Electrostatic chuck

Abstract

To improve the electrostatic adsorption force of a seal band of an electrostatic chuck to a substrate. [Solution] The electrostatic chuck (1111) includes a ceramic member (1111a) as a dielectric member for supporting a substrate (W), the ceramic member having a first upper surface (200) and an annular seal band (201), the seal band having a second upper surface (252) higher than the first upper surface; a first electrostatic electrode (300) arranged below the first upper surface within the dielectric member; and a second electrostatic electrode (301) arranged below the second upper surface within the dielectric member, electrically connected to the first electrostatic electrode, the first vertical distance (a1) between the first electrostatic electrode and the second upper surface being smaller than the second vertical distance (a2) between the first horizontal plane (P1) including the first upper surface and the second upper surface and being larger than the third vertical distance (a3) between the second horizontal plane (P2) including the first upper surface and the second upper surface, the inner end (322) of the second electrostatic electrode being positioned outside the inner end (250) of the seal band.

Description

[Technical Field]

[0001] SUMMARY OF THE INVENTION An exemplary embodiment of the present disclosure relates to an electrostatic chuck. [Background technology]

[0002] A technique for providing an electrostatic chuck having an annular seal band that supports the outer periphery of a substrate is disclosed in Patent Document 1. The electrostatic chuck electrostatically attracts the substrate at the seal band. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 6124156 Summary of the Invention [Problem to be solved by the invention]

[0004] The present disclosure provides a technique capable of improving the electrostatic adsorption force of a seal band of an electrostatic chuck against a substrate. [Means for solving the problem]

[0005] In one exemplary embodiment of the present disclosure, an electrostatic chuck includes: a dielectric member configured to support a substrate, the dielectric member including a first upper surface and an annular seal band disposed outside the first upper surface, the seal band having a second upper surface higher than the first upper surface; a first electrostatic electrode disposed within the dielectric member below the first upper surface; and a second electrostatic electrode disposed within the dielectric member below the second upper surface and electrically connected to the first electrostatic electrode, wherein a first vertical distance between the second upper surface and the second electrostatic electrode is smaller than a second vertical distance between a first horizontal plane including the first upper surface and the second upper surface and is larger than a third vertical distance between a second horizontal plane including the first upper surface and the second upper surface, and an inner end of the second electrostatic electrode is positioned outer than an inner end of the seal band. [Effects of the Invention]

[0006] According to one exemplary embodiment of the present disclosure, it is possible to provide a technique that can improve the electrostatic adsorption force of a seal band of an electrostatic chuck to a substrate. [Brief explanation of the drawings]

[0007] [Figure 1] FIG. 1 is a diagram illustrating an example of the configuration of a plasma processing system. [Figure 2] FIG. 1 is a diagram illustrating an example of the configuration of a capacitively coupled plasma processing apparatus. [Figure 3] 10A and 10B are diagrams for explaining a configuration example of a substrate support part. [Figure 4] FIG. 2 is a top view of an electrostatic chuck for explaining a configuration example of the electrostatic chuck. [Figure 5] 1A and 1B are diagrams illustrating an example of the configuration of a seal band and an electrostatic electrode of an electrostatic chuck. [Figure 6] 10A and 10B are diagrams illustrating other configuration examples of the seal band and the electrostatic electrode of the electrostatic chuck. [Figure 7] 10A and 10B are diagrams illustrating other configuration examples of the seal band and the electrostatic electrode of the electrostatic chuck. [Figure 8] 10A and 10B are diagrams illustrating other configuration examples of the seal band and the electrostatic electrode of the electrostatic chuck. DETAILED DESCRIPTION OF THE INVENTION

[0008] Hereinafter, each embodiment of the present disclosure will be described.

[0009] In one exemplary embodiment, an electrostatic chuck is provided, comprising: a dielectric member configured to support a substrate, the dielectric member including a first upper surface and an annular seal band disposed outside the first upper surface, the seal band having a second upper surface higher than the first upper surface; a first electrostatic electrode disposed within the dielectric member below the first upper surface; and a second electrostatic electrode disposed within the dielectric member below the second upper surface and electrically connected to the first electrostatic electrode, the second electrostatic electrode configured such that a first vertical distance between the second upper surface and the second electrostatic electrode is smaller than a second vertical distance between a first horizontal plane including the first upper surface and the second upper surface and is larger than a third vertical distance between a second horizontal plane including the first upper surface and the second upper surface, and an inner end of the second electrostatic electrode is located outside the inner end of the seal band.

[0010] In one exemplary embodiment, the dielectric member has a corner formed by connecting the lower end of the inner peripheral wall of the sealing band and the outer end of the first upper surface, and a fourth distance from the corner to the second electrostatic electrode is equal to or greater than a fifth distance from the first upper surface to the first electrostatic electrode.

[0011] In one exemplary embodiment, the fourth distance is greater than or equal to 100 μm.

[0012] In one exemplary embodiment, a sixth distance from the outer peripheral wall of the dielectric member to the second electrostatic electrode is equal to or greater than the fifth distance.

[0013] In one exemplary embodiment, the sixth distance is greater than or equal to 100 μm.

