Substrate support and plasma processing apparatus

A substrate support includes a substrate supporting surface, an electrode, a power supply line, and a power supply terminal. The electrode is disposed below the substrate supporting surface and configured to provide a bias power. The power supply line is disposed below the electrode and configured to apply the bias power to the electrode. The power supply terminal is configured to electrically couple the electrode and the power supply line. Further, an area of a surface of the power supply terminal that is coupled to the electrode is greater than an area of a surface of the power supply terminal that is coupled to the power supply line.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims priority to Japanese Patent Application No. 2019-181574, filed on Oct. 1, 2019, the entire contents of which are incorporated herein by reference.

TECHNICAL FIELD

The present disclosure relates to a substrate support and a plasma processing apparatus.

BACKGROUND

An electrostatic chuck and an edge ring (also referred to as “focus ring”) are placed on a substrate supporting surface of a substrate support of a plasma processing apparatus. An attracting electrode, an electrode for providing a bias power, a heater, or the like may be embeded in each of the electrostatic chuck and the edge ring. For example, Japanese Patent Application Publication No. 2018-110216 discloses a cylindrical contact structure coupled to an electrode as a power supply terminal.

When a current flows through the power supply terminal, heat is generated at a contact portion, which may result in a non-uniform temperature distribution of a substrate.

The present disclosure provides a technique capable of improving in-plane uniformity of a substrate temperature.

SUMMARY

In accordance with an aspect of the present disclosure, there is provided a substrate support including: a substrate supporting surface; at least one electrode disposed below the substrate supporting surface and configured to provide a bias power; a power supply line disposed below the electrode and configured to apply the bias power to the electrode; and one or more power supply terminals configured to electrically couple the electrode and the power supply line, wherein an area of a surface of each of the power supply terminals that is coupled to the electrode is greater than an area of a surface of each of the power supply terminals that is coupled to the power supply line.

DETAILED DESCRIPTION

Hereinafter, embodiments of the present disclosure will be described in detail with reference to the accompanying drawings. Like reference numerals will be given to like or corresponding parts throughout the drawings and redundant description thereof will be omitted.

FIG.1schematically shows a plasma processing apparatus1according to an embodiment. The plasma processing apparatus1shown inFIG.1is a capacitively coupled plasma processing apparatus. The plasma processing apparatus1includes a chamber10. The chamber10has an inner space10stherein.

The chamber10includes a chamber body12. The chamber body12has a substantially cylindrical shape and has the inner space10stherein. The chamber body12is formed of, for example, aluminum. A corrosion resistant film is formed on an inner wall surface of the chamber body12. The corrosion resistant film may be a film made of ceramic such as aluminum oxide or yttrium oxide.

The chamber body12has a sidewall having a port12p. A substrate W is transferred between the inner space10sand the outside of the chamber10through the port12p. The port12pcan be opened and closed by a gate valve12gdisposed on the sidewall of the chamber body12.

A support13is disposed on the bottom of the chamber body12. The support13is formed of an insulating material and has a substantially cylindrical shape. In the inner space10s, the support13extends upward from the bottom of the chamber body12. A member15is disposed on the support13. The member15may be made of an insulating material such as quartz. The member15may be an annular plate-shaped body.

The plasma processing apparatus1further includes a substrate support14according to an exemplary embodiment. The substrate support14is disposed in the inner space10sand supported by the support13. The substrate support14is configured to support the substrate W in the chamber10, i.e., in the inner space10s.

The substrate support14includes a lower electrode18and an electrostatic chuck (ESC)20according to an exemplary embodiment. The substrate support14may further include an electrode plate16. The electrode plate16is formed of a conductor such as aluminum and has a substantially disk shape. The lower electrode18is disposed on the electrode plate16. The lower electrode18is formed of a conductor such as aluminum (Al) or titanium (Ti) and has a substantially disk shape. The lower electrode18is electrically coupled to the electrode plate16. An outer peripheral surface of the lower electrode18and an outer peripheral surface of the electrode plate16are surrounded by the support13. The electrode plate16and the lower electrode18are an example of a base that supports the electrostatic chuck20.

