Electrostatic chuck

Abstract

This electrostatic chuck includes a dielectric member having a substrate support surface, and an electrostatic electrode disposed below the substrate support surface in the dielectric member. The dielectric member includes a first upper region disposed between the substrate support surface and the electrostatic electrode, and a second region disposed between the substrate support surface and the electrostatic electrode and disposed outside the first upper region. The first upper region has a first dielectric constant, and the second upper region has a second dielectric constant larger than the first dielectric constant.

Description

Electrostatic chuck

[0001] An exemplary embodiment of the present disclosure relates to an electrostatic chuck.

[0002] As a technique for providing an electrostatic chuck that electrostatically adsorbs a substrate, there is a technique described in Patent Document 1.

[0003] Japanese Unexamined Patent Application Publication No. 2016-207806

[0004] The present disclosure provides a technique capable of improving the electrostatic adsorption force on the outer peripheral portion of the substrate in the electrostatic chuck.

[0005] The electrostatic chuck in one exemplary embodiment of the present disclosure includes a dielectric member having a substrate support surface, and an electrostatic electrode disposed below the substrate support surface in the dielectric member. The dielectric member includes a first upper region disposed between the substrate support surface and the electrostatic electrode, and a second region disposed between the substrate support surface and the electrostatic electrode and outside the first upper region. The first upper region has a first dielectric constant, and the second upper region has a second dielectric constant greater than the first dielectric constant.

[0006] According to one exemplary embodiment of the present disclosure, a technique capable of improving the electrostatic adsorption force on the outer peripheral portion of the substrate in the electrostatic chuck is provided.

[0007] It is a diagram for explaining a configuration example of a plasma processing system. It is a diagram for explaining a configuration example of a capacitively coupled plasma processing apparatus. It is a diagram for explaining a configuration example of a substrate support portion. It is a top view of an electrostatic chuck for explaining a configuration example of the electrostatic chuck. It is a diagram for explaining a configuration example of the electrostatic chuck. It is a diagram for explaining another configuration example of the electrostatic chuck. It is a diagram for explaining another configuration example of the electrostatic chuck. It is a diagram for explaining another configuration example of the electrostatic chuck. It is a diagram for explaining another configuration example of the electrostatic chuck. It is a diagram for explaining another configuration example of the electrostatic chuck.

[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 having a substrate support surface and an electrostatic electrode disposed below the substrate support surface within the dielectric member, wherein the dielectric member includes a first upper region disposed between the substrate support surface and the electrostatic electrode, and a second region disposed between the substrate support surface and the electrostatic electrode and located outside the first upper region, the first upper region having a first dielectric constant, and the second upper region having a second dielectric constant greater than the first dielectric constant.

[0010] In one exemplary embodiment, the second dielectric constant is constant within the second upper region.

[0011] In one exemplary embodiment, the second dielectric constant varies within the second upper region.

[0012] In one exemplary embodiment, the second dielectric constant gradually increases from the inside to the outside within the second upper region.

[0013] In one exemplary embodiment, the dielectric member is positioned outside a first upper region between the substrate support surface and the electrostatic chuck electrode and includes a third upper region positioned above or below at least one of the second upper region, wherein the third upper region has a third dielectric constant.

[0014] In one exemplary embodiment, the third dielectric constant is equal to the first dielectric constant.

[0015] In one exemplary embodiment, the third dielectric constant is equal to the second dielectric constant.

[0016] In one exemplary embodiment, the dielectric member has an annular sealing band located on the outer upper part of the dielectric member, the sealing band being included in a second upper region.

[0017] In one exemplary embodiment, the dielectric member has a plurality of projections located on the inner upper part of the dielectric member, the plurality of projections being included in a first upper region.

[0018] In one exemplary embodiment, the dielectric member further includes a lower region located beneath the electrostatic chuck electrode, the lower region having a first dielectric constant.

[0019] In one exemplary embodiment, the dielectric member further includes a first lower region located below the electrostatic chuck electrode and a second lower region located outside the first lower region below the electrostatic chuck electrode, wherein the first lower region has a first dielectric constant and the second lower region has a second dielectric constant.