[0014] In one exemplary embodiment, the second electrostatic electrode has a thickness in the vertical direction that is greater than the thickness in the vertical direction of the first electrostatic electrode.

[0015] In one exemplary embodiment, the lower surface of the second electrostatic electrode and the lower surface of the first electrostatic electrode are on the same horizontal plane.

[0016] In one exemplary embodiment, the second electrostatic electrode is positioned higher than the first electrostatic electrode.

[0017] In one exemplary embodiment, the top surface of the second electrostatic electrode is sloped so that it gradually becomes higher from the inner end to the outer end.

[0018] In one exemplary embodiment, the second upper surface slopes from the inner end to the outer end.

[0019] In one exemplary embodiment, the electrostatic sensor further includes a connection electrode that electrically connects the first electrostatic electrode and the second electrostatic electrode.

[0020] In one exemplary embodiment, the electrostatic display device further includes a connection wiring that electrically connects the first electrostatic electrode and the second electrostatic electrode.

[0021] Hereinafter, each embodiment of the present disclosure will be described in detail with reference to the drawings. In each drawing, the same or similar elements are designated by the same reference numerals, and redundant explanations will be omitted. Unless otherwise specified, the positional relationships, such as up, down, left, and right, will be described based on the positional relationships shown in the drawings. The dimensional ratios in the drawings do not represent actual ratios, and the actual ratios are not limited to the ratios shown in the drawings.

[0022] <An example of a plasma processing system> FIG. 1 is a diagram illustrating an exemplary configuration of a plasma processing system. In one embodiment, the plasma processing system includes a plasma processing device 1 and a control unit 2. The plasma processing system is an example of a substrate processing system, and the plasma processing device 1 is an example of a substrate processing device. The plasma processing device 1 includes a plasma processing chamber 10, a substrate support 11, and a plasma generation unit 12. The plasma processing chamber 10 has a plasma processing space. The plasma processing chamber 10 also has at least one gas supply port for supplying at least one processing gas to the plasma processing space and at least one gas exhaust port for exhausting gas from the plasma processing space. The gas supply port is connected to a gas supply unit 20 (described later), and the gas exhaust port is connected to an exhaust system 40 (described later). The substrate support 11 is disposed in the plasma processing space and has a substrate support surface for supporting a substrate.

[0023] The plasma generating unit 12 is configured to generate plasma from at least one processing gas supplied into the plasma processing space. The plasma formed in the plasma processing space may be capacitively coupled plasma (CCP), inductively coupled plasma (ICP), electron cyclotron resonance (ECR) plasma, helicon wave plasma (HWP), or surface wave plasma (SWP). Various types of plasma generating units may be used, including alternating current (AC) plasma generating units and direct current (DC) plasma generating units. In one embodiment, the AC signal (AC power) used in the AC plasma generating unit has a frequency in the range of 100 kHz to 10 GHz. Therefore, the AC signal includes a radio frequency (RF) signal and a microwave signal. In one embodiment, the RF signal has a frequency in the range of 100 kHz to 150 MHz.

[0024] The controller 2 processes computer-executable instructions that cause the plasma processing apparatus 1 to perform the various steps described herein. The controller 2 may be configured to control each element of the plasma processing apparatus 1 to perform the various steps described herein. In one embodiment, part or all of the controller 2 may be included in the plasma processing apparatus 1. The controller 2 may be implemented, for example, by a computer 2a. The controller 2 may include a processing unit 2a1, a memory unit 2a2, and a communication interface 2a3. The functions performed by the processing unit 2a1 described in this disclosure may be implemented in circuitry or processing circuitry, including general-purpose processors, application-specific processors, integrated circuits, application-specific integrated circuits (ASICs), central processing units (CPUs), conventional circuitry, and / or combinations thereof, programmed to perform the described functions. A processor is considered to be a circuit or processing circuit that includes transistors and other circuitry. The processor may be a programmed processor that executes a program stored in the memory unit 2a2. This program may be stored in the storage unit 2a2 in advance or may be acquired via a medium when needed. The acquired program is stored in the storage unit 2a2 and read from the storage unit 2a2 by the processing unit 2a1 for execution. The medium may be various storage media readable by the computer 2a or a communication line connected to the communication interface 2a3. The 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).In this disclosure, a circuit, unit, or means is hardware that is programmed to implement or configured to implement a described function. The hardware may be any hardware described in this disclosure or any hardware that is programmed to implement or known to implement the described function. If the hardware is a processor, which is considered a type of circuit, the circuit, means, or unit is a combination of hardware and software used to configure the hardware and / or processor.

[0025] The following describes a configuration example of a capacitively coupled plasma processing apparatus as an example of the plasma processing apparatus 1. Fig. 2 is a diagram for explaining a configuration example of a capacitively coupled plasma processing apparatus.