The electrostatic chuck20is disposed on the lower electrode18. An edge of the electrostatic chuck20and an edge ring26are surrounded by the member15. The electrostatic chuck20supports the substrate W and the edge ring26according to an exemplary embodiment.

The substrate W has, e.g., a disk shape and is placed onto the electrostatic chuck20. The edge ring26is placed onto the electrostatic chuck20to surround an edge of the substrate W. An outer edge portion of the edge ring26may extend to be positioned above an inside edge of the member15. The edge ring26is an annular member. The edge ring26may be formed of, but not limited to, silicon, silicon carbide, or quartz. The edge ring26is also referred to as a “focus ring.”

The lower electrode18has an internal flow channel18f. A heat exchange medium (e.g., a coolant) is supplied to the internal flow channel18ffrom a chiller unit (CU)22through a line22a. The chiller unit22is disposed external to the chamber10. The heat exchange medium supplied to the internal flow channel18freturns to the chiller unit22through a line22b. In the plasma processing apparatus1, a temperature of the substrate W placed on the electrostatic chuck20is adjusted by heat exchange between the heat exchange medium and the lower electrode18.

The plasma processing apparatus1further includes a gas supply line24. The gas supply line24is provided to supply a heat transfer gas (e.g., He gas) from a heat transfer gas supply mechanism to a space between an upper surface of the electrostatic chuck20and a back surface of the substrate W.

The plasma processing apparatus1further includes an upper electrode30. The upper electrode30is disposed above the substrate support14. The upper electrode30is supported at an upper portion of the chamber body12with a member32. The member32is formed of an insulating material. The upper electrode30and the member32close a top opening of the chamber body12.

The upper electrode30may include a ceiling plate34and a holder36. A bottom surface of the ceiling plate34that faces the inner space10sdefines the inner space10s. The ceiling plate34may be formed of a semiconductor or a low-resistance conductor with low Joule heating. The ceiling plate34has multiple gas injection holes34aextending therethrough in a thickness direction (vertical direction).

The holder36detachably holds the ceiling plate34. The holder is formed of a conductive material such as aluminum. The holder36has an internal gas diffusion space36a. Multiple gas holes36bare formed in the holder36. The gas holes36bextend downward from the gas diffusion space36a. The gas holes36bcommunicate with the gas injection holes34a, respectively. The holder36has a gas inlet port36c. The gas inlet port36cis connected to the gas diffusion space36a. A gas supply line38is connected to the gas inlet port36c.

The gas supply line38is connected to a gas supply unit GS. The gas supply unit GS includes a gas source group (GSG)40, a valve group (VG)41, a flow rate controller group (FRCG)42, and a valve group (VG)43. The gas source group40is connected to the gas supply line38through the valve group41, the flow rate controller group42, and the valve group43. The gas source group40includes multiple gas sources. Each of the valve group41and the valve group43includes multiple opening/closing valves. The flow rate controller group42includes multiple flow rate controllers. Each of the flow rate controllers of the flow rate controller group42is a mass flow controller or a pressure control type flow rate controller. The gas sources of the gas source group40are connected to the gas supply line38through the corresponding opening/closing valves of the valve group41, the corresponding flow rate controllers of the flow rate controller group42, and the corresponding opening/closing valves of the valve group43.

In the plasma processing apparatus1, a shield46is detachably disposed and extends along an inner wall surface of the chamber body12. The shield46is also disposed on an outer peripheral surface of the support13. The shield46prevents reaction products such as etching by-products or the like from being adhered to the chamber body12. The shield46is obtained by forming a corrosion resistant film on a surface of an aluminum base, for example. The corrosion resistant film may be a film made of ceramic such as yttrium oxide.

