one embodiment, the second DC generation unit 32b is connected to the upper electrode and configured to generate a second DC signal. The generated second DC signal is applied to the upper electrode. In various embodiments, at least one of the first and second DC signals may be pulsed. Note that the first and second DC generation units 32a and 32b may be provided in addition to the RF power supply 31, and the first DC generation unit 32a may be provided in place of the second RF generation unit 31b.

[0028] The exhaust system 40 may be connected to, for example, a gas outlet 10e located 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 internal pressure of the plasma processing space 10s. The vacuum pump may include a turbomolecular pump, a dry pump, or a combination thereof.

[0029] The control unit 2 processes computer-executable instructions that cause the plasma processing apparatus 1 to perform the various processes described herein. The control unit 2 may be configured to control each element of the plasma processing apparatus 1 to perform the 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, for example, a computer 2a. The computer 2a may include, for example, a processing unit (CPU: Central Processing Unit) 2a1, a storage unit 2a2, and a communication interface 2a3. The processing unit 2a1 may be configured to perform various control operations based on a program stored in the storage unit 2a2. The storage unit 2a2 may include RAM (Random Access Memory), ROM (Read Only Memory), HDD (Hard Disk Drive), SSD (Solid State Drive), or a combination thereof. The communication interface 2a3 may communicate with the plasma processing apparatus 1 via a communication line such as a LAN (Local Area Network).

[0030] Although various exemplary embodiments have been described above, the invention is not limited to the exemplary embodiments described above, and various additions, omissions, substitutions, and modifications may be made. Furthermore, it is possible to combine elements from different embodiments to form other embodiments.

[0031] <Method for processing substrates using plasma processing equipment> Next, an example of a method for processing the substrate W in the plasma processing apparatus 1 configured as described above will be explained. In the plasma processing apparatus 1, an etching process (for example, a HARC process) is performed on the substrate W.

[0032] First, the substrate W is brought into the plasma processing chamber 10 and placed on the electrostatic chuck 114 of the substrate support 11. Next, a voltage is applied to the adsorption electrode of the electrostatic chuck 114, and the substrate W is held in place by electrostatic force.

[0033] Once the substrate W is held by the electrostatic chuck 114, the inside of the plasma processing chamber 10 is then depressurized to a predetermined vacuum. Next, processing gas is supplied from the gas supply unit 20 to the plasma processing space 10s via the shower head 13. Source RF power for plasma generation is supplied from the first RF generation unit 31a to the lower electrode, thereby exciting the processing gas and generating plasma. At this time, bias RF power may also be supplied from the second RF generation unit 31b. Then, in the plasma processing space 10s, the substrate W is etched by the action of the generated plasma.

[0034] When the etching process is completed, the supply of source RF power from the first RF generation unit 31a and the supply of processing gas from the gas supply unit 20 are stopped. If bias RF power was being supplied during the etching process, the supply of said bias RF power is also stopped.

[0035] Next, the electrostatic chuck 114 stops holding the substrate W, and the substrate W and the electrostatic chuck 114 are destaticized after the etching process. After that, the substrate W is detached from the electrostatic chuck 114 and removed from the plasma processing apparatus 1. This completes the series of etching processes.

[0036] <Method for cooling a substrate supported by a substrate support> Figure 3 is a schematic cross-sectional view showing an example of the configuration of a conventional substrate support 200, which is provided in a substrate processing apparatus, for example, disclosed in Patent Document 1. In the following description, elements having the same configuration as the substrate support 11 in the present disclosure are denoted by the same reference numerals, and detailed explanations are omitted.

[0037] As shown in Figure 3, the conventional substrate support 200 includes an electrostatic chuck 114 and a base 201. The electrostatic chuck 114 and the base 201 are laminated and joined together via an adhesive 202.

[0038] The electrostatic chuck 114 has a configuration similar to the electrostatic chuck 114 used for the substrate support 11. That is, it is constructed by sandwiching an adsorption electrode between insulating materials, such as ceramics. The substrate W and the ring assembly 112 are adsorbed and held on the upper surface of the electrostatic chuck 114.

[0039] The base 201 is made of a conductive material such as an Al alloy. The base 201 functions as a lower electrode. A channel C is formed in the base 201.

