Substrate support assembly and plasma processing apparatus - Patents.com

Abstract

To improve the temperature controllability in a high temperature region in a substrate support body assembly that supports a substrate.SOLUTION: A substrate support body assembly comprises: a base in which a channel for temperature control medium is formed; a substrate support body which has an electrode plate provided on the base and an electrostatic chuck provided on the electrode plate and is configured to support the substrate; a heater for heating the substrate; an elastic member which is provided between the base and the electrode plate, separates the substrate support body from the base, and defines a heat transfer space where the heat transfer gas is supplied to a gap between the base and the electrode plate together with the base and the electrode plate; a fastening member which fastens the base and the electrode plate in a state of holding the elastic member between the base and the electrode plate; and a heat insulation part which suppresses the heat transfer in the gap between the base and the electrode plate via the elastic member.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The present disclosure relates to a substrate support assembly and a plasma processing apparatus. [Background technology]

[0002] Patent Document 1 discloses a film formation apparatus that forms a film on the surface of a workpiece by reacting a predetermined processing gas (raw material gas) in a processing vessel. This film formation apparatus is provided with a mounting table main body (substrate support) on which the workpiece (e.g., a semiconductor wafer) is placed during film formation, and a base that supports the mounting table main body. The mounting table main body is provided with a heating means (heater) for adjusting the temperature of the workpiece, and the base is provided with a cooling means (coolant passage) therein. In addition, in this film formation apparatus, a heat insulating material is provided between the mounting table and the base. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2011-192661 A Summary of the Invention [Problem to be solved by the invention]

[0004] The techniques disclosed herein improve temperature control in high temperature regions of a substrate support assembly that supports a substrate. [Means for solving the problem]

[0005] One aspect of the present disclosure is a substrate support assembly comprising: a base having a flow path for a temperature control medium; a substrate support having an electrode plate provided on the base and an electrostatic chuck provided on the electrode plate and configured to support a substrate; a heater for heating the substrate; an elastic member provided between the base and the electrode plate, the elastic member separating the substrate support from the base and defining, together with the base and the electrode plate, a heat transfer space into which a heat transfer gas is supplied between the base and the electrode plate; a fastening member fastening the base and the electrode plate with the elastic member sandwiched between the base and the electrode plate; and a heat insulating section suppressing heat transfer between the base and the electrode plate via the elastic member. Effect of the Invention

[0006] According to the present disclosure, it is possible to improve temperature controllability in high temperature regions in a substrate support assembly that supports a substrate. [Brief description of the drawings]

[0007] [Figure 1] FIG. 1 is an explanatory diagram illustrating a schematic configuration of a plasma processing system. [Diagram 2] 1 is a vertical cross-sectional view showing an outline of a configuration of a plasma processing apparatus; [Diagram 3] FIG. 2 is an explanatory diagram showing an enlarged view of a portion of the substrate support assembly according to the present embodiment. [Figure 4] FIG. 11 is an explanatory diagram according to a first modified example. [Diagram 5] FIG. 11 is an explanatory diagram according to a second modified example. [Figure 6] FIG. 13 is an explanatory diagram according to a third modified example. [Figure 7] FIG. 13 is an explanatory diagram according to a fourth modified example. [Figure 8] FIG. 13 is an explanatory diagram according to a fourth modified example. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0008] In a manufacturing process of a semiconductor device, a plasma process such as etching is performed on a semiconductor substrate (hereinafter, also referred to as a "substrate") as an object to be processed. In the plasma process, a processing gas is excited to generate plasma, and the substrate is processed by the plasma.

[0009] A plasma processing apparatus for performing plasma processing typically includes a chamber, a substrate support assembly, and a radio frequency (RF) power supply. The RF power supply supplies radio frequency power (RF power) to, for example, an electrode (RF electrode) in the substrate support assembly. In one example, the RF power supply supplies source RF power for generating plasma of a process gas and bias RF power for attracting ions to a substrate. The substrate support assembly is disposed in the chamber. The substrate support assembly includes an RF electrode and an electrostatic chuck on the RF electrode.

[0010] In recent years, in order to accommodate further miniaturization of semiconductor devices, the use of difficult-to-etch mask materials such as BSi, HfO, Ru, and WC has been considered for plasma processing. In order to accommodate such difficult-to-etch materials, it is becoming important to perform plasma processing of substrates in a high-temperature range (e.g., 300°C or higher).