[0026] The capacitively coupled plasma processing apparatus 1 includes a plasma processing chamber 10, a gas supply unit 20, a power supply system 30, and an exhaust system 40. The plasma processing apparatus 1 also includes a substrate support 11 and a gas inlet. The gas inlet is configured to introduce at least one process gas into the plasma processing chamber 10. The gas inlet includes a showerhead 13. The substrate support 11 is disposed within the plasma processing chamber 10. The showerhead 13 is disposed above the substrate support 11. In one embodiment, the showerhead 13 forms at least a portion of the ceiling of the plasma processing chamber 10. The plasma processing chamber 10 has a plasma processing space 10s defined by the showerhead 13, a sidewall 10a of the plasma processing chamber 10, and the substrate support 11. The plasma processing chamber 10 is grounded. The showerhead 13 and the substrate support 11 are electrically insulated from the housing of the plasma processing chamber 10.

[0027] The substrate support 11 includes a main body 111 and a ring assembly 112. The main body 111 has a central region 111a for supporting a substrate W and an annular region 111b for supporting the ring assembly 112. A wafer is an example of a substrate W. The annular region 111b of the main body 111 surrounds the central region 111a of the main body 111 in a plan view. The substrate W is disposed on the central region 111a of the main body 111, and the ring assembly 112 is disposed on the annular region 111b of the main body 111 so as to surround the substrate W on the central region 111a of the main body 111. Therefore, the central region 111a is also called a substrate support surface for supporting the substrate W, and the annular region 111b is also called a ring support surface for supporting the ring assembly 112.

[0028] In one embodiment, the main body 111 includes a base 1110 and an electrostatic chuck 1111. The base 1110 includes a conductive member. The conductive member of the base 1110 may function as a lower electrode. The electrostatic chuck 1111 is disposed on the base 1110. The electrostatic chuck 1111 includes a ceramic member 1111a and an electrostatic chuck electrode 1111b disposed within the ceramic member 1111a. The electrostatic chuck electrode 1111b is also referred to as a clamping electrode. In one embodiment, the electrostatic chuck electrode 1111b is electrically connected or coupled to a chuck power supply. The chuck power supply may be a DC power supply or an AC power supply. The ceramic member 1111a has a central region 111a. In one embodiment, the ceramic member 1111a also has an annular region 111b. Note that the annular region 111b may be formed on another member surrounding the electrostatic chuck 1111, such as an annular electrostatic chuck or an annular insulating member. In this case, the ring assembly 112 may be disposed on the annular electrostatic chuck or the annular insulating member, or may be disposed on both the electrostatic chuck 1111 and the annular insulating member. At least one bias electrode electrically connected to or coupled to a power supply 31 and / or a power supply 32 (described later) may be disposed within the ceramic member 1111a. In this case, the at least one bias electrode functions as a lower electrode. Alternatively, the conductive member of the base 1110 and the bias electrode within the ceramic member 1111a may function as multiple lower electrodes. In one embodiment, the first voltage generating unit 32a, which functions as a voltage pulse generating unit (described later), is electrically connected to or coupled to the bias electrode within the ceramic member 1111a, and the first RF generating unit 31a (described later) is electrically connected to or coupled to the conductive member of the base 1110. The electrostatic chuck electrode 1111b may function as a lower electrode. The substrate support 11 therefore comprises at least one bottom electrode.

[0029] The ring assembly 112 includes one or more annular members. In one embodiment, the one or more annular members include one or more edge rings and at least one cover ring. The edge rings are formed of a conductive or insulating material, and the cover rings are formed of an insulating material.

[0030] The substrate support 11 may also include a temperature adjustment module configured to adjust at least one of the electrostatic chuck 1111, the ring assembly 112, and the substrate to a target temperature. The temperature adjustment module may include a heater, a heat transfer medium, a flow passage 1110a, or a combination thereof. A heat transfer fluid such as brine or a gas flows through the flow passage 1110a. In one embodiment, the flow passage 1110a is formed in the base 1110, and one or more heaters are disposed in the ceramic member 1111a of the electrostatic chuck 1111. The substrate support 11 may also include a heat transfer gas supply configured to supply a heat transfer gas to a gap between the backside of the substrate W and the central region 111a.

[0031] The showerhead 13 is configured to introduce at least one processing gas from the gas supply unit 20 into the plasma processing space 10s. The showerhead 13 has at least one gas supply port 13a, at least one gas diffusion chamber 13b, and multiple gas inlets 13c. The processing gas supplied to the gas supply port 13a passes through the gas diffusion chamber 13b and is introduced into the plasma processing space 10s from the multiple gas inlets 13c. The showerhead 13 also includes at least one upper electrode. In addition to the showerhead 13, the gas introduction unit may also include one or more side gas injectors (SGIs) attached to one or more openings formed in the sidewall 10a.

[0032] The gas supply unit 20 may include at least one gas source 21 and at least one flow controller 22. In one embodiment, the gas supply unit 20 is configured to supply at least one process gas from a corresponding gas source 21 to the showerhead 13 via a corresponding flow controller 22. Each flow controller 22 may include, for example, a mass flow controller or a pressure-controlled flow controller. Additionally, the gas supply unit 20 may include at least one flow modulation device that modulates or pulses the flow rate of the at least one process gas.