[0040] The adhesive 202 joins the electrostatic chuck 114 and the base 201. As described above, the adhesive 202 generally has a higher thermal resistance (lower thermal conductivity) than the electrostatic chuck 114 and the base 201. For this reason, when the substrate W is supported by the conventional substrate support 200 and an etching process (e.g., HARC process) is performed, there is a risk that holes cannot be properly formed in depth in the substrate W. In other words, as described above, when RF is applied at high power to the lower electrode, the substrate W held by the electrostatic chuck 114 becomes hot, which may cause the hole openings to become blocked and prevent etching from proceeding.

[0041] One possible method to suppress blockage of the hole opening is to cool the substrate W held by the electrostatic chuck 114 by heat transfer from the coolant flowing through the channel C formed in the base 201. However, as with conventional substrate supports 200, if the base 201 with the channel C and the electrostatic chuck 114 that adsorbs and holds the substrate W are joined by a resin adhesive with high thermal resistance (thermal conductivity: 0.2~0.3 W / mK), the heat transfer from the coolant to the substrate W may be hindered by the resin adhesive, potentially preventing proper cooling of the substrate W.

[0042] Therefore, in the substrate support 11 according to this embodiment, as shown in Figure 2, the base 113 with a flow channel C formed therein and the electrostatic chuck 114 are joined by diffusion bonding. As a result, heat transfer from the refrigerant flowing through the flow channel C to the electrostatic chuck 114 (substrate W) is promoted compared to the conventional method, so that the substrate W can be cooled appropriately. In other words, it becomes possible to achieve both high power RF applied to the lower electrode and low temperature of the substrate W.

[0043] In this embodiment, when the base 113 and the electrostatic chuck 114 are diffusion-bonded, the upper surface of the base 113 and the bottom surface of the electrostatic chuck 114 are in contact with each other, and these components are pressurized in a high-temperature environment. At this time, if the difference in the coefficients of linear expansion between the base 113 and the electrostatic chuck 114 is large, residual stress caused by thermal stress generated during bonding may cause damage or warping to the base 113 or the electrostatic chuck 114.

[0044] For example, as shown in Figure 3, the conventional substrate support 200 is made of aluminum alloy (coefficient of linear expansion: approximately 23 × 10⁻⁶). -6 Base 201 made of (°C) and ceramics (coefficient of linear expansion: approximately 7 × 10) -6 ~8×10 -6 When the electrostatic chuck 114 made of ( / °C) is diffusion bonded, the thermal expansion of the base 201 is greater than that of the electrostatic chuck 114. As a result, residual stress generated when cooled to room temperature can cause damage or warping of the base 113 or the electrostatic chuck 114.

[0045] Therefore, in this embodiment, the difference in the coefficient of thermal expansion between the first material constituting the electrostatic chuck 114 and the second material constituting the base is set to 1.0 × 10⁻⁶. -6 The temperature should be below / ℃. For example, the first material may be a ceramic such as alumina containing SiC (coefficient of linear expansion: approximately 7.8 × 10⁻⁶). -6 Using (°C / °C), and as the second material, titanium or titanium alloy (coefficient of linear expansion: approximately 8.4 × 10⁻⁶) -6Use (in units of / °C). Thus, by reducing the difference in the linear expansion coefficients between the electrostatic chuck 114 and the base 113 joined by the diffusion bonding portion 115, the thermal stress generated during the joining of the electrostatic chuck 114 and the base 113 can be reduced. That is, the residual stress generated between the electrostatic chuck 114 and the base 113 can be reduced, thereby appropriately suppressing breakage or warping of the base 113 and the electrostatic chuck 114 due to the difference in the linear expansion coefficients. Note that the linear expansion coefficient described above means the linear expansion coefficient at room temperature.

[0046] As described above, the diffusion bonding portion 115 is formed in the boundary region between the base 113 and the electrostatic chuck 114. For example, when the base 113 and the electrostatic chuck 114 are diffusion bonded with the upper surface of the base 113 and the bottom surface of the electrostatic chuck 114 in contact, the diffusion bonding portion 115 is composed of a first material and a second material. More specifically, in the boundary region between the electrostatic chuck 114 and the base 113, grain boundary migration has occurred, and the crystal grains of the first material and the crystal grains of the second material are in a mixed state. In this embodiment, the base 113 and the electrostatic chuck 114 may be diffusion bonded via a third material different from the first material and the second material. That is, the base 113 and the electrostatic chuck 114 may be diffusion bonded with a third material such as an insert metal that can diffuse into the first material and the second material sandwiched between the upper surface of the base 113 and the bottom surface of the electrostatic chuck 114. In this case, the diffusion bonding portion 115 is composed of the first material, the second material, and the third material.