[0011] In order to cope with plasma processing in a high-temperature region, a technology is known in which a sealant is sandwiched between a substrate support and a base and a heat transfer gas such as helium is supplied to the space surrounded by them. As the sealant, an O-ring made of an elastomer such as rubber is generally used. However, an O-ring made of an elastomer has low heat resistance and is difficult to cope with plasma processing in a high-temperature region. Therefore, it is considered to use an O-ring or a C-ring made of a metal such as aluminum or SUS as the sealant. In that case, since the thermal conductivity of metal is extremely large compared to rubber, there is a concern that the sealant becomes a heat path, the surface temperature of the substrate support cannot be efficiently increased, the substrate cannot be sufficiently heated, or high power is required to heat the substrate.

[0012] The technology according to the present disclosure has been made in consideration of the above circumstances, and aims to efficiently increase the surface temperature of a substrate support in a substrate processing apparatus that performs plasma processing on a substrate as a processing target, thereby improving temperature controllability in a high temperature region. Hereinafter, a plasma processing system according to an embodiment and a plasma processing method including an etching method according to this embodiment will be described with reference to the drawings. In this specification and the drawings, elements having substantially the same functional configuration are denoted by the same reference numerals, and duplicated description will be omitted.

[0013] <Plasma processing system> First, a plasma processing system according to an embodiment will be described with reference to Fig. 1. Fig. 1 is an explanatory diagram that shows a schematic configuration of the plasma processing system.

[0014] In one embodiment, the plasma processing system includes a plasma processing device 1 and a controller 2. The plasma processing device 1 includes a plasma processing chamber 10, a substrate support assembly 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, which will be described later, and the gas exhaust port is connected to an exhaust system 40, which will be described later. The substrate support assembly 11 is disposed in the plasma processing space, and has a substrate support surface for supporting a substrate.

[0015] 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 a capacitively coupled plasma (CCP), an inductively coupled plasma (ICP), an electron-cyclotron-resonance plasma (ECR plasma), a helicon wave plasma (HWP), a surface wave plasma (SWP), or the like. Also, various types of plasma generating units may be used, including an alternating current (AC) plasma generating unit and a direct current (DC) plasma generating unit. 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. Thus, 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 200 kHz to 150 MHz.

[0016] The control unit 2 processes computer-executable instructions that cause the plasma processing apparatus 1 to perform various steps described in the present disclosure. The control unit 2 may be configured to control each element of the plasma processing apparatus 1 to perform various steps described herein. In one embodiment, a 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 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).

[0017] <Plasma processing equipment> An example of the configuration of a capacitively coupled plasma processing apparatus as one example of the plasma processing apparatus 1 will be described below with reference to Fig. 2. Fig. 2 is a vertical cross-sectional view showing an outline of the configuration of the plasma processing apparatus 1. In the plasma processing apparatus 1 of this embodiment, plasma processing is performed on a substrate (wafer) W, but the substrate W to be subjected to plasma processing is not limited to a wafer.

[0018] 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 assembly 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 assembly 11 is disposed in the plasma processing chamber 10. The showerhead 13 is disposed above the substrate support assembly 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 assembly 11. The sidewall 10a is grounded. The showerhead 13 and the substrate support assembly 11 are electrically insulated from the housing of the plasma processing chamber 10.

[0019] 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 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 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 include one or more side gas injectors (SGIs) attached to one or more openings formed in the side wall 10a.

[0020] The gas supply 20 may include at least one gas source 21 and at least one flow controller 22. In one embodiment, the gas supply 20 is configured to supply at least one process gas from a respective gas source 21 through a respective flow controller 22 to the showerhead 13. Each flow controller 22 may include, for example, a mass flow controller or a pressure-controlled flow controller. Additionally, the gas supply 20 may include at least one flow modulation device to modulate or pulse a flow rate of the at least one process gas.

[0021] The power source 30 includes an RF power source 31 coupled to the plasma processing chamber 10 via at least one impedance matching circuit. The RF power source 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 of the substrate support assembly 11 and / or a conductive member of the showerhead 13. This causes a plasma to be formed from at least one processing gas supplied to the plasma processing space 10s. In addition, by supplying a bias RF signal to the conductive member of the substrate support assembly 11, a bias potential is generated on the substrate W, and ion components in the formed plasma can be attracted to the substrate W.

[0022] 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 the conductive members of the substrate support assembly 11 and / or the conductive members of the showerhead 13 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 generating unit 31a may be configured to generate a plurality of source RF signals having different frequencies. The generated one or more source RF signals are provided to the conductive members of the substrate support assembly 11 and / or the conductive members of the showerhead 13. The second RF generating unit 31b is coupled to the conductive members of the substrate support assembly 11 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 generator 31b may be configured to generate multiple bias RF signals having different frequencies. The generated bias RF signal or signals are provided to conductive members of the substrate support assembly 11. Also, in various embodiments, at least one of the source RF signal and the bias RF signal may be pulsed.