[0033] The power supply system 30 includes a power supply 31 electrically connected or coupled to the plasma processing chamber 10. In one embodiment, the power supply 31 is electrically connected or coupled to the plasma processing chamber 10 via at least one impedance matcher. The impedance matcher may be a mechanically controlled matcher or an electronically controlled matcher. The power supply 31 is configured to supply at least one RF signal (RF power) to at least one lower electrode and / or at least one upper electrode. This generates plasma from at least one processing gas supplied to the plasma processing space 10s. Therefore, the power supply 31 can function as at least a part of the plasma generation unit 12. Furthermore, by supplying a bias RF signal to at least one lower electrode, a bias potential is generated on the substrate W, thereby attracting ion components in the formed plasma to the substrate W.

[0034] The power supply 31 includes a first RF generating unit 31a and a second RF generating unit 31b. The first RF generating unit 31a is electrically connected or coupled to at least one lower electrode and / or at least one upper electrode and configured to generate a source RF signal (source RF power) to generate plasma in the plasma processing space 10s. In one embodiment, the first RF generating unit 31a is electrically connected or coupled to at least one lower electrode and / or at least one upper electrode via at least one impedance matching box. In one embodiment, the source RF signal has a frequency in the range of 10 MHz to 150 MHz. In one embodiment, the first RF generating unit 31a may be configured to generate multiple source RF signals having different frequencies. The generated one or more source RF signals are supplied to at least one lower electrode and / or at least one upper electrode.

[0035] The second RF generating unit 31b is electrically connected or coupled to at least one lower electrode and configured to generate a bias RF signal (bias RF power). In one embodiment, the second RF generating unit 31b is electrically connected or coupled to at least one lower electrode via at least one impedance matcher. When the first RF generating unit 31a is electrically connected or coupled to a lower electrode, the second RF generating unit 31b may be electrically connected or coupled to the same lower electrode or to another lower electrode. The frequency of the bias RF signal may be the same as or different from the frequency of the source RF signal. In one embodiment, the bias RF signal has a frequency lower than the frequency of the source RF signal. In one embodiment, the bias RF signal has a frequency within a range of 100 kHz to 60 MHz. In one embodiment, the second RF generating unit 31b may be configured to generate multiple bias RF signals having different frequencies. The generated one or more bias RF signals are supplied to at least one lower electrode. In various embodiments, at least one of the source RF signal and the bias RF signal may be pulsed.

[0036] The power supply system 30 may also include a power supply 32 electrically connected or coupled to the plasma processing chamber 10. The power supply 32 includes a first voltage generating unit 32a and a second voltage generating unit 32b. In one embodiment, the first voltage generating unit 32a is electrically connected or coupled to at least one lower electrode and configured to generate a first voltage signal. The generated first voltage signal is applied to the at least one lower electrode. In one embodiment, the second voltage generating unit 32b is electrically connected or coupled to at least one upper electrode and configured to generate a second voltage signal. The generated second voltage signal is applied to the at least one upper electrode.

[0037] In various embodiments, the first and / or second voltage signals may be pulsed. In this case, the first voltage generator 32a and / or the second voltage generator 32b function as a voltage pulse generator configured to generate a sequence of voltage pulses. Thus, the sequence of voltage pulses is applied to at least one lower electrode and / or at least one upper electrode. In one embodiment, the sequence of voltage pulses includes multiple cycles, each cycle including a burst of voltage pulses during a first period and a constant reference voltage during a second period. That is, the bursts of voltage pulses are repeated in the sequence of voltage pulses. The absolute value of the voltage level of the voltage pulses is greater than the absolute value of the voltage level of the reference voltage. The voltage pulses may have an arbitrary waveform, such as a rectangular, trapezoidal, triangular, or combination thereof, and the arbitrary waveform may change over time. The voltage pulses may have either positive or negative polarity. Furthermore, the sequence of voltage pulses may include one or more positive polarity voltage pulses and one or more negative polarity voltage pulses within one cycle. The first and second voltage generating units 32a and 32b may be provided in addition to the power supply 31, or the first voltage generating unit 32a may be provided instead of the second RF generating unit 31b.

[0038] The exhaust system 40 may be connected to, for example, a gas exhaust port 10e provided at the bottom of the plasma processing chamber 10. The exhaust system 40 may include a pressure regulating valve and a vacuum pump. The pressure regulating valve regulates the pressure in the plasma processing space 10s. The vacuum pump may include a turbomolecular pump, a dry pump, or a combination thereof.

[0039] <Example of electrostatic chuck configuration> FIG. 3 is a diagram showing an example of the configuration of an electrostatic chuck 1111 in this exemplary embodiment. In one embodiment, the electrostatic chuck 1111 has a ceramic member 1111a as a dielectric member and an electrostatic chuck electrode 1111b. The dielectric member may be made of alumina, aluminum nitride, polyimide, or the like. The electrostatic chuck 1111 may be capable of electrostatically attracting a substrate having a diameter of 300 mm. The electrostatic chuck electrode 1111b may be made of a metal or alloy containing at least one selected from the group consisting of tungsten, molybdenum, and titanium.

[0040] In one embodiment, the ceramic member 1111 a has a first upper surface 200 and an annular seal band 201 disposed on the outside of the first upper surface 200 .