[0047] In this embodiment, the second material constituting the base 113 is not limited to titanium or a titanium alloy as shown in this embodiment, and can be arbitrarily selected as long as it is a conductive member having a difference in the linear expansion coefficient from the electrostatic chuck 114 of 1.0×10 -6 / °C or less. Specifically, as a result of intensive studies by the inventors, if the linear expansion coefficient of the second material constituting the base 113 is about 7 to 9×10 -6 / °C, breakage or warping of the base 113 and the electrostatic chuck 114 due to the difference in the linear expansion coefficient can be appropriately suppressed. The difference in the linear expansion coefficient from the ceramics is 1.0×10-6 Other conductive materials that exhibit temperatures below / ℃ include, for example, low thermal expansion iron-nickel alloys.

[0048] In this embodiment, the substrate support 11 can be manufactured, for example, by pressing the components in a high-temperature environment while the bottom surface of the electrostatic chuck 114 and the top surface of the base 113 are in contact. A hot press can be used as a means of applying pressure in a high-temperature environment. In this case, as described above, the difference in the coefficient of linear expansion between the first material constituting the electrostatic chuck 114 and the second material constituting the base 113 is 1.0 × 10⁻⁶. -6 Even at temperatures below / °C, thermal stress generated during bonding may cause damage to the electrostatic chuck 114 and base 113. Generally, the coefficient of linear expansion is temperature-dependent, so if materials with a large difference in their coefficients of linear expansion are used as the first and second materials in the temperature range where diffusion bonding is performed, the electrostatic chuck 114 and base 113 are more prone to breakage and warping.

[0049] Therefore, in this embodiment, in order to suppress damage to the electrostatic chuck 114 and base 113 caused by thermal stress generated during such bonding, it is desirable to increase the pressure during diffusion bonding and lower the bonding temperature. Conventionally, diffusion bonding of titanium or titanium alloys is generally performed under conditions of 0.6 MPa to 2 MPa and 850°C to 930°C. In contrast, in this embodiment, it is desirable to perform the bonding under conditions of, for example, 2 MPa or more and 500°C or less. By performing diffusion bonding under such conditions, the difference in the amount of thermal expansion generated during bonding can be reduced, and damage and warping of the electrostatic chuck 114 can be suppressed, and the base 113 and the electrostatic chuck 114 can be properly bonded.

[0050] <Example 1> As described above, in the substrate support 11 according to this embodiment, the difference in the coefficient of linear expansion between the first material constituting the electrostatic chuck 114 and the second material constituting the base 113 is 1.0 × 10⁻⁶ -6By keeping the temperature below / °C, warping and damage to the electrostatic chuck 114 caused by the difference in the coefficient of thermal expansion between the first material and the second material are suppressed. However, if residual stress generated during manufacturing cannot be sufficiently reduced, warping and damage may occur to the electrostatic chuck 114 and base 113. Also, in processes that repeatedly alternate between low-temperature and high-temperature processes on the substrate W, strain may accumulate in the electrostatic chuck 114 and base 113, and similarly, warping and damage may occur to the electrostatic chuck 114 and base 113.

[0051] In contrast, in Modification 1 shown in Figure 4, multiple grooves 116 are formed on the joining surface of the base 113 (the surface facing the back surface of the electrostatic chuck 114). Figure 5 is a plan view of the base 113 of Modification 1. As shown in Figure 5(a), the grooves 116 may be formed in a concentric circle shape. In this case, each groove 116 may be divided into multiple parts in the circumferential direction. Figure 5(b) shows an example in which the groove 116 is divided into four parts in the circumferential direction, and Figure 5(c) shows an example in which the groove 116 is divided into eight parts in the circumferential direction. In addition, the grooves 116 may be formed in a spiral shape. With such a configuration, residual stress generated during manufacturing or substrate processing can be relieved by the deformation of the grooves 116. Therefore, it is possible to further suppress warping and damage of the electrostatic chuck 114 or the base 113.