A baffle plate48is disposed between the support13and the sidewall of the chamber body12. The baffle plate48may be obtained by forming a corrosion resistant film on a surface of an aluminum base, for example. The corrosion resistant film may be a film made of ceramic such as yttrium oxide. The baffle plate48has multiple through-holes. At the bottom portion of the chamber body12, a gas exhaust port12eis disposed below the baffle plate48. A gas exhaust unit (GEU)50is connected to the gas exhaust port12ethrough a gas exhaust line52. The gas exhaust unit50includes a pressure control valve, and a vacuum pump such as a turbo molecular pump.

The plasma processing apparatus1further includes a first radio frequency (RF) power supply61for applying a RF power HF for plasma generation. The first RF power supply61is configured to generate the RF power HF in order to generate plasma from a gas in the chamber10. The RF power HF has a frequency ranging from, e.g., 27 MHz to 100 MHz.

The first RF power supply61is electrically coupled to the lower electrode18through a matching unit (MU)63. The matching unit63has a matching circuit configured to match an impedance of a load side (the lower electrode side) of the first RF power supply61and an output impedance of the first RF power supply61. Alternatively, in other embodiments, the first RF power supply61may be electrically coupled to the upper electrode30through the matching unit63.

The plasma processing apparatus1may further include a second RF power supply62for applying RF power LF for ion attraction. The second RF power supply62is configured to generate the RF power LF. The RF power LF has a frequency mainly suitable for attracting ions to the substrate W, e.g., a frequency ranging from 400 kHz to 13.56 MHz. Alternatively, the RF power LF may be a pulse-shaped voltage having a rectangular waveform.

The second RF power supply62is electrically coupled, through a matching unit (MU)64, to a bias electrode21in the electrostatic chuck20that is connected to a power supply line102. The matching unit64has a matching circuit configured to match an impedance of a load side (lower electrode side) of the second RF power supply62and an output impedance of the second RF power supply62.

The plasma processing apparatus1further includes a controller (CNT)80. The controller80may be a computer including a processor, a storage device such as a memory, an input device, a display device, a signal input/output interface, and the like, and controls the individual components of the plasma processing apparatus1. In the controller80, an operator can input commands through the input device to manage the plasma processing apparatus1. Further, in the controller80, the display can visualize and display an operation status of the plasma processing apparatus1. A control program and recipe data are stored in the storage device of the controller80. The control program is executed by the processor of the controller80to perform various processes in the plasma processing apparatus1. When the processor of the controller80executes the control program and controls the individual components of the plasma processing apparatus1based on the recipe data, various processes such as plasma processing and the like are performed in the plasma processing apparatus1.

Hereinafter, the substrate support14according to the embodiment will be described in detail with reference toFIG.2andFIG.3in addition toFIG.1.FIG.2shows an example of a structure of the substrate support14according to the embodiment.FIG.3shows an example of an electrical coupling between power supplies and electrodes of the substrate support14according to the embodiment.

The electrostatic chuck20includes a main body having a first region and a second region as shown inFIG.2. The main body of the electrostatic chuck20has a stepped portion at an outer periphery thereof and is formed of a dielectric material such as alumina (Al2O3), aluminum nitride (AlN), or the like.

The first region has a substantially disk shape. The first region has a first substrate supporting surface201onto which the substrate W is placed. The first region is configured to attract and hold the substrate W placed onto the first substrate supporting surface201. A diameter of the first region is smaller than that of the substrate W.

The second region has an annular shape. The second region shares a central axis (axis AX shown inFIG.2) with the first region. The second region has a second substrate supporting surface202. The second region is disposed as one body to surround the first region and configured to support the edge ring26placed onto the second substrate supporting surface202(seeFIG.1).

The dielectric material forming the first region may be the same as that forming the second region. For example, the main body of the electrostatic chuck20may be formed of ceramic such as aluminum oxide or aluminum nitride. The electrostatic chuck20has, as the substrate supporting surface, the first substrate supporting surface201and the second substrate supporting surface202. The second substrate supporting surface202in the second region is lower than the first substrate supporting surface201in the first region. A thickness of the first region is greater than that of the second region.