[0020] In one exemplary embodiment, the first lower region is located below the first upper region, and the second lower region is located below the second upper region.

[0021] Hereinafter, each embodiment of this disclosure will be described in detail with reference to the drawings. In each drawing, the same or similar elements are denoted by the same reference numeral, and redundant explanations are omitted. Unless otherwise specified, positional relationships such as top, bottom, 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 actual ratios are not limited to those shown.

[0022] <An example of a plasma treatment system>

[0023] 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.

[0024] 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 capacitively coupled plasma (CCP), inductively coupled plasma (ICP), ECR (Electron Cyclotron Resonance) plasma, helicon wave excited plasma (HWP), or surface wave plasma (SWP), etc. Various types of plasma generation units, including AC (Alternating Current) plasma generation units and DC (Direct Current) plasma generation units, 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.

[0025] 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 the elements of the plasma processing apparatus 1 to perform the various processes described herein. In one embodiment, part or all of the control unit 2 may be included in the plasma processing apparatus 1. The control unit 2 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 realized by the processing unit 2a1 described herein may be implemented in a circuit or processing circuit, including a general-purpose processor, an application-specific processor, integrated circuits, ASICs (Application Specific Integrated Circuits), a CPU (Central Processing Unit), a conventional circuit, and / or a combination thereof, programmed to realize the described functions. The processor is considered to be a circuit or processing circuit, including transistors and other circuits. The processor may be a programmed processor that executes a program stored in the storage unit 2a2. This program may be pre-stored in the storage unit 2a2 or retrieved via a medium when needed. The acquired program is stored in the storage unit 2a2 and read from the storage 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 storage unit 2a2 may include RAM (Random Access Memory), ROM (Read Only Memory), HDD (Hard Disk Drive), SSD (Solid State Drive), or a combination thereof. The communication interface 2a3 may communicate with the plasma processing 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.

[0026] The following describes an example configuration of a capacitively coupled plasma processing apparatus as an example of a plasma processing apparatus 1. Figure 2 is a diagram illustrating an example configuration of a capacitively coupled plasma processing apparatus.

[0027] 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.

[0028] 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 a 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.

[0029] 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 it may be placed on both the electrostatic chuck 1111 and the annular insulating member. In addition, at least one bias electrode, which is electrically connected or coupled to the power supply 31 and / or power supply 32 described later, may be placed inside 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 inside 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 inside 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.

[0030] 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.

[0031] 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.

[0032] 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.

[0033] 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.

[0034] 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. Therefore, 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.

[0035] 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. One or more generated source RF signals are supplied to at least one lower electrode and / or at least one upper electrode.

[0036] 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. When 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 frequency lower 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.

[0037] 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 is 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 is configured to generate a second voltage signal. The generated second voltage signal is applied to at least one upper electrode.

[0038] 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 a plurality of 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, the burst of voltage pulses is 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 rectangle, trapezoid, triangle, 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.

[0039] 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.

[0040] <Example of Electrostatic Chuck Configuration> Figure 3 is a diagram illustrating an example of the configuration of the electrostatic chuck 1111 in this exemplary embodiment. In one embodiment, the electrostatic chuck 1111 has a dielectric member 1111a and an electrostatic chuck electrode 1111b. An example of the dielectric member 1111a is a ceramic member. The electrostatic chuck 1111 may electrostatically attract a substrate with a diameter of 300 mm.

[0041] In one embodiment, the dielectric member 1111a has a disc shape. The dielectric member 1111a has a substrate support surface 1111c for supporting a substrate on its upper surface. In one embodiment, the dielectric member 1111a has a first upper surface 200, an annular seal band 201 disposed outside the first upper surface 200, and a plurality of protrusions 202 disposed on the first upper surface 200.

[0042] In one embodiment, the first upper surface 200 has a gas outflow portion 210 through which the heat transfer gas flows out. In one embodiment, the gas outflow portion 210 is connected to a heat transfer gas supply portion 212 through a gas flow path 211. The gas flow path 211 may pass through the inside of the substrate support portion 11. The heat transfer gas supply portion 212 may be provided outside the chamber 10. As shown in FIG. 4, the first upper surface 200 has a circular shape centered on the center of the dielectric member 1111a. The gas outflow portion 210 is disposed at the center of the first upper surface 200. Note that one or more gas outflow portions 210 may be provided. The heat transfer gas may contain helium gas.

