electrostatic chuck

Abstract

To improve the electrostatic attraction force to the substrate in the sealing band of an electrostatic chuck. [Solution] The electrostatic chuck 1111 includes a ceramic member 1111a as a dielectric member that supports a substrate W and includes a first upper surface 200 and an annular seal band 201, the seal band having a second upper surface 252 that is higher than the first upper surface; a first electrostatic electrode 300 disposed below the first upper surface within the dielectric member; and a second electrostatic electrode 301 disposed below the second upper surface within the dielectric member and electrically connected to the first electrostatic electrode, wherein a first vertical distance a1 between the second upper surface and the second upper surface is smaller than a second vertical distance a2 between the first horizontal plane P1 including the first electrostatic electrode and the second upper surface, and is larger than a third vertical distance a3 between the second horizontal plane P2 including the first upper surface and the second upper surface, and the inner end 322 of the second electrostatic electrode is located outside the inner end 250 of the seal band.

Description

Technical Field

[0001] Exemplary embodiments of the present disclosure relate to electrostatic chucks.

Background Art

[0002] As a technology for providing an electrostatic chuck having an annular seal band that supports the outer peripheral portion of a substrate, there is a technology described in Patent Document 1. The electrostatic chuck electrostatically adsorbs the substrate at the seal band.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] The present disclosure provides a technology capable of improving the electrostatic adsorption force on a substrate in a seal band of an electrostatic chuck.

Means for Solving the Problems

[0005] An exemplary embodiment of the present disclosure provides an electrostatic chuck, comprising a dielectric member configured to support a substrate, the dielectric member comprising a first upper surface and an annular sealing band disposed outside the first upper surface, the sealing band having a second upper surface higher than the first upper surface, a first electrostatic electrode disposed below the first upper surface within the dielectric member, and a second electrostatic electrode disposed below the second upper surface within the dielectric member 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 less than a second vertical distance between a first horizontal plane containing the first electrostatic electrode and the second upper surface, and greater than a third vertical distance between the second horizontal plane containing the first upper surface and the second upper surface, and the inner end of the second electrostatic electrode is located outside the inner end of the sealing band. [Effects of the Invention]

[0006] According to one exemplary embodiment of the present disclosure, a technique can be provided that can improve the electrostatic attraction force of the sealing band of an electrostatic chuck to a substrate. [Brief explanation of the drawing]

[0007] [Figure 1] This is a diagram illustrating an example configuration of a plasma processing system. [Figure 2] This is a diagram illustrating an example configuration of a capacitively coupled plasma processing apparatus. [Figure 3] This is a diagram illustrating an example of the configuration of the substrate support section. [Figure 4] This is a top view of an electrostatic chuck to illustrate an example of its configuration. [Figure 5] This diagram illustrates an example configuration of a sealing band and electrostatic electrode for an electrostatic chuck. [Figure 6] This diagram illustrates other configuration examples of the sealing band and electrostatic electrode of an electrostatic chuck. [Figure 7] This diagram illustrates other configuration examples of the sealing band and electrostatic electrode of an electrostatic chuck. [Figure 8] This diagram illustrates other configuration examples of the sealing band and electrostatic electrode of an electrostatic chuck. [Modes for carrying out the invention]

[0008] The embodiments of this disclosure are described below.

[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 sealing band disposed outside the first upper surface, the sealing band having a second upper surface higher than the first upper surface; a first electrostatic electrode disposed below the first upper surface within the dielectric member; and a second electrostatic electrode disposed below the second upper surface within the dielectric member and electrically connected to the first electrostatic electrode, wherein the second electrostatic electrode is configured such that a first vertical distance between the second upper surface and the second electrostatic electrode is less than a second vertical distance between a first horizontal plane containing the first electrostatic electrode and the second upper surface, and greater than a third vertical distance between the second horizontal plane containing the first upper surface and the second upper surface, and the inner end of the second electrostatic electrode is located outside the inner end of the sealing band.

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

[0011] In one exemplary embodiment, the fourth distance is 100 μm or more.

[0012] In one exemplary embodiment, the 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 100 μm or more.

[0014] In one exemplary embodiment, the vertical thickness of the second electrostatic electrode is greater than the vertical thickness 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 disposed at a position higher than the first electrostatic electrode.

[0017] In one exemplary embodiment, the upper surface of the second electrostatic electrode is inclined so as to gradually increase from the inner end to the outer end.