The electrostatic chuck20further includes an attracting electrode23. The attracting electrode23is disposed in the first region of the main body. The attracting electrode23is connected to a direct-current (DC) power supply20pthrough a switch20s(seeFIGS.1and3). When a DC voltage from the DC power supply20pis applied to the attracting electrode23, an electrostatic attraction force is generated between the first region of the main body and the substrate W. Due to the generated electrostatic attraction force, the substrate W is attracted to and held on the first region of the main body.

The electrostatic chuck20further includes attracting electrodes27aand27b(hereinafter, collectively referred to as “attracting electrode27”). The attracting electrodes27aand27bare disposed in the second region of the main body. The attracting electrodes27aand27bcircumferentially extend about the central axis of the electrostatic chuck20. The attracting electrode27bis disposed outside the attracting electrode27a. As shown inFIG.3, a DC power supply (DC)20mis electrically coupled to the attracting electrode27athrough a switch20n, and a DC power supply (DC)20ris electrically coupled to the attracting electrode27bthrough a switch20t. DC voltages are applied from the DC power supplies20mand20rto the attracting electrodes27aand27bsuch that a potential difference is generated between the attracting electrodes27aand27b. For example, the polarity of the DC voltage applied from the DC power supply20mto the attracting electrode27amay be opposite to that of the DC voltage applied from the DC power supply20rto the attracting electrode27b. However, the attracting electrode27is not limited to a bipolar electrode and may be a monopolar electrode. When the DC voltages are applied from the DC power supplies20mand20rto the attracting electrodes27aand27b, an electrostatic attraction force is generated between the second region of the main body and the edge ring26. Due to the generated electrostatic attraction force, the edge ring26is attracted to and held on the second region of the main body.

As shown inFIG.3, the bias electrode21is disposed below the first substrate supporting surface201and below the attracting electrode23. A bias electrode25is disposed below the second substrate supporting surface202and below the attracting electrodes27aand27b. A third RF power supply65is electrically coupled to the bias electrode25connected to a power supply line112through a matching unit (MU)66(seeFIGS.1and2). The matching unit66has a matching circuit. The matching circuit of the matching unit66is configured to match an impedance of a load side (the lower electrode side) of the third RF power supply65and an output impedance of the third RF power supply65.

Each of the bias electrodes21and25is disposed to provide a bias power for ion attraction. A DC voltage or a RF voltage is applied to be the bias power. In the example ofFIGS.1and2, the bias electrode25provides the bias power by applying a RF power from the third RF power supply65. However, the present disclosure is not limited thereto, and the bias power may be provided by applying a DC voltage from the DC power supply. When the bias power is applied to the bias electrode21, ions in the plasma are attracted toward the first region of the main body. Accordingly, the process characteristics, such as an etching rate, a film forming rate, and the like, on the entire surface of the substrate W can be controlled. When the bias power is applied to the bias electrode25, the ions in the plasma are attracted toward the second region of the main body. Accordingly, the process characteristics on the edge region of the substrate W can be controlled.

The bias electrodes21and25are examples of an electrode disposed below the substrate supporting surface of the electrostatic chuck20to provide the bias power. The bias electrode21is an example of a first electrode disposed below the first substrate supporting surface201, and the bias electrode25is an example of a second electrode disposed below the second substrate supporting surface202. The bias powers applied to the bias electrodes21and25are independently controlled by the second RF power supply62and the third RF power supply65, respectively. The electrode for providing the bias power may include at least one of the bias electrode21and the bias electrode25.

The attracting electrode23in the first region is disposed between the first substrate supporting surface201and the bias electrode21. The attracting electrode23and the bias electrode21are formed in a disk shape and have substantially the same diameter. The attracting electrodes27aand27bin the second region are disposed between the second substrate supporting surface202and the bias electrode25. The attracting electrodes27aand27band the bias electrode25have an annular shape. Radial widths of the attracting electrodes27aand27bare substantially the same, and a radial width of the bias electrode21is greater than the sum of the radial widths of the attracting electrodes27aand27b. The attracting electrodes23,27a, and27bare examples of an electrode disposed between the electrode for providing the bias power and the substrate supporting surface of the electrostatic chuck20to generate an electrostatic attraction. The electrode for generating the electrostatic attraction may include at least one of the attracting electrodes23and27. Accordingly, at least one of the substrate W and the edge ring26is electrostatically attracted and held. Further, the electrode for providing the bias power and the electrode for generating the electrostatic attraction are disposed in the same dielectric.