[0043] As shown in FIG. 3, the plurality of protrusions (substrate support portions) 202 are disposed on the first upper surface 200. The protrusions 202 protrude upward with respect to the first upper surface 200. The protrusions 202 may have a cylindrical shape. The protrusions 202 have a flat protrusion upper surface 220. The height of the protrusions 202 with respect 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 202 may be arranged at equal intervals along the circumferential direction around the center of the first upper surface 200. The plurality of protrusions 202 may be arranged concentrically or radially with respect to the center of the first upper surface 200. The plurality of protrusions 202 may be integrally formed with other portions including the first upper surface 200 in the dielectric member 1111a, or may be formed separately.

[0044] In one embodiment, as shown in FIGS. 3 and 4, the seal band 201 is an annular convex portion that protrudes above the first upper surface 200. The seal band 201 is arranged in an annular shape centered on the center of the dielectric member 1111a.

[0045] As shown in FIG. 5, the seal band 201 has an inner peripheral wall 250, an outer peripheral wall 251, and a second upper surface 252. In one embodiment, the inner peripheral wall 250 and the outer peripheral wall 251 are annular vertical surfaces. The second upper surface 252 is an annular horizontal surface. The second upper surface 252 connects the upper ends of the inner peripheral wall 250 and the outer peripheral wall 251. The second upper surface 252 may be disposed at the same or a higher position than the protruding upper surface 220 of the protrusion 202. The height of the seal band 201 with respect to the first upper surface 200 may be 5 μm or more and 50 μm or less.

[0046] In one embodiment, the substrate support surface 1111c may be constituted by the first upper surface 200, the protruding upper surface 220 of the protrusion 202, and the second upper surface 252 of the seal band 201. The outer diameter of the seal band 201 may be smaller than the diameter of the substrate W. That is, the substrate support surface 1111c may be smaller than the substrate W, and when the substrate W is supported on the substrate support surface 1111c, the outer peripheral end of the substrate W may protrude outside the seal band 201. The seal band 201 may be integrally formed with other portions including the first upper surface 200 in the dielectric member 1111a, or may be formed separately.

[0047] As shown in FIG. 3, the electrostatic chuck electrode 1111b is disposed below the substrate support surface 1111c inside the dielectric member 1111a. The electrostatic chuck electrode 1111b has a thin plate shape and is disposed horizontally. In one embodiment, as shown in FIG. 4, the electrostatic chuck electrode 1111b has a circular shape having the same center as the first upper surface 200. As shown in FIG. 5, the outer end of the electrostatic chuck electrode 1111b extends below the seal band 201. The electrostatic chuck electrode 1111b may be a single body or may be divided into a plurality of parts. The material of the electrostatic chuck electrode 1111b is a conductive member.

[0048] As shown in Figure 3, the electrostatic chuck electrode 1111b is electrically connected to a DC power supply 351 via a switch 350. By applying a DC voltage to the electrostatic chuck electrode 1111b using the DC power supply 351, an electrostatic attractive force (Coulomb force) can be generated between the dielectric member 1111a and the substrate W. The substrate W is attracted to the dielectric member 1111a by this electrostatic attractive force and is held by adsorption on the upper surface of the dielectric member 1111a.

[0049] In one embodiment, as shown in Figure 5, the dielectric member 1111a includes a first upper region 500 positioned between the substrate support surface 1111c and the height position of the electrostatic chuck electrode 1111b (above the electrostatic chuck electrode 1111b), a second upper region 501 positioned between the substrate support surface 1111c and the height position of the electrostatic chuck electrode 1111b and positioned outside the first upper region, a third upper region 502 positioned between the substrate support surface 1111c and the height position of the electrostatic chuck electrode 1111b and positioned outside the first upper region 500, and a lower region 503 positioned below the electrostatic chuck electrode 1111b.