[0041] In one embodiment, the first upper surface 200 has a gas outlet 210 through which a heat transfer gas flows out. In one embodiment, the gas outlet 210 is connected to a heat transfer gas supply unit 212 through a gas passage 211. The gas passage 211 may pass through the inside of the substrate support 11. The heat transfer gas supply unit 212 may be provided outside the chamber 10. As shown in FIG. 4, the first upper surface 200 has a circular shape with its center at the center of the ceramic member 1111a. The gas outlet 210 is disposed at the center of the first upper surface 200. One or more gas outlets 210 may be disposed. The heat transfer gas may include helium gas.

[0042] In one embodiment, a plurality of protrusions 220 are arranged on the first upper surface 200. As shown in FIG. 3, the protrusions 220 protrude upward relative to the first upper surface 200. The protrusions 220 may have a cylindrical shape. The protrusions 220 have a flat upper surface 221. The height of the protrusions 220 relative to the first upper surface 200 may be 5 μm or more and 50 μm or less. In one embodiment, as shown in FIG. 4, the plurality of protrusions 220 may be arranged at equal intervals along the circumferential direction around the center of the first upper surface 200. The plurality of protrusions 220 may be arranged concentrically or radially relative to the center of the first upper surface 200.

[0043] 3 and 4, the seal band 201 is an annular protrusion that protrudes upward from the first upper surface 200. The seal band 201 is arranged in the shape of a ring with its center at the center of the ceramic member 1111a.

[0044] As shown in FIG. 5 , the seal band 201 has an inner circumferential wall 250, an outer circumferential wall 251, and a second upper surface 252. In one embodiment, the inner circumferential wall 250 and the outer circumferential wall 251 are annular vertical surfaces. The second upper surface 252 is annular horizontal surfaces. The second upper surface 252 connects the upper ends of the inner circumferential wall 250 and the outer circumferential wall 251. The second upper surface 252 may be positioned at the same level as or higher than the upper surface 221 of the protrusion 220. A right-angled corner 254 is formed by connecting the lower end of the inner circumferential wall 250 and the outer end of the first upper surface 200.

[0045] The width D1 (length from the inner peripheral edge to the outer peripheral edge of seal band 201) of second upper surface 252 in the radial direction (X direction shown in FIGS. 4 and 5) may be 0.3 mm or more and 4 mm or less. The height H1 of seal band 201 may be 5 μm or more and 50 μm or less.

[0046] The seal band 201 may be formed integrally with other portions of the ceramic member 1111a, including the first upper surface 200, or may be formed separately.

[0047] As shown in FIG. 3, the electrostatic chuck electrode 1111b includes a first electrostatic electrode 300 disposed below the first upper surface 200 inside the ceramic member 1111a, and a second electrostatic electrode 301 disposed below the second upper surface 252.

[0048] In one embodiment, the first electrostatic electrode 300 and the second electrostatic electrode 301 are integrally formed and electrically connected to each other.

[0049] As shown in FIG. 4, the first electrostatic electrode 300 has a circular shape having the same center as the first upper surface 200. As shown in FIG. 3, the first electrostatic electrode 300 has a thin plate shape and is arranged horizontally. As shown in FIG. 5, the first electrostatic electrode 300 has an outer diameter larger than that of the first upper surface 200. The first electrostatic electrode 300 may have a thickness T1 in the vertical direction (Z direction shown in FIG. 5) of 5 μm or more and 100 μm or less. The outer end of the first electrostatic electrode 300 is located outside the inner end of the seal band 201 and is connected to the inner end of the second electrostatic electrode 301. The first electrostatic electrode 300 has a first electrode upper surface 310 and a first electrode lower surface 311.

[0050] As shown in FIG. 4, the second electrostatic electrode 301 has an annular shape having the same center as the second upper surface 252. As shown in FIG. 5, the second electrostatic electrode 301 has a rectangular cross-sectional shape with thickness in the vertical and horizontal directions. The second electrostatic electrode 301 has a thickness T2 larger than that of the first electrostatic electrode 300 in the vertical direction. The thickness T2 may be 5 μm or more and 650 μm or less. The second electrostatic electrode 301 has a shape protruding upward with respect to the first electrostatic electrode 300.

[0051] In one embodiment, the second electrostatic electrode 301 has a second electrode upper surface 320, a second electrode lower surface 321, an inner surface 322, and an outer surface 323. The second electrode upper surface 320 and the second electrode lower surface 321 are flat horizontal planes, and the inner surface 322 and the outer surface 323 are vertical planes. The second electrode lower surface 321 may be arranged at the same height as the first electrode lower surface 311 of the first electrostatic electrode 300. The second electrode upper surface 320 is arranged at a position higher than the first electrode upper surface 310 of the first electrostatic electrode 300.

[0052] The first distance a1 in the vertical direction between the second upper surface 252 and the second electrostatic electrode 301 (second electrode upper surface 320) is smaller than the second distance a2 in the vertical direction between the first horizontal plane P1 including the first electrostatic electrode 300 (first electrode upper surface 310) and the second upper surface 252 (a1 < a2). That is, the second electrostatic electrode 301 is configured such that the distance to the substrate W placed on the ceramic member 1111a is shorter than that of the first electrostatic electrode 300.

[0053] The first distance a1 is greater than a third distance a3 (a1>a3) in the vertical direction between the second horizontal plane P2 including the first upper surface 200 and the second upper surface 252. That is, the second electrostatic electrode 301 is disposed below the seal band 201, not inside the seal band 201.