The bias electrode21and the attracting electrodes27aand27bare disposed on the same plane of the electrostatic chuck20. As shown inFIG.3, a thickness D1from the first substrate supporting surface201shown inFIG.2to an upper surface of the bias electrode21is equal to a thickness D2from the second substrate supporting surface202to an upper surface of the bias electrode25.

When the RF power LF is applied to the electrode plate16, a potential difference is generated between the electrode plate16and the substrate W depending on an electrostatic capacitance between the electrode plate16and the substrate W and a potential difference is generated between the electrode plate16and the edge ring26an electrostatic capacitance between the electrode plate16and the edge ring26. Therefore, the heat transfer gas supplied to the back surface of the substrate W and a back surface of the edge ring26is ionized. Accordingly, abnormal discharge may occur on the back surface of the substrate W and/or the back surface of the edge ring26. Hence, in the substrate support14according to the present embodiment, the bias electrodes21and25are disposed in the electrostatic chuck20to suppress the discharge of the heat transfer gas. As a result, the RF power LF can be applied to the bias electrodes21and25.

As shown inFIG.2, the substrate support14includes a contact pin100that electrically couples the bias electrode21and the power supply line102that is disposed below the bias electrode21to apply a bias power. The contact pin100has a tapered shape such that an area of an upper surface100acoupled to the bias electrode21is greater than that of a bottom surface100bcoupled to the power supply line102. The contact pin100is formed of a conductive material. The contact pin100may be formed of, e.g., conductive ceramic. The power supply line102has at a tip end thereof a metal terminal103made of a metal material such as copper (Cu), titanium (Ti), or the like, and the contact pin100couples the bias electrode21and the metal terminal103. Accordingly, the power supply line102is partially disposed in the substrate support14, and a part (the metal terminal103) of the power supply line102may be exposed on the bottom surface of the substrate support14(bottom surface182of the lower electrode18). As a result, the RF power LF from the second RF power supply62is applied to the bias electrode21through the power supply line102(the metal terminal103) and the contact pin100.

Further, the substrate support14includes a contact pin110that electrically couples the bias electrode25and the power supply line112that is disposed below the bias electrode25to apply a bias power. The contact pin110has a tapered shape such that an area of an upper surface110acoupled to the bias electrode25is greater than that of a bottom surface110bcoupled to the power supply line112. The contact pin110is formed of a conductive material. The contact pin110may be formed of, e.g., conductive ceramic. The power supply line112has at a tip end thereof a metal terminal113made of a metal material, and the contact pin110couples the bias electrode25and the metal terminal113. Accordingly, the power supply line112is partially disposed in the substrate support14, and a part (the metal terminal113) of the power supply line112may be exposed on the bottom surface of the substrate support14(the bottom surface182of the lower electrode18). As a result, the RF power from the third RF power supply65is applied to the bias electrode25through the power supply line112(the metal terminal113) and the contact pin110.

The contact pins100and110are examples of a power supply terminal that electrically couples the electrode for providing the bias power and the power supply line.

The structural characteristics of the contact pin100according to the present embodiment shown inFIG.4Bwill be described while comparing a shape of the contact pin100with that of a conventional contact pin300shown inFIG.4A. Since the contact pin110has the same structural characteristics as the contact pin100, the description thereof will be omitted.

The conventional contact pin300has a cylindrical shape, and an area S1of its upper surface300ais equal to an area S2of its bottom surface300b. When the RF bias power LF is supplied from the second RF power supply62, a relatively high current flows through the contact pin300for a short period of time. Therefore, Joule heat is generated and the contact pin300emits heat. Accordingly, a temperature of a portion of the substrate W positioned above the contact pin300becomes higher than that of other portions of the substrate W, which makes it difficult to control the in-plane temperature distribution of the substrate W to be uniform.