[0018] In one exemplary embodiment, the second upper surface is inclined so as to gradually increase from the inner end to the outer end.

[0019] In one exemplary embodiment, it further includes a connection electrode for electrically connecting the first electrostatic electrode and the second electrostatic electrode.

[0020] In one exemplary embodiment, it further includes a connection wiring for electrically connecting 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 the drawings, the same or similar elements are denoted by the same reference numerals, and redundant descriptions are omitted. Unless otherwise specified, the positional relationships such as up, down, left, and right are 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.

[0022] <An example of a plasma processing system> Figure 1 is a diagram illustrating an example configuration of a plasma processing system. In one embodiment, the plasma processing system includes a plasma processing apparatus 1 and a control unit 2. The plasma processing system is an example of a substrate processing system, and the plasma processing apparatus 1 is an example of a substrate processing apparatus. The plasma processing apparatus 1 includes a plasma processing chamber 10, a substrate support unit 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 outlet for discharging 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 outlet is connected to an exhaust system 40, which will be described later. The substrate support unit 11 is located in the plasma processing space and has a substrate support surface for supporting a substrate.

[0023] The plasma generation 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 (ECR) plasma, a helicon wave excited plasma (HWP), or a surface wave plasma (SWP), etc. Various types of plasma generation units, including an AC (alternating current) plasma generation unit and a DC (direct current) plasma generation unit, may also be used. In one embodiment, the AC signal (AC power) used in the AC plasma generation unit has a frequency in the range of 100 kHz to 10 GHz. Therefore, the AC signal includes an RF (radio frequency) 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 control unit 2 processes computer-executable instructions that cause the plasma processing apparatus 1 to perform the various processes described herein. The control unit 2 may be configured to control each element of the plasma processing apparatus 1 to perform the various processes described herein. In one embodiment, some or all of the control unit 2 may be included in the plasma processing apparatus 1. The control unit 2 is implemented, for example, by a computer 2a. The control unit 2 may include a processing unit 2a1, a storage unit 2a2, and a communication interface 2a3. The functions implemented by the processing unit 2a1 described herein may be implemented in a circuit or processing circuitry, including a general-purpose processor, an application-specific processor, integrated circuits, ASICs (Application Specific Integrated Circuits), a CPU (Central Processing Unit), conventional circuitry, and / or a combination thereof, programmed to implement the functions described herein. A processor is considered a circuit or processing circuit, including transistors and other circuitry. A processor may be a programmed processor that executes a program stored in the storage unit 2a2. This program may be stored in the memory unit 2a2 in advance, or it may be retrieved via a medium when needed. The retrieved program is stored in the memory unit 2a2 and read from the memory unit 2a2 and executed by the processing unit 2a1. The medium may be various storage media readable by the computer 2a, or it may be a communication line connected to the communication interface 2a3. The memory unit 2a2 may include RAM (Random Access Memory), ROM (Read Only Memory), HDD (Hard Disk Drive), SSD (Solid State Drive), or a combination thereof. The communication interface 2a3 may communicate with the plasma processing device 1 via a communication line such as a LAN (Local Area Network).In this disclosure, circuits, units, and means are hardware programmed to perform or configured to perform the functions described. Such hardware may be any hardware described in this disclosure, or any hardware known to be programmed to perform or execute the functions described. If such hardware is a processor that is considered to be a type of circuit, such circuit, means, or unit is a combination of hardware and software used to constitute such hardware and / or processor.

[0025] The following describes an example configuration of a capacitively coupled plasma processing apparatus as an example of plasma processing apparatus 1. Figure 2 is a diagram illustrating an example configuration 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 unit 11 and a gas introduction unit. The gas introduction unit is configured to introduce at least one processing gas into the plasma processing chamber 10. The gas introduction unit includes a shower head 13. The substrate support unit 11 is located inside the plasma processing chamber 10. The shower head 13 is located above the substrate support unit 11. In one embodiment, the shower head 13 constitutes 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 shower head 13, the side walls 10a of the plasma processing chamber 10, and the substrate support unit 11. The plasma processing chamber 10 is grounded. The shower head 13 and the substrate support unit 11 are electrically insulated from the housing of the plasma processing chamber 10.