[0054] The inner end (inner surface 322) of the second electrostatic electrode 301 is located radially outward from the inner end (inner circumferential wall 250) of the seal band 201.

[0055] A fourth distance a4 from the corner 254 to the second electrostatic electrode 301 is equal to or greater than a fifth distance a5 from the first upper surface 200 to the first electrostatic electrode 300 (a4≧a5). That is, the second electrostatic electrode 301 is sufficiently separated from the space E1 formed by the substrate W, the seal band 201, and the first upper surface 200. The fourth distance a4 may be 100 μm or greater. A sixth distance a6 from the outer peripheral wall 1111c of the ceramic member 1111a to the second electrostatic electrode 301 (outer surface 323) is equal to or greater than the fifth distance a5 (a6≧a5). The sixth distance a6 may be 100 μm or greater.

[0056] 3, the first electrostatic electrode 300 and the second electrostatic electrode 301 are electrically connected to a single direct current (DC) power supply 351 via a switch 350. When a DC voltage is applied to the first electrostatic electrode 300 and the second electrostatic electrode 301 by the DC power supply 351, an electrostatic attractive force (Coulomb force) can be generated between the ceramic member 1111a and the substrate W. The substrate W is attracted to the ceramic member 1111a by the electrostatic attractive force and is adsorbed and held on the upper surface of the ceramic member 1111a.

[0057] <Example of substrate processing> Plasma processing of a substrate is performed in the plasma processing apparatus 1. The plasma processing includes etching processing in which a film on the substrate W is etched using plasma. The plasma processing is performed by a control unit 2 in the plasma processing apparatus 1.

[0058] First, the substrate W is carried into the chamber 10, and as shown in Fig. 3, the substrate W is placed on the ceramic member 1111a of the electrostatic chuck 1111. The substrate W is supported by the seal band 201 and the protrusion 220. Then, a DC voltage is applied to the electrostatic chuck electrode 1111b (the first electrostatic electrode 300 and the second electrostatic electrode 301) by the DC power supply 351, which generates an electrostatic attraction between the ceramic member 1111a and the substrate W, causing the substrate W to be electrostatically attracted to the seal band 201 of the electrostatic chuck 1111.

[0059] A heat transfer medium is supplied to the flow path 1110a of the temperature adjustment module, and the temperature of the substrate W on the electrostatic chuck 1111 is adjusted to a given temperature. The heat of the substrate W is transferred from the seal band 201 to the heat transfer medium via the ceramic member 1111a and the base 1110.

[0060] A heat transfer gas is supplied from the heat transfer gas supply unit 212 to the gas outlet unit 210, and the heat transfer gas is supplied from the gas outlet unit 210 to the space E1 formed between the substrate W and the first upper surface 200. The seal band 201 seals the space E1 between the first upper surface 200 and the substrate W so that the heat transfer gas filled therein does not leak into the plasma processing space 10s. The heat transfer gas adjusts the temperature of the substrate W from its back surface side.

[0061] 2 to the shower head 13, and then supplied to the plasma processing space 10s from the shower head 13. The processing gas supplied at this time includes a gas that generates active species necessary for etching the substrate W.

[0062] One or more RF signals are supplied to the upper electrode and / or the lower electrode from the RF power supply 31. The atmosphere in the plasma processing space 10s is exhausted through the gas exhaust port 10e, and the pressure inside the plasma processing space 10s is reduced. Plasma is generated on the substrate support 11 in the plasma processing space 10s, and the substrate W is etched.

[0063] According to this exemplary embodiment, the electrostatic chuck 1111 includes a ceramic member 1111a including a first upper surface 200 and an annular seal band 201, a first electrostatic electrode 300 disposed within the ceramic member 1111a below the first upper surface 200, and a second electrostatic electrode 301 disposed within the ceramic member 1111a below a second upper surface 252 of the seal band 201 and electrically connected to the first electrostatic electrode 300. The second electrostatic electrode 301 is configured such that a first distance a1 in the vertical direction between the second upper surface 252 and the second electrostatic electrode 301 is smaller than a second distance a2 in the vertical direction between a first horizontal plane P1 including the first electrostatic electrode 300 and the second upper surface 252 and is larger than a third distance a3 in the vertical direction between a second horizontal plane P2 including the first upper surface 200 and the second upper surface 252, and an inner end of the second electrostatic electrode 301 is positioned outward from an inner end of the seal band 201. Because the first distance a1 is smaller than the second distance a2, the distance between the second electrostatic electrode 301 and the substrate is shorter than the distance between the first electrostatic electrode 300 and the substrate, thereby improving the electrostatic adsorption force of the seal band 201 of the electrostatic chuck 1111 with respect to the substrate. As a result, heat from the outer periphery of the substrate is more easily transferred to the ceramic member 1111a through the seal band 201, making it easier to regulate the temperature of the outer periphery of the substrate. Furthermore, because the first distance a1 is larger than the third distance a3 and the inner end of the second electrostatic electrode 301 is positioned outward from the inner end of the seal band 201, insulation between the second electrostatic electrode 301 and the periphery of the seal band 201 is ensured. Furthermore, because the first electrostatic electrode 300 and the second electrostatic electrode 301 are electrically connected, power can be supplied to the first electrostatic electrode 300 and the second electrostatic electrode 301 using a single power source.