Therefore, the contact pin100according to the present embodiment has a tapered shape, and the area S1of the upper surface100ais greater than the area S2of the bottom surface100bas shown inFIG.4B. By increasing the area S1of the upper surface100aof the contact pin100, it is possible to reduce electric resistance on the upper surface100aand to suppress the heat emission of the contact pin100.

Further, by decreasing the area S2of the bottom surface100bof the contact pin100, it is possible to reduce a diameter of a through-hole that is formed through the lower electrode18to allow the metal terminal18to penetrate therethrough. Further, the contact pin100is formed of a conductive material. Therefore, it is necessary to insulate the contact pin100from the lower electrode18formed of a metal. Accordingly, sleeve101(sleeve111) made of an insulating material is inserted into the through-hole of the lower electrode18. When a diameter of the through-hole is large, a horizontal distance P between the central axis (the axis AX inFIG.2) and an upper end of the sleeve101becomes long. When the distance P becomes long, a circular insulating material with a diameter2P is exposed on an upper surface181of the lower electrode18. At the insulating material portion made of ceramic or the like, it is difficult to perform temperature control such as cooling through the internal flow channel18f. Therefore, the area S2of the bottom surface100bof the contact pin100is decreased to prevent the temperature of the electrostatic chuck20from becoming non-uniform at the upper portion of the through-hole. Accordingly, an area where the insulating material is exposed on the upper surface181of the lower electrode18can be minimized, and the in-plane uniformity of the substrate temperature can be improved.

In particular, a relatively high current of several amperes to 10 amperes instantaneously flows through the bias electrode21due to discharge between the bias electrode21and the generated plasma. During plasma processing, an AC current flows through the bias electrode21and is repeatedly switched ON and OFF depending on the frequency of the RF power LF. A relatively high current instantaneously flows when the AC current is switched from ON to OFF or from OFF to ON. Accordingly, Joule heat is periodically generated and the contact pin300emits heat.

Further, a DC current that is not relatively high compared to the current that flows through the bias electrode21flows through each of the attracting electrode23(the attracting electrodes27aand27b). Therefore, the contact pin100(the contact pin110) according to the present embodiment is preferably used particularly as the power supply terminal of the bias electrode21(the bias electrode25), and is not necessarily used as the power supply terminal of the attracting electrodes23(the attracting electrodes27aand and27b).

The contact pin100(the contact pin110) do not necessarily have a tapered shape. For example, as shown inFIG.4C, each of the contact pins100and110may have a stepped side surface such that the area S1of the upper surface100ais greater than the area S2of the bottom surface100b. By increasing the area S1of the upper surface100aof the contact pin100, it is possible to reduce the electric resistance on the upper surface100aand to suppress the heat emission of the contact pin100. This is also applied to the contact pin110.

Further, as shown inFIG.5, a metal plate104may be disposed between the contact pin100and the metal terminal103. The metal plate104is formed of a conductive material such as aluminum or the like. In this case, the metal plate104is bonded (soldered) to the bottom surface of the contact pin100with a conductive adhesive, and the metal terminal103is pressed against the metal plate104. This is also applied to the contact pin110.

In the contact structure ofFIG.2, the metal terminal103is directly pressed against the bottom surface100bof the contact pin100. Here, the contact resistance increases at the interface between the contact pin100and the metal terminal103. On the other hand, in the contact structure ofFIG.5, the contact pin100and the metal terminal103are brought into contact with each other via the metal plate104. Accordingly, the contact resistance at the contact pin100can be decreased, and the heat emission of the contact pin100can be suppressed.

Next, electrodes embedded in the electrostatic chuck20will be described with reference toFIGS.6A to6C.FIG.6Ashows a VIA-VIA cross section of the electrostatic chuck20shown inFIG.2.FIG.6Bshows a VIB-VIB cross section of the electrostatic chuck20shown inFIG.2.FIG.6Cshows a VIC-VIC cross section of the electrostatic chuck20shown inFIG.2.