[0023] 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 a conductive member of the substrate support assembly 11 and configured to generate a first DC signal. The generated first DC signal is applied to the conductive member of the substrate support assembly 11. In one embodiment, the first DC signal may be applied to another electrode, such as an electrode in an electrostatic chuck. In one embodiment, the second DC generator 32b is connected to a conductive member of the showerhead 13 and configured to generate a second DC signal. The generated second DC signal is applied to the conductive member of the showerhead 13. In various embodiments, the first and second DC signals may be pulsed. The first and second DC generating units 32a, 32b may be provided in addition to the RF power supply 31, or the first DC generating unit 32a may be provided in place of the second RF generating unit 31b.

[0024] 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 in the plasma processing space 10s is adjusted by the pressure regulating valve. The vacuum pump may include a turbomolecular pump, a dry pump, or a combination thereof.

[0025] <Substrate Support Assembly> Next, the above-mentioned substrate support assembly 11 and the plasma processing apparatus 1 including the substrate support assembly 11 will be described with reference to Figures 2 and 3. Figure 3 is an explanatory diagram showing an enlarged portion of the substrate support assembly 11.

[0026] The substrate support assembly 11 for supporting the substrate W includes a base 100 and a substrate support 101. The base 100 is supported by a support member 102 extending from the bottom of the plasma processing chamber 10. The support member 102 is an insulating member and is made of, for example, aluminum oxide (alumina). The support member 102 has a substantially cylindrical shape.

[0027] The base 100 is formed of a conductive metal, such as aluminum. The base 100 has a substantially disk shape. The base 100 has a central portion 100a and a peripheral portion 100b. The central portion 100a has a substantially disk shape. The central portion 100a provides a first upper surface 100c of the base 100.

[0028] The peripheral portion 100b has a substantially annular shape in a plan view. The peripheral portion 100b is continuous with the central portion 100a and extends in the circumferential direction outside the central portion 100a in the radial direction. The peripheral portion 100b provides a second upper surface 100d of the base 100. The second upper surface 100d is located lower than the first upper surface 100c in the vertical direction. The peripheral portion 100b, together with the central portion 100a, provides a lower surface 100e of the base 100.

[0029] A flow path 100f for a temperature control medium is formed in the base 100. The flow path 100f extends, for example, in a spiral shape within the base 100. A temperature control medium is supplied to the flow path 100f by a chiller unit 110 provided outside the plasma processing chamber 10. The temperature control medium supplied to the flow path 100f is liquid in the operating temperature range of the plasma processing apparatus 1, for example, a temperature range of 20°C to 250°C. Alternatively, the temperature control medium may be a refrigerant that absorbs heat by vaporization and performs cooling, for example, a hydrofluorocarbon-based refrigerant.

[0030] A power feeder 120 is connected to the base 100. The power feeder 120 is a power feed rod, and is connected to the lower surface 100e of the base 100. The power feeder 120 is made of aluminum or an aluminum alloy. The power feeder 120 is electrically connected to the RF power source 31 of the power source 30 described above.

[0031] The substrate support 101 is provided on the first upper surface 100c side of the base 100. The substrate support 101 has an electrostatic chuck 130 and an electrode plate 131. The electrode plate 131 constitutes a lower electrode, and is provided on the base 100. The electrode plate 131 is conductive. The electrode plate 131 may be made of ceramics, such as aluminum nitride or silicon carbide, which is made conductive, or may be made of a metal (e.g., titanium).

[0032] The electrode plate 131 has a substantially disk-like shape and has a central portion 131a and a peripheral portion 131b. The central portion 131a has a substantially disk-like shape. The central portion 131a provides an upper surface 131c of the electrode plate 131. The upper surface 131c is a substantially circular surface. The peripheral portion 131b is continuous with the central portion 131a and extends in the circumferential direction outside the central portion 131a in the radial direction. In one embodiment, the peripheral portion 131b provides a lower surface 131d of the electrode plate 131 together with the central portion 131a. The peripheral portion 131b also provides an upper surface 131e. This upper surface 131e is a band-like surface and extends in the circumferential direction outside the upper surface 131c in the radial direction. The upper surface 131e is closer to the lower surface 131d than the upper surface 131c in the vertical direction.