[0064] In this exemplary embodiment, the fourth distance a4 from the corner 254 to the second electrostatic electrode 301 is equal to or greater than the fifth distance a5 from the first upper surface 200 to the first electrostatic electrode 300. This makes it possible to suppress abnormal discharge occurring between the second electrostatic electrode 301 and the corner 254.

[0065] In this exemplary embodiment, the sixth distance a6 from the outer peripheral wall 1111c of the ceramic member 1111a to the second electrostatic electrode 301 is equal to or greater than the fifth distance a5, thereby ensuring insulation between the second electrostatic electrode 301 and the outside of the ceramic member 1111a.

[0066] In this exemplary embodiment, the second electrostatic electrode 301 has a thickness in the vertical direction that is greater than that of the first electrostatic electrode 300. This makes it easier to form the second electrostatic electrode 301. In addition, the second electrostatic electrode 301 has high thermal conductivity, which makes it easier to transfer heat from the outer periphery of the substrate to the ceramic member 1111a through the seal band 201.

[0067] The second electrostatic electrode 301 may have other configurations. As shown in FIG. 6 , the second electrostatic electrode 301 may be positioned higher than the first electrostatic electrode 300. In one embodiment, the second electrostatic electrode 301 may have a thin thickness T3 in the vertical direction. The thickness T3 may be approximately the same as the thickness T1 of the first electrostatic electrode 300. The thickness T3 may be 5 μm or more and 100 μm or less. The second electrode lower surface 321 of the second electrostatic electrode 301 is positioned higher than the first electrode lower surface 311 and the first electrode upper surface 310 of the first electrostatic electrode 300. The first electrostatic electrode 300 and the second electrostatic electrode 301 are connected by a connection electrode 400. The connection electrode 400 may be annular. The connection electrode 400 may extend in the vertical direction. The connecting electrode 400 may have a first connecting end 410 connected to the outer end of the first electrostatic electrode 300 and a second connecting end 411 connected to the inner end of the second electrostatic electrode 301. The first electrostatic electrode 300, the second electrostatic electrode 301 and the connecting electrode 400 may be integrally formed.

[0068] 7, the first electrostatic electrode 300 and the second electrostatic electrode 301 may be connected by a connection wiring 450. The connection wiring 450 has a first connection end 460 connected to the first electrode lower surface 311 of the first electrostatic electrode 300 and a second connection end 461 connected to the second electrode lower surface 321 of the second electrostatic electrode 301. A plurality of connection wirings 450 may be arranged. The first electrostatic electrode 300, the second electrostatic electrode 301, and the connection wiring 450 may be formed separately. The connection wiring 450 can be routed through the inside of the ceramic member 1111a or the outside below the ceramic member 1111a.

[0069] As shown in FIG. 8 , the second electrode upper surface 320 of the second electrostatic electrode 301 may be inclined so that it becomes higher from the inner edge to the outer edge. The second upper surface 252 of the seal band 201 may be inclined so that it becomes higher from the inner edge to the outer edge, similar to the second electrode upper surface 320. The second electrode upper surface 320 and the second upper surface 252 may be inclined at the same angle with respect to the horizontal plane. The first electrostatic electrode 300 and the second electrostatic electrode 301 may be connected by a connection wiring 450. The first distance a1 is the shortest distance in the vertical direction between the second upper surface 252 and the second electrode upper surface 320. The second distance a2 is the shortest distance in the vertical direction between the first horizontal plane P1 of the first electrostatic electrode 300 and the second upper surface 252. The third distance a3 is the shortest distance in the vertical direction between the second upper surface 252 and the second horizontal plane P2 of the first upper surface 200.

[0070] In the above embodiment, the electrostatic chuck 1111 is used in a capacitively coupled plasma apparatus, but the present invention is not limited to this and may be used in other types of plasma apparatus. Furthermore, the electrostatic chuck 1111 is not limited to plasma processing apparatuses and may be used in other substrate processing apparatuses.

[0071] Embodiments of the present disclosure further include the following aspects.

[0072] (Appendix 1) a dielectric member configured to support a substrate, the dielectric member including a first upper surface and an annular seal band disposed outside the first upper surface, the seal band having a second upper surface higher than the first upper surface; a first electrostatic electrode disposed within the dielectric member below the first upper surface; a second electrostatic electrode disposed below the second upper surface within the dielectric member and electrically connected to the first electrostatic electrode, wherein a first distance in the vertical direction between the second upper surface and the second electrostatic electrode is smaller than a second distance in the vertical direction between a first horizontal plane including the first electrostatic electrode and the second upper surface and is larger than a third distance in the vertical direction between a second horizontal plane including the first upper surface and the second upper surface, and an inner end of the second electrostatic electrode is positioned outer than an inner end of the seal band; Electrostatic chuck.

[0073] (Appendix 2) the dielectric member has a corner portion formed by connecting a lower end of an inner circumferential wall of the seal band and an outer end of the first upper surface, a fourth distance from the corner to the second electrostatic electrode is equal to or greater than a fifth distance from the first upper surface to the first electrostatic electrode; 2. The electrostatic chuck of claim 1.