[0027] The substrate support portion 11 includes a main body portion 111 and a ring assembly 112. The main body portion 111 has a central region 111a for supporting the substrate W and an annular region 111b for supporting the ring assembly 112. A wafer is an example of the substrate W. The annular region 111b of the main body portion 111 surrounds the central region 111a of the main body portion 111 in a plan view. The substrate W is placed on the central region 111a of the main body portion 111, and the ring assembly 112 is placed on the annular region 111b of the main body portion 111 so as to surround the substrate W on the central region 111a of the main body portion 111. Therefore, the central region 111a is also called the substrate support surface for supporting the substrate W, and the annular region 111b is also called the 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 can function as a lower electrode. The electrostatic chuck 1111 is placed on the base 1110. The electrostatic chuck 1111 includes a ceramic member 1111a and an electrostatic chuck electrode 1111b placed within the ceramic member 1111a. The electrostatic chuck electrode 1111b is also called 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. Furthermore, other members surrounding the electrostatic chuck 1111, such as an annular electrostatic chuck or an annular insulating member, may have an annular region 111b. In this case, the ring assembly 112 may be placed on the annular electrostatic chuck or the annular insulating member, or on both the electrostatic chuck 1111 and the annular insulating member. In addition, at least one bias electrode, electrically connected or coupled to the power supply 31 and / or power supply 32 described later, may be placed within the ceramic member 1111a. In this case, at least one bias electrode functions as a lower electrode. Also, the conductive member of the base 1110 and the bias electrode in the ceramic member 1111a may function as multiple lower electrodes. In one embodiment, the first voltage generation unit 32a, which functions as a voltage pulse generation unit described later, is electrically connected or coupled to the bias electrode in the ceramic member 1111a, and the first RF generation unit 31a, described later, is electrically connected or coupled to the conductive member of the base 1110. Furthermore, the electrostatic chuck electrode 1111b may function as a lower electrode. Therefore, the substrate support portion 11 includes at least one lower 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 covering ring. The edge rings are formed of a conductive or insulating material, and the covering rings are formed of an insulating material.

[0030] The substrate support section 11 may also include a temperature control 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 control module may include a heater, a heat transfer medium, a flow path 1110a, or a combination thereof. A heat transfer fluid, such as brine or gas, flows through the flow path 1110a. In one embodiment, the flow path 1110a is formed within the base 1110, and one or more heaters are arranged within the ceramic member 1111a of the electrostatic chuck 1111. The substrate support section 11 may also include a heat transfer gas supply section configured to supply heat transfer gas to the gap between the back surface 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 a plurality of gas inlet ports 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 through the plurality of gas inlet ports 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 side wall 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 processing gas to the shower head 13 from a corresponding gas source 21 via a corresponding flow controller 22. Each flow controller 22 may include, for example, a mass flow controller or a pressure-controlled flow controller. Furthermore, the gas supply unit 20 may include at least one flow modulation device that modulates or pulses the flow rate of at least one processing gas.

[0033] The power supply system 30 includes a power supply 31 that is electrically connected to or coupled to the plasma processing chamber 10. In one embodiment, the power supply 31 is electrically connected to 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. Thus, the power supply 31 can function as at least part of the plasma generation unit 12. In addition, by supplying a bias RF signal to at least one lower electrode, a bias potential is generated on the substrate W, and ionic components in the formed plasma can be drawn into the substrate W.

[0034] The power supply 31 includes a first RF generation unit 31a and a second RF generation unit 31b. The first RF generation unit 31a is electrically connected or coupled to at least one lower electrode and / or at least one upper electrode and is 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 generation 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 matcher. 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 generation 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 supplied to at least one lower electrode and / or at least one upper electrode.