[0033] The electrostatic chuck 130 is provided on an electrode plate 131, and is connected to the electrode plate 131, for example, by metal bonding using a metal interposed between the electrostatic chuck 130 and the electrode plate 131. The electrostatic chuck 130 has a substantially disk shape and may be made of ceramics. The ceramics constituting the electrostatic chuck 130 has a melting point of 1×10 in a temperature range of room temperature (for example, 20° C.) to 400° C. 15Ceramics having a volume resistivity of Ω·cm or more may be used. For example, aluminum oxide (alumina), which is a metal oxide, may be used as such ceramics. The electrostatic chuck 130 made of ceramics having such a volume resistivity exhibits sufficient chucking force even in a high temperature range exceeding 200° C. Note that the electrostatic chuck 130 may be made of a dielectric material other than ceramics, such as polyimide.

[0034] The electrostatic chuck 130 incorporates an adsorption electrode 140 and a heater 142. The adsorption electrode 140 is an electrode film, and a direct current (DC) power supply 32 is electrically connected to the adsorption electrode 140. When a DC voltage from the DC power supply 32 is applied to the adsorption electrode 140, an electrostatic force is generated, and the substrate W is held by the electrostatic force. Note that, although a Coulomb type is exemplified as the electrostatic chuck in this embodiment, the present invention is not limited to this, and a Johnsen-Rahbek type may be used for electrostatic adhesion. In this case, the ceramics constituting the electrostatic chuck 130 should have a molecular weight of 1×10 in a temperature range of from room temperature to 400° C. 8 ~1×10 11 A material having a volume resistivity of Ω·cm, such as aluminum nitride, which is a metal nitride, is used.

[0035] The heater 142 is provided below the adsorption electrode 140. The heater 142 is electrically connected to, for example, a heater power supply (not shown) outside the apparatus. A voltage from the heater power supply is applied to the heater 142, and the substrate W is adjusted to a desired temperature.

[0036] An elastic member 160 is provided between the electrode plate 131 (substrate support 101) and the base 100. The elastic member 160 contacts the upper surface 100c of the base 100 and the heat insulating section 220 arranged on the lower surface 131d side of the electrode plate 131. The elastic member 160 separates the substrate support 101 upward from the base 100. The elastic member 160 is, for example, an O-ring. The elastic member 160 is configured to have a thermal resistance higher than the thermal resistance of the heat transfer space 161 when He gas is supplied to the heat transfer space 161. In addition, the elastic member 160 is required to have low thermal conductivity and high heat resistance. Such an elastic member 160 may be made of elastomer or metal. The elastomer elastic member 160 may be formed from FFKM (perfluoroelastomer), FKM (vinylidene fluoride-based fluororubber), silicone, etc. Moreover, the metallic elastic member 160 may be made of aluminum, SUS, Ni-based superalloy, or the like.

[0037] The space surrounded by the base 100, the substrate support 101, and the elastic member 160 constitutes a heat transfer space 161 to which a heat transfer gas is supplied. The heat transfer space 161 is sealed by the elastic member 160 between the base 100 and the substrate support 101. The heat transfer space 161 is configured to receive a heat transfer gas, for example, He gas, from a gas supply unit (not shown) provided outside the plasma processing chamber 10.

[0038] Between the electrode plate 131 (substrate support 101) and the base 100, a heat insulating section 220 is provided on the upper part of the elastic member 160. The heat insulating section 220 has a substantially annular plate shape, and is a member or space having a smaller thermal conductivity than the electrode plate 131. That is, the heat insulating section 220 is a member or space that thermally insulates between the elastic member 160 and the lower surface 131d of the electrode plate 131. The heat insulating section 220 is provided on the peripheral edge 131b side of the lower surface 131d of the electrode plate 131 in the circumferential direction. More specifically, the heat insulating member 220 is provided at least in the range where the elastic member 160 and the lower surface 131d would contact each other if the heat insulating member 220 was not provided. The heat insulating section 220 may be provided on the lower surface 131d of the base 131, for example, from the central portion 131a to the peripheral portion 131b.

[0039] The heat insulating section 220 may be made of a member made of metal, ceramic, resin, or the like having low thermal conductivity. Alternatively, the heat insulating section 220 may be made of a reduced pressure space formed in a predetermined area. In either case, the heat conductivity of the heat insulating section 220 is preferably, for example, 20 W / mK or less. If the heat conductivity is within this range, even in substrate processing in a high temperature area, even if the elastic member 130 is made of an elastomer, the elastic member 130 can be prevented from being heated to a temperature above its heat resistance temperature. Furthermore, even if the elastic member 130 is made of a metal, the amount of heat transmission through the elastic member 130 can be reduced, so that the surface temperature of the substrate support assembly can be efficiently increased.