[0050] In one embodiment, the second upper region 501 is a seal band 201. In one embodiment, the third upper region 502 is located below the second upper region 501. The third upper region 502 may be an annular region located below the second upper region 501. The first upper region 500 may be a disc-shaped region located inside the second upper region 501 and the third upper region 502. In one embodiment, the lower region 503 is located below the first upper region 500 and the third upper region 502. The lower region 503 may be a disc-shaped region.

[0051] In one embodiment, the first upper region 500 is configured to have a first dielectric constant R1. The second upper region 501 is configured to have a second dielectric constant R2 which is greater than the first dielectric constant R1. The third upper region 502 is configured to have a third dielectric constant R3. In one embodiment, the third dielectric constant R3 is equal to the first dielectric constant R1. The lower region 503 is configured to have a first dielectric constant R1. That is, in one embodiment, the first upper region 500, the third upper region 502, and the lower region 503 all have the same first dielectric constant R1. Note that in Figures 5 to 10, regions having the same dielectric constant are shown with the same pattern. The first upper region 500, the third upper region 502, and the lower region 503 are made of a dielectric material having a first dielectric constant R1. The dielectric material of the first upper region 500, the third upper region 502, and the lower region 503 may be at least one selected from the group consisting of alumina, aluminum nitride, and yttria (yttrium oxide). The first dielectric constant R1 is 35 × 10⁻⁶. －１２ F / m ~ 300 x 10 －１２ It may be within the range of F / m.

[0052] In one embodiment, the second upper region 501 is a dielectric base material to which a high dielectric material has been added. The base material of the second upper region 501 may be at least one selected from the group consisting of alumina, aluminum nitride, yttria (yttrium oxide), zirconia, and barium titanate. The base material of the second upper region 501 may be the same material as that of the first upper region 500. The second dielectric constant R2 is 70 × 10⁻⁶. －１２ F / m~44270×10 －１２ The ratio may be within the range of F / m. The first upper region 500, the second upper region 501, the third upper region 502, and the lower region 503 may be integrally molded by firing. In this case, a high dielectric material may be added to the second upper region 501 during firing. Alternatively, the second upper region 501 may be molded separately and then bonded to the other first upper region 500 and the third upper region 502 afterward.

[0053] <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.

[0054] First, the substrate W is brought into the chamber 10, and as shown in Figure 3, the substrate W is placed on the dielectric member 1111a of the electrostatic chuck 1111. The substrate W is supported by the seal band 201 and the projection 202. Then, a DC voltage is applied to the electrostatic chuck electrode 1111b by the DC power supply 351, generating an electrostatic attraction between the dielectric member 1111a and the substrate W, and the substrate W is electrostatically attracted to the seal band 201 of the electrostatic chuck 1111.

[0055] 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 seal band 201 to the heat transfer medium via the dielectric member 1111a and the base 1110.

[0056] 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 formed between the substrate W and the first upper surface 200. The seal band 201 seals the space between the first upper surface 200 and the substrate W to prevent the heat transfer gas filling the space from leaking into the plasma processing space 10s. The heat transfer gas regulates the temperature of the substrate W from its back side.

[0057] 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.

[0058] 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.

[0059] According to this exemplary embodiment, the electrostatic chuck 1111 comprises a dielectric member 1111a having a substrate support surface 1111c, and an electrostatic chuck electrode 1111b disposed below the substrate support surface 1111c within the dielectric member 1111a. The dielectric member 1111a includes a first upper region 500 disposed between the substrate support surface 1111c and the electrostatic chuck electrode 1111b, and a second upper region 501 disposed between the substrate support surface 1111c and the electrostatic chuck electrode 1111b and located outside the first upper region 500, wherein the first upper region 500 has a first dielectric constant R1, and the second upper region 501 has a second dielectric constant R2 which is greater than the first dielectric constant R1. Because the dielectric constant of the second upper region 501 is greater than that of the first upper region 500, when a voltage is applied to the electrostatic chuck electrode 1111b, the electrostatic attraction force of the outer second upper region 501 becomes greater than the electrostatic attraction force of the inner first upper region 500. As a result, the electrostatic attraction force of the electrostatic chuck 1111 to the outer periphery of the substrate can be improved. This makes it easier to transfer heat from the outer periphery of the substrate to the dielectric member 1111a through the seal band 201, thus making it easier to regulate the temperature of the outer periphery of the substrate. In addition, when the substrate W extends beyond the seal band 201, the heat from the protruding portion of the substrate W can be transferred to the dielectric member 1111a, thereby regulating the temperature of the protruding portion of the substrate W.