[0052] <Modification 2> A modified example 2 of the substrate support 11 according to this embodiment, shown in Figure 6, is the modified example 1 shown in Figure 4, with the addition of a heat transfer gas control system 117 for supplying heat transfer gas into the groove 116 and controlling the pressure of the heat transfer gas. An inert gas such as helium (He) can be used as the heat transfer gas. The heat transfer gas control system 117 may include a heat transfer gas supply source 117a, a gas line 117b connecting the groove 116 and the heat transfer gas supply source 117a, a pressure control device 117c for controlling the pressure of the heat transfer gas supplied to the groove 116, a pump 117d for reducing the pressure in the groove 116, and a recovery tank 117e for recovering the heat transfer gas supplied to the groove 116. The heat transfer gas control system 117 may also be equipped with valves V1 to V5 at various points in the gas line. In this configuration, the amount of heat transferred from the substrate W to the refrigerant during substrate processing can be changed by changing the pressure of the heat transfer gas in the groove 116. As a result, for example, in processes where high-temperature and low-temperature processes are repeatedly performed on the substrate W, the time required for temperature changes can be shortened, thereby improving productivity. In the modified example shown in Figure 6, a temperature sensor 118 for measuring the temperature of the electrostatic chuck 114 may be provided. A radiation thermometer or the like can be used as the temperature sensor 118.

[0053] Figure 7 shows an example of a substrate processing flow using the substrate support 11 according to Modification 2. Figure 7 is an example of a flow when performing etching at a low temperature (first etching) and etching at a high temperature (second etching, third etching) on ​​the substrate W. Note that in the initial state, valves V1 to V5 are closed.

[0054] In ST1, valve V3 is opened and the pressure inside the groove 116 is reduced by pump 117d. For example, a dry pump can be used as pump 117d. Subsequently, in ST2, valve V1 is opened and the pressure inside the groove 116 is measured by pressure control device 117c. Then, in ST3, valve V3 is closed and valve V2 is opened and heat transfer gas is supplied into the groove 116 from heat transfer gas supply source 117a via gas line 117b. In ST4, when the pressure inside the groove 116 reaches a predetermined pressure, valve V3 is closed and the temperature of the electrostatic chuck 114 is measured by temperature sensor 118. In ST5, after the electrostatic chuck 114 reaches a predetermined temperature, the first etching is started. In one example, the pressure inside the groove 116 during the first etching is set to 30 Torr. This promotes heat transfer from the substrate W to the coolant.

[0055] After the first etching is complete, in ST6, valve V1 is closed and valve V4 is opened to reduce the pressure inside the recovery tank 117e. In one example, the recovery tank 117e is reduced to a vacuum. In ST7, valves V5 and V1 are opened to recover the heat transfer gas in the groove 116 into the recovery tank 117e. In ST8, valve V5 is closed and valve V3 is opened, and the pressure inside the groove 116 is reduced by pump 117d. In ST9, after confirming that the pressure inside the groove 116 has reached a predetermined level using the pressure control device 117c, the second etching is started. In one example, the pressure inside the groove 116 during the second etching is set to 0-10 Torr. This suppresses heat transfer from the substrate W to the coolant. Thereafter, ST1-ST9 are repeated until a predetermined number of substrates W have been etched, at which point the process is terminated.

[0056] In the modified example 2, the time required for the temperature change of the substrate W during substrate processing can be shortened by controlling the pressure of the heat transfer gas in the groove 116. In addition, since the heat transfer gas can be recovered and reused, cost improvement and resource conservation are possible.

[0057] <Effects of the substrate support according to this disclosure> As described above, according to the substrate support 11 of this embodiment, the base 113 on which the flow path C is formed and the electrostatic chuck 114 that adsorbs and holds the substrate W are diffusely bonded together.

[0058] As a result, heat is properly transferred from the refrigerant to the substrate W, allowing for proper cooling of the substrate W. Therefore, even when performing the HARC process, the substrate W can be properly cooled. In other words, the substrate support 11 according to this embodiment makes it possible to achieve both high RF power and low substrate W temperature, and to properly form deep holes in the substrate W.