[0040] When the heat insulating section 220 is configured as a member, the heat insulating section 220 may be, for example, a metal-containing material or ceramics having low thermal conductivity. Examples of metal-containing materials having low thermal conductivity include titanium-containing materials such as pure titanium, 64 titanium (Ti-6Al-4V), and aluminum titanate, and stainless steel. Examples of ceramics include alumina, yttria, zirconia, and glass ceramics. The heat insulating section 220 may be configured from a polymer material as long as it has a heat resistance of 300° C. or more. Examples of such polymer materials include polyimide.

[0041] In addition, when the heat insulating part 220 is configured as a member, the heat insulating part 220 may be a porous material that has been subjected to a surface treatment. For example, the heat insulating part 220 may be configured to include a porous material and a coating material that covers the surface of the porous material, or may be configured as a porous material having a sealing layer that seals the surface. When the surface of the porous material is sealed, the thickness of the sealing layer may be 1 mm or more from the surface of the porous material, or may be 2 mm or more. Examples of the porous material include porous alumina, porous titanium, and porous zirconia. Examples of the coating material or sealing material include metal materials such as aluminum and titanium, and ethyl silicate. The surface treatment can be performed, for example, by cold spraying or impregnation.

[0042] When the heat insulating section 220 is configured as a component, the heat insulating section 220 may be molded integrally with the base 131 by, for example, hot pressing or the like. Alternatively, a step may be provided in the circumferential direction on the outer edge of the lower surface 131d of the base 131, and the heat insulating section 220 may be attached to this step by any method such as welding, spraying, bonding, adhesion, bolting, etc. The heat insulating section 220 may be positioned so as to be embedded in the base 131, or may be attached to the surface of the base 131 (here, the lower surface 131d).

[0043] In addition, when the heat insulating section 220 is a reduced pressure space, for example, a space may be formed in the circumferential direction on the lower surface 131d side of the base 131, and the space may be reduced in pressure. When the reduced pressure space is configured as the heat insulating section 220, the reduced pressure space may have a single layer structure or a multi-layer structure. By using a multi-layer structure, the heat insulating effect can be further improved.

[0044] The substrate support assembly 11 further includes a clamping member 170. The clamping member 170 is configured to clamp the elastic member 160 between the base 100 and the electrode plate 131. The clamping member 170 may be formed from a material having low thermal conductivity, for example, a titanium-containing material such as titanium or a titanium alloy, to suppress heat conduction from the clamping member 170 between the electrode plate 131 and the base 100.

[0045] The fastening member 170 has a tubular portion 170a and an annular portion 170b. The tubular portion 170a has a generally cylindrical shape and provides a first lower surface 170c at its lower end. The annular portion 170b has a generally annular plate shape and extends radially inward from the tubular portion 170a, continuing from the inner edge of the upper part of the tubular portion 170a. The annular portion 170b provides a second lower surface 170d.

[0046] The fastening member 170 is disposed such that the first lower surface 170c contacts the upper surface 100d of the base 100, and the second lower surface 170d contacts the upper surface 131e of the electrode plate 131. The fastening member 170 may be fixed to the peripheral portion 100b of the base 100 by bolts 171, for example. In this case, the amount of squashing (compression) of the elastic member 160 is adjusted by adjusting the fastening torque of the bolts 171 applied to the fastening member 170.

[0047] An elastic member 175 may be provided between the second lower surface 170d of the fastening member 170 and the upper surface 131e of the electrode plate 131. This elastic member 175 may be an O-ring, and prevents particles (e.g., metal powder) that may be generated due to friction between the second lower surface 170d and the upper surface 131e from moving into the plasma processing space 10s.

[0048] Although not shown here, a heat insulating space having a heat insulating effect may be formed between the first lower surface 170c of the fastening member 170 and the upper surface 100d of the base 100. This heat insulating space may be configured to be depressurized when the plasma processing chamber 10 is evacuated.

[0049] An edge ring 180 and an electrostatic chuck 181 for the edge ring are provided on the upper surface side of the fastening member 170. In addition to the edge ring 180 and the electrostatic chuck 181 for the edge ring, an edge ring temperature adjustment unit 182 may be provided on the upper surface side of the fastening member 170. The edge ring 180, the electrostatic chuck 181 for the edge ring, and the edge ring temperature adjustment unit 182 may be stacked in this order from top to bottom. The edge ring 180 is disposed so as to surround the substrate W placed on the substrate support 101 (electrostatic chuck 130). The edge ring 180 improves the uniformity of the plasma processing on the substrate W.