[0060] In the above embodiment, as shown in Figure 6, the second upper region 501 may include the lower region of the seal band 201. The second upper region 501 may include the region lower than the first upper surface 200. The second upper region 501 may include the inner region of the seal band 201. The second upper region 501 may include the region including the first upper surface 200.

[0061] In the above embodiment, as shown in Figure 7, the third upper region 502 may be positioned above the second upper region 501. In this case, the third upper region 502 may have a third dielectric constant R3 equal to the first dielectric constant R1. In this case, the third upper region 502 may include a seal band 201.

[0062] Furthermore, as shown in Figure 8, the third dielectric constant R3 of the third upper region 502 may be equal to the second dielectric constant R2. In this case, the second upper region 501 and the third upper region 502 of the outer periphery of the dielectric member 1111a have a high second dielectric constant R2. The entire region above the electrostatic chuck electrode 1111b on the outer periphery of the dielectric member 1111a may have a second dielectric constant R2.

[0063] As shown in Figure 9, the dielectric member 1111a may include a first lower region 600 located below the electrostatic chuck electrode 1111b and a second lower region 601 located outside the first lower region 600 below the electrostatic chuck electrode 1111b. In one embodiment, the first lower region 600 is located below the first upper region 500, and the second lower region 601 is located below the second upper region 501. The first lower region 600 may have a first dielectric constant R1, and the second lower region 601 may have a second dielectric constant R2. In this case, the entire outer region of the dielectric member 1111a may have the second dielectric constant R2.

[0064] In the embodiments described above, the second dielectric constant R2 was constant within the second upper region 501, but as shown in Figure 10, the second dielectric constant R2 may vary within the second upper region 501. In one embodiment, the second dielectric constant R2 gradually increases from the inside to the outside within the second upper region 501. In this case, during firing, the amount of high dielectric constant material added to the second upper region 501 may be gradually increased from the inside to the outside. Furthermore, in the third upper region 502 and the second lower region 601, the second dielectric constant R2 may be gradually increased from the inside to the outside.

[0065] In the above embodiment, the third upper region 502 may have a third dielectric constant R3 that is different from the first dielectric constant R1 and the second dielectric constant R2.

[0066] In the embodiments described above, the first dielectric constant R1 is constant in the first upper region 500 and the first lower region 600, but it may vary.

[0067] In the embodiments described above, an example in which the electrostatic chuck 1111 is used in a capacitively coupled plasma apparatus has been 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.

[0068] Embodiments of this disclosure further include the following embodiments:

[0069] (Note 1) An electrostatic chuck comprising: a dielectric member having a substrate support surface; and an electrostatic chuck electrode disposed below the substrate support surface within the dielectric member, wherein the dielectric member includes: a first upper region disposed between the substrate support surface and the electrostatic chuck electrode; and a second upper region disposed between the substrate support surface and the electrostatic chuck electrode and located outside the first upper region, wherein the first upper region has a first dielectric constant, and the second upper region has a second dielectric constant greater than the first dielectric constant.

[0070] (Note 2) The electrostatic chuck according to Note 1, wherein the second dielectric constant is constant within the second upper region.

[0071] (Note 3) The electrostatic chuck according to Note 1, wherein the second dielectric constant varies within the second upper region.

[0072] (Note 4) The electrostatic chuck according to Note 3, wherein the second dielectric constant gradually increases from the inside to the outside within the second upper region.

[0073] (Note 5) The electrostatic chuck according to any one of Notes 1 to 4, wherein the dielectric member is located outside the first upper region between the substrate support surface and the electrostatic chuck electrode, and includes a third upper region located above or below the second upper region, the third upper region having a third dielectric constant.