Referring to the VIA-VIA cross section ofFIG.6A, the disk-shaped attracting electrode23is disposed in the first region. The attracting electrode23is a film-shaped electrode or a sheet-shaped electrode.

Referring to the VIB-VIB cross section ofFIG.6B, the annular attracting electrodes27aand27bare disposed in the second region. Each of the attracting electrodes27aand27bis a film-shaped electrode or a sheet-shaped electrode. The attracting electrode27bis disposed outside the attracting electrode27a.

Further, the disk-shaped bias electrode21is disposed in the first region. The bias electrode21has a sheet shape or a mesh shape. The bias electrode21is formed of conductive ceramic containing a metal and ceramic used for the electrostatic chuck20.

The material of the bias electrode21may be, but not limited to, conductive ceramic obtained by combining a refractory metal such as tungsten, tantalum, molybdenum, or the like and ceramic used for the electrostatic chuck20. The bias electrode21may have a resistance value lower than or equal to a predetermined value (e.g., 0.1 Ω·cm). The bias electrode21is in contact with the contact pin100at the center thereof.

Referring to the VIC-VIC cross section ofFIG.6C, the annular bias electrode25is disposed in the second region. The bias electrode25is a sheet-shaped electrode or a mesh-shaped electrode. In the bias electrode25, power supply terminals25aare arranged at equal intervals in a circumferential direction. Each of the power supply terminals25ais coupled to the contact pin110. Accordingly, the contact pins110coupled to the bias electrode25are arranged at equal intervals in the circumferential direction of the edge ring26. As a result, the impedance of the RF power LF can become uniform in the circumferential direction, and the variation of the RF power LF in the circumferential direction can be suppressed.

The bias electrode25has a sheet shape or a mesh shape. The bias electrode25is formed of conductive ceramic containing a metal and ceramic used for the electrostatic chuck20.

The bias electrode25has a resistance value lower than or equal to a predetermined value (e.g., 0.1 Ω·cm). The material of the bias electrode25may be, but not limited to, conductive ceramic obtained by combining a refractory metal material such as tungsten, tantalum, molybdenum, or the like and ceramic used for the electrostatic chuck20.

Further, the bias electrode25may be a mesh-shaped metal rather than a sheet-shape metal. In this case, it is possible to reduce the difference in contraction between the bias electrode25and the electrostatic chuck20, which is caused by a difference in linear expansion coefficients between the bias electrode25and the electrostatic chuck20due to heat input from the plasma, and the friction between the bias electrode25and the electrostatic chuck20also can be reduced.

As described above, in accordance with the substrate support14and the plasma processing apparatus1of the present embodiment, the bias electrodes21and25are disposed in the electrostatic chuck20to suppress discharge of the heat transfer gas supplied to the space between the back surface of the substrate W and the upper surface of the electrostatic chuck20.

Further, the contact pin, which electrically couples the electrode for providing the bias power and the power supply line, has a shape in which the area of the surface of the contract pin that is coupled to the electrode is greater than the area of the surface of the contract pin that is coupled to the power supply line. Accordingly, it is possible to suppress heat generated at the contact pin and its vicinity, and to improve the in-plane uniformity of the substrate temperature.

The substrate support and the plasma processing apparatus according to the embodiments of the present disclosure are considered to be illustrative in all respects and not restrictive. The above-described embodiments may be changed or modified in various forms without departing from the scope of the appended claims and the gist thereof. The above-described embodiments may include other configurations without contradicting each other and may be combined without contradicting each other.

The plasma processing apparatus of the present disclosure can be applied to any apparatus using atomic layer deposition (ALD), capacitively coupled plasma (CCP), inductively coupled plasma (ICP), a radial line slot antenna (RLSA), electron cyclotron resonance plasma (ECR), helicon wave plasma (HWP), or the like. Further, the plasma processing apparatus may be any apparatus that performs predetermined processing (e.g., etching, film formation, or the like) on the substrate.