[0050] The electrostatic chuck 181 for edge ring has a configuration similar to that of the electrostatic chuck 130, that is, the electrostatic chuck 181 for edge ring has a configuration in which an adsorption electrode 191 is provided inside a base layer 190. The base layer 190 has a substantially circular ring shape in a plan view. The base layer 190 may be formed of, for example, the same material as the electrostatic chuck 130. In addition, the base layer 190 can be selected depending on the electrostatic force (Coulomb force or Johnsen-Rahbek force) used to adsorb and hold the substrate W.

[0051] The chucking electrode 191 is a conductive electrode film having a substantially circular ring shape. A DC power supply outside the apparatus is electrically connected to the chucking electrode 191. When a DC voltage from the DC power supply is applied to the chucking electrode 191, the edge ring support 181 generates an electrostatic force of Coulomb force or Johnsen-Rahbek force, and holds the edge ring 180 by the electrostatic force. The chucking electrode 191 may be composed of a plurality of electrodes configured to generate different potentials. In one example, the chucking electrode 191 is composed of a circular inner electrode arranged on the side of the center part 131a of the base 131, and a circular outer electrode arranged on the outside of the inner electrode.

[0052] The edge ring temperature adjustment unit 182 has a configuration in which a heater electrode 201 is provided inside a base layer 200. The base layer 200 has a substantially circular ring shape in a plan view. The base layer 200 may be formed from the same material as the base layer 190 described above.

[0053] The heater electrode 201 is electrically connected to a heater power supply external to the apparatus. When a voltage from the heater power supply is applied to the heater electrode 201, the edge ring 180 is adjusted to a desired temperature.

[0054] In addition, in the substrate support assembly 11, a gas line (not shown) for supplying a heat transfer gas (e.g., He gas) between the substrate W and the electrostatic chuck 130 is provided. Between the substrate W and the electrostatic chuck 130, a gas diffusion space (not shown) in which the heat transfer gas diffuses is formed.

[0055] <Plasma treatment method> Next, a plasma process performed using the plasma processing system configured as above will be described. As the plasma process, for example, an etching process or a film formation process is performed.

[0056] First, the substrate W is carried into the plasma processing chamber 10, and the substrate W is placed on the electrostatic chuck 130. Thereafter, a DC voltage is applied to the attraction electrode 140 of the electrostatic chuck 130, whereby the substrate W is electrostatically attracted and held by the electrostatic chuck 130 by Coulomb force or Johnsen-Rahbek force. After the substrate W is carried in, the inside of the plasma processing chamber 10 is depressurized to a desired vacuum level by the exhaust system 40.

[0057] Next, a processing gas is supplied from the gas supply unit 20 to the plasma processing space 10s via the shower head 13. In addition, a source RF power for generating plasma is supplied to the electrode plate 131 by the RF power supply 31. Then, the processing gas is excited to generate plasma. At this time, the RF power supply 31 may supply a bias RF power for attracting ions. Then, the substrate W is subjected to plasma processing by the action of the generated plasma.

[0058] <Effects of the technology disclosed herein> According to the above embodiment, the substrate support assembly 11 is configured such that the heat insulating portion 220 is provided between the electrode plate 131 and the elastic member 160. Therefore, even if the elastic member 160 is made of an elastomer having a relatively low heat resistance, damage or deterioration of the elastic member 160 can be suppressed during substrate processing in a high temperature range (e.g., 300° C. or higher).

[0059] Furthermore, even if the elastic member 160 is made of a metal having high thermal conductivity, it is possible to reduce the amount of heat transmitted through the elastic member 160, and efficiently increase the surface temperature of the substrate support assembly 11. In other words, the output of the heater 142 required to heat or maintain the temperature of the substrate W is reduced, improving energy efficiency and saving energy.

[0060] In addition, by providing the heat insulating portion 220 between the electrode plate 131 and the elastic member 160, a local temperature drop around the elastic member 160 is reduced. This improves the in-plane uniformity of the surface temperature of the electrostatic chuck 130, and also makes it possible to improve the in-plane uniformity of the temperature of the substrate W.

[0061] The embodiments disclosed herein should be considered as illustrative and not restrictive in all respects. The above-described embodiments may be omitted, substituted, or modified in various forms without departing from the scope and spirit of the appended claims.

[0062] <Modifications of the present disclosure> In the above embodiment, the substrate support assembly 11 is illustrated and described as having a heat insulating section 220 between the electrode plate 131 and the elastic member 160, but the scope of the present disclosure is not limited to this, and various configurations of the heat insulating section 220 are possible. Therefore, modifications of the present disclosure will be described below with reference to the drawings. Note that in the following modifications, components having the same functional configuration as those in the above embodiment are illustrated with the same reference numerals, and their description may be omitted.