[0074] (Note 6) The electrostatic chuck described in Note 5, wherein the third dielectric constant is equal to the first dielectric constant.

[0075] (Note 7) The electrostatic chuck described in Note 5, wherein the third dielectric constant is equal to the second dielectric constant.

[0076] (Note 8) The electrostatic chuck according to any one of Notes 1 to 7, wherein the dielectric member has an annular sealing band disposed on the outer upper part of the dielectric member, and the sealing band is included in the second upper region.

[0077] (Note 9) The electrostatic chuck according to any one of Notes 1 to 8, wherein the dielectric member has a plurality of protrusions arranged on the inner upper part of the dielectric member, and the plurality of protrusions are included in the first upper region.

[0078] (Note 10) The electrostatic chuck according to any one of Notes 1 to 9, wherein the dielectric member further includes a lower region located below the electrostatic chuck electrode, and the lower region has the first dielectric constant.

[0079] (Note 11) The electrostatic chuck according to any one of Notes 1 to 9, wherein the dielectric member further includes a first lower region disposed below the electrostatic chuck electrode and a second lower region disposed outside the first lower region below the electrostatic chuck electrode, the first lower region having the first dielectric constant and the second lower region having the second dielectric constant.

[0080] (Note 12) The electrostatic chuck according to Note 11, wherein the first lower region is located below the first upper region, and the second lower region is located below the second upper region.

[0081] 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.

[0082] 1...Plasma processing apparatus, 10...Chamber, 11...Substrate support part, 1111...Electrostatic chuck, 1111a...Dielectric member, 1111b...Electrostatic chuck electrode, 1111c...Substrate support surface, 200...First upper surface, 201...Seal band, 202...Protrusion, 500...First upper region, 501...Second upper region, 502...Third upper region, 503...Lower region, R1...First dielectric constant, R2...Second dielectric constant, W...Substrate

Claims

1. An electrostatic chuck comprising: a dielectric member having a substrate support surface; and an electrostatic chuck electrode disposed below the substrate support surface within the dielectric member, wherein the dielectric member includes: a first upper region disposed between the substrate support surface and the electrostatic chuck electrode; and a second upper region disposed between the substrate support surface and the electrostatic chuck electrode and located outside the first upper region, wherein the first upper region has a first dielectric constant, and the second upper region has a second dielectric constant greater than the first dielectric constant.

2. The electrostatic chuck according to claim 1, wherein the second dielectric constant is constant within the second upper region.

3. The electrostatic chuck according to claim 1, wherein the second dielectric constant varies within the second upper region.

4. The electrostatic chuck according to claim 3, wherein the second dielectric constant gradually increases from the inside to the outside within the second upper region.

5. The electrostatic chuck according to claim 1, wherein the dielectric member is positioned outside the first upper region between the substrate support surface and the electrostatic chuck electrode, and includes a third upper region positioned above or below the second upper region, the third upper region having a third dielectric constant.

6. The electrostatic chuck according to claim 5, wherein the third dielectric constant is equal to the first dielectric constant.

7. The electrostatic chuck according to claim 5, wherein the third dielectric constant is equal to the second dielectric constant.

8. The electrostatic chuck according to claim 1, wherein the dielectric member has an annular sealing band disposed on the outer upper part of the dielectric member, and the sealing band is included in the second upper region.

9. The electrostatic chuck according to claim 8, wherein the dielectric member has a plurality of protrusions arranged on the inner upper part of the dielectric member, and the plurality of protrusions are included in the first upper region.

10. The electrostatic chuck according to claim 1, wherein the dielectric member further includes a lower region disposed below the electrostatic chuck electrode, and the lower region has the first dielectric constant.

11. The electrostatic chuck according to claim 1, wherein the dielectric member further includes a first lower region disposed below the electrostatic chuck electrode and a second lower region disposed below the electrostatic chuck electrode and outside the first lower region, the first lower region having a first dielectric constant and the second lower region having a second dielectric constant.

12. The electrostatic chuck according to claim 11, wherein the first lower region is located below the first upper region, and the second lower region is located below the second upper region.

Images