[0035] The second RF generation unit 31b is electrically connected to or coupled to at least one lower electrode and is configured to generate a bias RF signal (bias RF power). In one embodiment, the second RF generation unit 31b is electrically connected to or coupled to at least one lower electrode via at least one impedance matcher. If the first RF generation unit 31a is electrically connected to or coupled to a lower electrode, the second RF generation unit 31b may be electrically connected to or coupled to the same lower electrode, or it may be electrically connected to or coupled to a different 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 lower frequency than the frequency of the source RF signal. In one embodiment, the bias RF signal has a frequency in the range of 100 kHz to 60 MHz. In one embodiment, the second RF generation unit 31b may be configured to generate a plurality of 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 that is electrically connected to or coupled to the plasma processing chamber 10. The power supply 32 includes a first voltage generation unit 32a and a second voltage generation unit 32b. In one embodiment, the first voltage generation unit 32a is electrically connected to or coupled to at least one lower electrode and configured to generate a first voltage signal. The generated first voltage signal is applied to at least one lower electrode. In one embodiment, the second voltage generation unit 32b is electrically connected to or coupled to at least one upper electrode and configured to generate a second voltage signal. The generated second voltage signal is applied to 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 generation unit 32a and / or the second voltage generation unit 32b function as voltage pulse generation units 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 has multiple cycles, each cycle including a burst of voltage pulses in a first period and a constant reference voltage in a second period. That is, in the sequence of voltage pulses, bursts of voltage pulses are repeated. The absolute value of the voltage level of the voltage pulse is greater than the absolute value of the voltage level of the reference voltage. The voltage pulse may have an arbitrary waveform having a rectangular, trapezoidal, triangular, or a combination thereof, and the arbitrary waveform may change over time. The voltage pulse may have positive polarity or negative polarity. The sequence of voltage pulses may also include one or more positive voltage pulses and one or more negative voltage pulses within one cycle. The first and second voltage generation units 32a and 32b may be provided in addition to the power supply 31, and the first voltage generation unit 32a may be provided in place of the second RF generation unit 31b.

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

[0039] <Example configuration of an electrostatic chuck> Figure 3 shows an example of the configuration of the 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 material of the dielectric member may be alumina, aluminum nitride, or polyimide. The electrostatic chuck 1111 may electrostatically attract a substrate with a diameter of 300 mm. The material of the electrostatic chuck electrode 1111b may be 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 1111a has a first upper surface 200 and an annular sealing band 201 positioned outside the first upper surface 200.

[0041] In one embodiment, the first upper surface 200 has a gas outlet section 210 through which heat transfer gas flows. In one embodiment, the gas outlet section 210 is connected to a heat transfer gas supply section 212 through a gas flow path 211. The gas flow path 211 may pass inside the substrate support section 11. The heat transfer gas supply section 212 may be provided outside the chamber 10. As shown in Figure 4, the first upper surface 200 has a circular shape with the center of the ceramic member 1111a as its center. The gas outlet section 210 is located at the center of the first upper surface 200. Note that there may be one or more gas outlet sections 210. The heat transfer gas may contain helium gas.

[0042] In one embodiment, a plurality of protrusions 220 are arranged on the first upper surface 200. As shown in Figure 3, the protrusions 220 project 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 Figure 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 with respect to the center of the first upper surface 200.

[0043] In one embodiment, as shown in Figures 3 and 4, the seal band 201 is an annular protrusion that projects upward from the first upper surface 200. The seal band 201 is arranged in an annular shape with the center of the ceramic member 1111a as its center.

[0044] As shown in Figure 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 an annular horizontal surface. The second upper surface 252 connects the upper end of the inner circumferential wall 250 and the upper end of 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-angle 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 radial width (X direction shown in Figures 4 and 5) D1 of the second upper surface 252 (length from the inner end to the outer end of the seal band 201) may be 0.3 mm or more and 4 mm or less. The height H1 of the seal band 201 may be 5 μm or more and 50 μm or less.

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

[0047] As shown in Figure 3, the electrostatic chuck electrode 1111b includes a first electrostatic electrode 300 positioned below the first upper surface 200 inside the ceramic member 1111a, and a second electrostatic electrode 301 positioned 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 horizontally disposed. 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 having thicknesses 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 surfaces, and the inner surface 322 and the outer surface 323 are vertical surfaces. The second electrode lower surface 321 may be disposed at the same height as the first electrode lower surface 311 of the first electrostatic electrode 300. The second electrode upper surface 320 is disposed at a position higher than the first electrode upper surface 310 of the first electrostatic electrode 300.

[0052] A first vertical distance a1 between the second upper surface 252 and the second electrostatic electrode 301 (second electrode upper surface 320) is smaller (a1 < a2) than a second vertical distance a2 between a first horizontal plane P1 including the first electrostatic electrode 300 (first electrode upper surface 310) and the second upper surface 252. 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 the third vertical distance a3 between the second horizontal plane P2 containing the first upper surface 200 and the second upper surface 252 (a1 > a3). That is, the second electrostatic electrode 301 is located 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] 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 (a4≧a5). That is, the second electrostatic electrode 301 is sufficiently far 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 more. The 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 more.

[0056] As shown in Figure 3, the first electrostatic electrode 300 and the second electrostatic electrode 301 are electrically connected to a single DC power supply 351 via a switch 350. By applying a DC voltage to the first electrostatic electrode 300 and the second electrostatic electrode 301 from the DC power supply 351, an electrostatic attraction (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 this electrostatic attraction and is held by adsorption on the upper surface of the ceramic member 1111a.