[0063] (First Modification) FIG. 4 is an explanatory diagram according to a first modified example, showing an enlarged view of a part of the substrate support assembly 11. As shown in FIG.

[0064] 4, in the configuration according to the first modification, the substrate support 101 has an electrostatic chuck 130, an electrode plate 131, and a temperature adjustment unit 132 arranged in this order from above. Similar to the electrostatic chuck 130, the temperature adjustment unit 132 is coupled to the electrode plate 131 (lower surface 131d) by metal bonding using a metal interposed between the electrode plate 131 and the base 131. Similar to the electrostatic chuck 130, the temperature adjustment unit 132 has a substantially disk shape and is made of ceramics.

[0065] In this modification, an attraction electrode 140 is built in the electrostatic chuck 130, and a heater 142 is built in the temperature adjustment unit 132. That is, in the substrate support 101, the attraction electrode 140 and the heater 142 are provided so as to be spaced apart from each other above and below with the electrode plate 131 interposed therebetween. A heat insulating unit 220 is provided on the outer side of the temperature adjustment unit 132 in the circumferential direction.

[0066] The configuration according to this modification has the following advantages in addition to the effects described in the above embodiment. That is, the substrate support 101 has a structure in which the electrostatic chuck 130 having the chucking electrode 140 and the temperature adjustment unit 132 having the heater 142 are separated vertically, and the electrode plate 131 is sandwiched between the electrostatic chuck 130 and the temperature adjustment unit 132. By separating the chucking electrode 140 and the heater 142 in this manner, the thickness of the electrostatic chuck 130 can be reduced, and as a result, the loss of RF power on the low frequency side, for example, 400 kHz, can be suppressed. In addition, the potential difference between the substrate W and the electrode plate 131 can be reduced, and abnormal discharge on the back surface of the substrate W can be suppressed.

[0067] (Second Modification) FIG. 5 is an explanatory diagram according to a second modified example, showing an enlarged view of a part of the substrate support assembly 11. As shown in FIG.

[0068] As shown in FIG. 5, in the configuration according to the second modification, a heat insulating portion 220 is provided below the elastic member 160. As shown in FIG.

[0069] In the configuration according to this modification, since the electrode plate 131 and the elastic member 160 are in contact with each other, it is preferable that the elastic member 160 is made of metal rather than elastomer. According to this modification, since a heat insulating effect is obtained by the heat insulating portion 220 between the base 100 and the elastic member 160, it is possible to reduce the amount of heat transmitted through the elastic member 160, as in the above embodiment, and the surface temperature of the substrate support assembly 11 can be efficiently increased. In other words, the output of the heater 142 required to heat or maintain the temperature of the substrate W is reduced, thereby improving energy efficiency and saving energy.

[0070] (Third Modification) FIG. 6 is an explanatory diagram according to a third modified example, showing an enlarged view of a part of the substrate support assembly 11. In FIG.

[0071] 6, in the configuration according to the third modification, heat insulating portions 220 (here, first heat insulating portion 220a and second heat insulating portion 220b) are provided on both the upper and lower portions of the elastic member 160. According to the configuration according to this modification, a further improvement in heat insulating performance is achieved around the elastic member 160. That is, when it is required to heat the electrostatic chuck 130 to a high temperature, it is possible to efficiently raise the temperature of the electrostatic chuck 130 to a temperature equal to or higher than the heat resistance temperature of the elastic member 160.

[0072] (Fourth Modification) 7 and 8 are explanatory views according to a fourth modified example, showing an enlarged view of a part of the substrate support assembly 11. In FIG.

[0073] As shown in Fig. 7 and Fig. 8, in the configuration according to the fourth modification, a first elastic member 160a and a second elastic member 160b are arranged above and below a heat insulating section 220 between the base 100 and the electrode plate 131 so as to sandwich the heat insulating section 220. As a specific configuration, the first elastic member 160a, the second elastic member 160b, and the heat insulating section 220 may be configured as an integrated member as shown in Fig. 7. Alternatively, as shown in Fig. 8, the first elastic member 160a, the heat insulating section 220, and the second elastic member 160b may be configured as separate members stacked from the top in this order.

[0074] In the configuration according to this modification, the material of the first elastic member 160a and the material of the second elastic member 160b may be the same or different. For example, since the temperature of the electrode plate 131 is generally higher than that of the base 100, the first elastic member 160a in contact with the electrode plate 131 may be made of metal, and the second elastic member 160b in contact with the base 100 may be made of elastomer.