[0059] Furthermore, according to this embodiment, the difference in the coefficient of linear expansion between the first material constituting the electrostatic chuck 114 and the second material constituting the base 113 is 1.0 × 10⁻⁶. -6 The temperature should be below / °C. This suppresses damage or cracking of the electrostatic chuck 114 caused by the difference in the coefficient of thermal expansion between the base 113 and the electrostatic chuck 114 when the base 113 and the electrostatic chuck 114 are diffusion bonded. Furthermore, even when RF is applied at high power during the HARC process and the base 113 and electrostatic chuck 114 become hot, the residual stress generated between the base 113 and the electrostatic chuck 114 can be reduced. As a result of reducing the residual stress generated in this way, damage or warping caused by the difference in the coefficient of thermal expansion between the base 113 and the electrostatic chuck 114 during the HARC process is appropriately suppressed.

[0060] Furthermore, according to the substrate support 11 of this embodiment, the thermal responsiveness of the substrate support 11 and the substrate W during etching is improved by diffusion bonding the base 113 and the electrostatic chuck 114. That is, for example, in processes where RF is applied alternately with high power and low power during etching, thermal tracking can be improved, making it possible to repeatedly switch the RF power in a shorter amount of time.

[0061] Furthermore, according to the substrate support 11 of the modified example 1, residual stress generated during manufacturing or substrate processing can be relieved by the deformation of the groove 116, thereby further suppressing warping and damage to the electrostatic chuck 114 or base 113.

[0062] Furthermore, according to the substrate support of Modified Example 2, the time required for temperature change of the substrate W during substrate processing can be shortened by controlling the pressure of the heat transfer gas in the groove 116. In addition, since the heat transfer gas can be recovered and reused, cost improvement and resource conservation are possible.

[0063] The embodiments disclosed herein should be considered in all respects to be illustrative and not restrictive. The above embodiments may be omitted, replaced, or modified in various ways without departing from the scope and spirit of the appended claims.

[0064] The embodiments disclosed above include, for example, the following aspects:

[0065] [Note 1] A substrate support part made of a first material, configured to support the substrate, A base made of a second material different from the first material has a flow path configured to allow the temperature-controlling fluid of the substrate to flow through, A diffusion bonding portion formed in the boundary region between the substrate support portion and the base, Equipped with, The difference between the coefficient of thermal expansion of the first material and the coefficient of thermal expansion of the second material is 1.0 × 10⁻⁶. -6 It is below / ℃. Substrate support.

[0066] [Note 2] The diffusion junction portion is a substrate support according to Appendix 1, comprising the first material and the second material.

[0067] [Note 3] The substrate support according to Appendix 2, wherein the diffusion junction further comprises a third material different from the first and second materials.

[0068] [Note 4] The first material is a substrate support according to any one of the appendices 1 to 3, comprising silicon carbide-containing ceramics.

[0069] [Note 5] The second material has a coefficient of thermal expansion of 7.0 × 10 -6 / ℃~9.0×10 -6 A substrate support as described in any of Appendix 1 to Appendix 4, wherein the temperature is / ℃.

[0070] [Note 6] The substrate support according to any one of the appendices 1 to 5, wherein the second material is titanium or a titanium alloy.

[0071] [Note 7] The substrate support according to any one of the appendices 1 to 6, wherein the base has a plurality of grooves arranged concentrically on the surface facing the substrate support portion.

[0072] [Note 8] The substrate support according to Appendix 7, wherein the plurality of grooves each have a plurality of regions divided in the circumferential direction.

[0073] [Note 9] The system further comprises a heat transfer gas control system for supplying heat transfer gas into the plurality of grooves and controlling the pressure of the heat transfer gas, The heat transfer gas control system is Heat transfer gas supply source, A gas line connecting the plurality of grooves and the heat transfer gas supply source. A pressure control device for controlling the pressure of the heat transfer gas supplied to the plurality of grooves, A pump for reducing pressure in the aforementioned multiple grooves, A recovery tank for recovering the heat transfer gas supplied to the plurality of grooves, including, A substrate support as described in either Appendix 7 or Appendix 8.