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

[0058] First, the substrate W is brought into the chamber 10, and as shown in Figure 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 electrodes 1111b (first electrostatic electrode 300 and second electrostatic electrode 301) by the DC power supply 351, generating an electrostatic attraction between the ceramic member 1111a and the substrate W, and the substrate W is 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 control module, and the substrate W of the electrostatic chuck 1111 is temperature-controlled to a given temperature. The heat from the substrate W is transferred from the sealing band 201 to the heat transfer medium via the ceramic member 1111a and the base 1110.

[0060] Heat transfer gas is supplied from the heat transfer gas supply unit 212 to the gas outlet unit 210, and from the gas outlet unit 210, the heat transfer gas is supplied 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 to prevent the heat transfer gas filling the space E1 from leaking into the plasma processing space 10s. The heat transfer gas regulates the temperature of the substrate W from its back side.

[0061] The processing gas is supplied to the showerhead 13 by the gas supply unit 20 shown in Figure 2, and then supplied from the showerhead 13 to the plasma processing space 10s. The processing gas supplied at this time includes a gas that generates the active species necessary for etching the substrate W.

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

[0063] According to this exemplary embodiment, the electrostatic chuck 1111 comprises a ceramic member 1111a including a first upper surface 200 and an annular seal band 201; a first electrostatic electrode 300 disposed below the first upper surface 200 within the ceramic member 1111a; and a second electrostatic electrode 301 disposed below the second upper surface 252 of the seal band 201 within the ceramic member 1111a and electrically connected to the first electrostatic electrode 300. The second electrostatic electrode 301 is configured such that a first vertical distance a1 between the second upper surface 252 and the second electrostatic electrode 301 is smaller than a second vertical distance a2 between a first horizontal plane P1 including the first electrostatic electrode 300 and the second upper surface 252, and is larger than a third vertical distance a3 between a second horizontal plane P2 including the first upper surface 200 and the second upper surface 252, and the inner end of the second electrostatic electrode 301 is located outside the inner end of the seal band 201. Since the first distance a1 is smaller than the second distance a2, the distance between the second electrostatic electrode 301 and the substrate becomes closer than the distance between the first electrostatic electrode 300 and the substrate, thereby improving the electrostatic attraction force of the seal band 201 of the electrostatic chuck 1111 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, since the first distance a1 is larger than the third distance a3, and the inner end of the second electrostatic electrode 301 is located outside the inner end of the seal band 201, insulation between the second electrostatic electrode 301 and the periphery of the seal band 201 can be ensured. In addition, since the first electrostatic electrode 300 and the second electrostatic electrode 301 are electrically connected, power can be supplied to both 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. This ensures 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 greater vertical thickness than the first electrostatic electrode 300. This makes it easier to form the second electrostatic electrode 301. In addition, the thermal conductivity of the second electrostatic electrode 301 is increased, making it easier to transfer heat from the outer periphery of the substrate to the ceramic member 1111a through the sealing band 201.

[0067] The second electrostatic electrode 301 may have other configurations. As shown in Figure 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 about 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 lower electrode surface 321 of the second electrostatic electrode 301 is positioned higher than the lower electrode surface 311 and the upper electrode surface 310 of the first electrostatic electrode 300. The first electrostatic electrode 300 and the second electrostatic electrode 301 are connected by a connecting electrode 400. The connecting electrode 400 may be annular. The connecting 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 formed integrally.

[0068] As shown in Figure 7, the first electrostatic electrode 300 and the second electrostatic electrode 301 may be connected by a connecting wire 450. The connecting wire 450 has a first connecting end 460 connected to the lower surface 311 of the first electrode of the first electrostatic electrode 300, and a second connecting end 461 connected to the lower surface 321 of the second electrode of the second electrostatic electrode 301. Multiple connecting wires 450 may be provided. The first electrostatic electrode 300, the second electrostatic electrode 301, and the connecting wire 450 may be formed separately. The connecting wire 450 can be routed to pass inside the ceramic member 1111a or on the lower outside of the ceramic member 1111a.