[0075] According to the configuration of this modification, there is no need to join the heat insulating section 220 to the base 100 or the electrode plate 131. Therefore, in addition to the effects described in the above embodiment, there is an advantage that the device can be manufactured more easily.

[0076] In the above embodiment and modified examples, the edge ring 180 is attracted and held by the electrostatic chuck 181 for the edge ring, but the method of holding the edge ring 180 is not limited to this. For example, the edge ring 180 may be attracted and held by using an attraction sheet, or the edge ring 180 may be clamped and held. Alternatively, the edge ring 180 may be held by its own weight. In such a case, the electrostatic chuck 181 for the edge ring is omitted. [Explanation of symbols]

[0077] 1. Plasma processing equipment 10 Plasma Processing Chamber 10s Plasma treatment space 11 Substrate Support Assembly 100 bases 101 Substrate support 130 Electrostatic Chuck 131 Electrode Plate 140 Adsorption electrode 142 Heater 160 Elastic member 170 Fastening member 220 Insulation section W substrate

Claims

1. A base in which a flow path for a temperature control medium is formed; a substrate support configured to support a substrate, the substrate support having an electrode plate provided on the base and an electrostatic chuck provided on the electrode plate; a heater for heating the substrate; an elastic member provided between the base and the electrode plate, the elastic member separating the substrate support from the base and defining, together with the base and the electrode plate, a heat transfer space to which a heat transfer gas is supplied between the base and the electrode plate; a fastening member that fastens the base and the electrode plate together in a state in which the elastic member is sandwiched between the base and the electrode plate; a heat insulating portion that suppresses heat transfer between the base and the electrode plate via the elastic member; A substrate support assembly comprising:

2. The substrate support assembly of claim 1 , wherein the heater is integral to the electrostatic chuck.

3. The substrate support assembly of claim 1 , wherein the heater is built into a temperature control unit disposed on a lower surface side of the electrode plate.

4. The substrate support assembly of any one of claims 1 to 3, wherein the thermal insulation has a thermal conductivity of 20 W / mK or less.

5. The substrate support assembly of any one of claims 1 to 4, wherein the thermal insulation portion is comprised of a material including at least one selected from the group consisting of titanium-containing materials, stainless steel, alumina, yttria, zirconia, glass ceramics, and polyimide.

6. The substrate support assembly according to any one of claims 1 to 4, wherein the thermal insulation portion is one or more layers of reduced pressure space provided within the base and / or the electrode plate.

7. The substrate support assembly of any one of claims 1 to 4, wherein the thermal insulation portion comprises a porous material and a coating material covering a surface of the porous material.

8. The substrate support assembly of any one of claims 1 to 4, wherein the thermal insulation portion is a porous material having a sealing layer on a surface thereof.

9. The substrate support assembly of claim 8 , wherein the sealing layer has a thickness of 1 mm or more from a surface of the porous material.

10. The substrate support assembly of any one of claims 7 to 9, wherein the porous material is comprised of alumina oxide, titanium oxide or zirconia.

11. A substrate support assembly according to any preceding claim, wherein the thermal insulation is provided between the electrode plate and the elastic member.

12. The substrate support assembly of claim 11 , wherein the resilient member is made of an elastomer or metal.

13. The substrate support assembly of claim 12 , wherein the elastic member is comprised of at least one material selected from the group consisting of FFKM, FKM, silicone, aluminum, SUS, and Ni-based superalloys.

14. The substrate support assembly of any one of claims 1 to 10, wherein the thermal insulation portion is provided between the base and the elastic member.

15. The substrate support assembly of claim 14 , wherein the thermal insulation is made of metal.

16. The substrate support assembly of any preceding claim, wherein a thermally insulating space is formed between the clamping member and the base.

17. a chamber having at least one gas inlet and at least one gas outlet; a substrate support assembly disposed within the chamber; A plasma generating unit; A plasma processing apparatus comprising: The substrate support assembly includes: A base in which a flow path for a temperature control medium is formed; a substrate support configured to support a substrate, the substrate support having an electrode plate provided on the base and an electrostatic chuck provided on the electrode plate; a heater for heating the substrate; an elastic member provided between the base and the electrode plate, the elastic member separating the substrate support from the base and defining, together with the base and the electrode plate, a heat transfer space to which a heat transfer gas is supplied between the base and the electrode plate; a fastening member that fastens the base and the electrode plate together in a state in which the elastic member is sandwiched between the base and the electrode plate; a heat insulating portion that suppresses heat transfer between the base and the electrode plate via the elastic member; A plasma processing apparatus comprising:

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