[0074] [Note 10] A step of bringing into contact the bottom surface of a substrate support made of a first material, which is configured to support the substrate, and the top surface of a base made of a second material different from the first material, which has a flow path configured to allow a temperature-controlling fluid for the substrate to flow through it. A step of diffusion bonding the substrate support portion and the base to form a diffusion bond portion in the boundary region between the substrate support portion and the base, Equipped with, The difference between the coefficient of thermal expansion of the first material and the coefficient of thermal expansion of the second material is 1.0 × 10⁻⁶. -6 It is below / ℃. A method for manufacturing a substrate support.

[0075] [Note 11] The method for manufacturing a substrate support according to Appendix 10, wherein the step of forming the diffusion junction is to form the diffusion junction by hot pressing the substrate support and the base.

[0076] [Note 12] The method for manufacturing a substrate support as described in Appendix 11, wherein the hot pressing is performed at a temperature of 2 MPa or higher and 500°C or lower.

[0077] [Note 13] Chamber and, A substrate support according to any one of appendices 1 to 9, which is disposed within the chamber, A substrate processing apparatus, including

[0078] This application claims priority to U.S. Provisional Application 63 / 141,597, filed with the U.S. Patent and Trademark Office on 26 January 2021, which is incorporated herein by reference in its entirety. [Explanation of Symbols]

[0079] 11 Substrate support 113 Base 114 Electrostatic Chuck 115 Diffusion junction C channel W board

Claims

1. A substrate support part made of a first material, which has electrodes provided inside and is configured to support the substrate, A base made of a second material different from the first material has a flow path configured to allow the temperature control fluid of the substrate to flow through, A diffusion bonding portion formed in the boundary region between the substrate support portion and the base, Equipped with, The difference between the linear thermal expansion coefficient of the first material and the linear thermal expansion coefficient of the second material is 1.0 × 10⁻⁶. －６ / ℃ or lower, The first material includes silicon carbide-containing ceramics, Substrate support.

2. The substrate support according to claim 1, wherein the diffusion junction includes the first material and the second material.

3. The substrate support according to claim 2, wherein the diffusion junction further comprises a third material different from the first and second materials.

4. The second material has a coefficient of thermal expansion of 7.0 × 10 －６ / ℃~9.0×10 －６ A substrate support according to any one of claims 1 to 3, wherein the temperature is / °C.

5. The substrate support according to any one of claims 1 to 4, wherein the second material is titanium or a titanium alloy.

6. The substrate support according to any one of claims 1 to 5, wherein the base has a plurality of grooves arranged concentrically on the surface facing the substrate support portion.

7. The substrate support according to claim 6, wherein each of the plurality of grooves has a plurality of regions divided in the circumferential direction.

8. The system further comprises a heat transfer gas control system for supplying heat transfer gas into the plurality of grooves and controlling the pressure of the heat transfer gas, The heat transfer gas control system is Heat transfer gas supply source, A gas line connecting the plurality of grooves and the heat transfer gas supply source. A pressure control device for controlling the pressure of the heat transfer gas supplied to the plurality of grooves, A pump for reducing pressure in the aforementioned multiple grooves, A recovery tank for recovering the heat transfer gas supplied to the plurality of grooves, including, A substrate support according to claim 6 or 7.

9. A step of bringing into contact the bottom surface of a substrate support made of a first material, which has electrodes provided inside and is configured to support the substrate, with the top surface of a base made of a second material different from the first material, which has a flow path configured to allow the temperature control fluid of the substrate to flow. A step of diffusion bonding the substrate support portion and the base to form a diffusion bond portion in the boundary region between the substrate support portion and the base, Equipped with, The difference between the linear thermal expansion coefficient of the first material and the linear thermal expansion coefficient of the second material is 1.0 × 10⁻⁶. －６ It is below / ℃, The first material includes silicon carbide-containing ceramics, A method for manufacturing a substrate support.

10. The method for manufacturing a substrate support according to claim 9, wherein the step of forming the diffusion junction is to form the diffusion junction by hot pressing the substrate support and the base.

11. The method for manufacturing a substrate support according to claim 10, wherein the hot pressing is performed at a temperature of 2 MPa or more and 500°C or less.

12. Chamber and, A substrate support according to any one of claims 1 to 8, disposed within the chamber, A substrate processing apparatus, including

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