[0074] (Appendix 3) The fourth distance is 100 μm or more. 3. The electrostatic chuck of claim 2.

[0075] (Appendix 4) a sixth distance from the outer peripheral wall of the dielectric member to the second electrostatic electrode is equal to or greater than the fifth distance; 3. The electrostatic chuck of claim 2.

[0076] (Appendix 5) The sixth distance is 100 μm or more. 5. The electrostatic chuck of claim 4.

[0077] (Appendix 6) The thickness of the second electrostatic electrode in the vertical direction is greater than the thickness of the first electrostatic electrode in the vertical direction. 6. The electrostatic chuck of claim 1.

[0078] (Appendix 7) a lower surface of the second electrostatic electrode and a lower surface of the first electrostatic electrode are on the same horizontal plane; 7. The electrostatic chuck of claim 6.

[0079] (Appendix 8) The second electrostatic electrode is disposed at a higher position than the first electrostatic electrode. 6. The electrostatic chuck of claim 1.

[0080] (Appendix 9) The upper surface of the second electrostatic electrode is inclined so as to gradually become higher from the inner end toward the outer end. 9. The electrostatic chuck of claim 1.

[0081] (Appendix 10) The second upper surface is inclined so as to gradually increase in height from the inner end toward the outer end. 10. The electrostatic chuck of claim 1.

[0082] (Appendix 11) further comprising a connection electrode that electrically connects the first electrostatic electrode and the second electrostatic electrode; 11. The electrostatic chuck of claim 1.

[0083] (Appendix 12) further comprising a connection wiring that electrically connects the first electrostatic electrode and the second electrostatic electrode; 11. The electrostatic chuck of claim 1.

[0084] The above embodiments are described for the purpose of explanation and are not intended to limit the scope of the present disclosure. Various modifications can be made to the above embodiments without departing from the scope and spirit of the present disclosure. For example, some components in one embodiment can be added to other embodiments. Also, some components in one embodiment can be replaced with corresponding components in other embodiments. [Explanation of symbols]

[0085] 1...plasma processing apparatus, 10...chamber, 11...substrate support, 1111...electrostatic chuck, 1111a...ceramic member, 1111b...electrostatic chuck electrode, 200...first upper surface, 201...seal band, 252...second upper surface, 300...first electrostatic electrode, 301...second electrostatic electrode, a1...first distance, a2...second distance, a3...third distance, a4...fourth distance, a5...fifth distance, a6...sixth distance, P1...first horizontal surface, P2...second horizontal surface, W...substrate

Claims

1. a dielectric member configured to support a substrate, the dielectric member including a first upper surface and an annular seal band disposed on an outer periphery of the first upper surface, the seal band having a second upper surface higher than the first upper surface; a first electrostatic electrode having a constant height and disposed below the first upper surface within the dielectric member; a second electrostatic electrode disposed below the second upper surface within the dielectric member and at a position lower than the first upper surface, and electrically connected to the first electrostatic electrode, wherein a first distance in the vertical direction between the second upper surface and the second electrostatic electrode is smaller than a second distance in the vertical direction between a first horizontal plane including the first electrostatic electrode and the second upper surface and is larger than a third distance in the vertical direction between a second horizontal plane including the first upper surface and the second upper surface, and an inner end of the second electrostatic electrode is positioned outer than an inner end of the seal band; Electrostatic chuck.

2. the dielectric member has a corner portion formed by connecting a lower end of an inner circumferential wall of the seal band and an outer end of the first upper surface, a fourth distance from the corner to the second electrostatic electrode is equal to or greater than a fifth distance from the first upper surface to the first electrostatic electrode; 10. The electrostatic chuck of claim 1.

3. The fourth distance is 100 μm or more.

3. The electrostatic chuck of claim 2.

4. a sixth distance from the outer peripheral wall of the dielectric member to the second electrostatic electrode is equal to or greater than the fifth distance; 3. The electrostatic chuck of claim 2.

5. The sixth distance is 100 μm or more.

5. The electrostatic chuck of claim 4.

6. The thickness of the second electrostatic electrode in the vertical direction is greater than the thickness of the first electrostatic electrode in the vertical direction.

10. The electrostatic chuck of claim 1.

7. a lower surface of the second electrostatic electrode and a lower surface of the first electrostatic electrode are on the same horizontal plane; 7. The electrostatic chuck of claim 6.

8. The second electrostatic electrode is disposed at a higher position than the first electrostatic electrode.

10. The electrostatic chuck of claim 1.

9. The upper surface of the second electrostatic electrode is inclined so as to gradually become higher from the inner end toward the outer end.

10. The electrostatic chuck of claim 1.

10. The second upper surface is inclined so as to gradually increase in height from the inner end toward the outer end.

10. The electrostatic chuck of claim 9.

11. further comprising a connection electrode that electrically connects the first electrostatic electrode and the second electrostatic electrode; 10. The electrostatic chuck of claim 1.

12. further comprising a connection wiring that electrically connects the first electrostatic electrode and the second electrostatic electrode; 10. The electrostatic chuck of claim 1.

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