[0069] As shown in Figure 8, the upper surface 320 of the second electrostatic electrode 301 may be inclined to become higher as it approaches the outer end from the inner end. The second upper surface 252 of the seal band 201 may be inclined to become higher as it approaches the outer end from the inner end, similar to the upper surface 320 of the second electrode. The upper surfaces 320 and 252 of the second electrode 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 connecting wiring 450. The first distance a1 is the shortest vertical distance between the second upper surface 252 and the upper surface 320 of the second electrode. The second distance a2 is the shortest vertical distance between the first horizontal plane P1 of the first electrostatic electrode 300 and the second upper surface 252 of the second electrode. The third distance a3 is the shortest vertical distance between the second upper surface 252 and the second horizontal plane P2 of the first upper surface 200.

[0070] In the embodiments described above, an example of the electrostatic chuck 1111 being used in a capacitively coupled plasma apparatus was explained, but it 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 this disclosure further include the following embodiments:

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

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

[0074] (Note 3) The fourth distance is 100 μm or more. The electrostatic chuck described in Appendix 2.

[0075] (Note 4) The 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. The electrostatic chuck described in Appendix 2.

[0076] (Note 5) The sixth distance is 100 μm or more. The electrostatic chuck described in Appendix 4.

[0077] (Note 6) The vertical thickness of the second electrostatic electrode is greater than the vertical thickness of the first electrostatic electrode. An electrostatic chuck as described in any one of the items 1 to 5 of the appendix.

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

[0079] (Note 8) The second electrostatic electrode is positioned higher than the first electrostatic electrode. An electrostatic chuck as described in any one of the items 1 to 5 of the appendix.

[0080] (Note 9) The upper surface of the second electrostatic electrode is sloped so that it gradually becomes higher from the inner end to the outer end. An electrostatic chuck as described in any one of the items 1 to 8 of the appendix.

[0081] (Note 10) The second upper surface is sloped so that it gradually becomes higher from the inner end to the outer end. An electrostatic chuck as described in any one of the items 1 to 9 of the appendix.

[0082] (Note 11) The invention further comprises a connecting electrode that electrically connects the first electrostatic electrode and the second electrostatic electrode. An electrostatic chuck as described in any one of the appendices 1 to 10.

[0083] (Note 12) The invention further comprises connecting wiring that electrically connects the first electrostatic electrode and the second electrostatic electrode. An electrostatic chuck as described in any one of the appendices 1 to 10.

[0084] The embodiments described above are for illustrative purposes only and are not intended to limit the scope of this disclosure. The embodiments described above can be modified in various ways without departing from the scope and spirit of this disclosure. For example, some components of one embodiment can be added to other embodiments, or some components of one embodiment can be replaced with corresponding components of other embodiments. [Explanation of Symbols]

[0085] 1...Plasma processing apparatus, 10...Chamber, 11...Substrate support part, 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 plane, P2...Second horizontal plane, W...Substrate

Claims

1. A dielectric member configured to support a substrate, wherein the dielectric member includes a first upper surface and an annular sealing band disposed outside the first upper surface, and the sealing band has a second upper surface that is higher than the first upper surface, A first electrostatic electrode is disposed below the first upper surface within the dielectric member, A second electrostatic electrode is positioned below the second upper surface within the dielectric member and electrically connected to the first electrostatic electrode, wherein the second electrostatic electrode is 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 the first horizontal plane including the first electrostatic electrode and the second upper surface, and larger than a third vertical distance between the second horizontal plane including the first upper surface and the second upper surface, and the inner end of the second electrostatic electrode is located outside the inner end of the seal band. Electrostatic chuck.

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

3. The fourth distance is 100 μm or more. The electrostatic chuck according to claim 2.

4. The 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. The electrostatic chuck according to claim 2.

5. The sixth distance is 100 μm or more. The electrostatic chuck according to claim 4.

6. The vertical thickness of the second electrostatic electrode is greater than the vertical thickness of the first electrostatic electrode. The electrostatic chuck according to claim 1.

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

8. The second electrostatic electrode is positioned higher than the first electrostatic electrode. The electrostatic chuck according to claim 1.

9. The upper surface of the second electrostatic electrode is inclined so that it gradually becomes higher from the inner end to the outer end. The electrostatic chuck according to claim 1.

10. The second upper surface is sloped so that it gradually becomes higher from the inner end to the outer end. The electrostatic chuck according to claim 9.

11. The device further comprises a connecting electrode that electrically connects the first electrostatic electrode and the second electrostatic electrode. The electrostatic chuck according to claim 1.

12. The device further comprises connecting wiring that electrically connects the first electrostatic electrode and the second electrostatic electrode. The electrostatic chuck according to claim 1.

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