Substrate processing device and electrostatic chuck

Abstract

This electrostatic chuck comprises a chuck main body part having an upper surface, at least one first gas supply path, and at least one second gas supply path. The upper surface has a plurality of bumps, a first annular groove, a second annular groove that surrounds the first annular groove, and an annular protrusion that is disposed between the first annular groove and the second annular groove, protrudes from the upper surface, and is lower than the bumps. The first annular groove communicates with the at least one first gas supply path through at least one first gas supply hole, and the second annular groove communicates with the at least one second gas supply path through at least one second gas supply hole.

Description

Substrate processing apparatus and electrostatic chuck

[0001] The present disclosure relates to a substrate processing apparatus and an electrostatic chuck.

[0002] The '611 patent discloses an electrostatic chuck that includes a plurality of sealing bands located on the chuck surface that contact the substrate to form a seal between adjacent cooling zones.

[0003] Patent Document 2 discloses that an outer ring is provided around the outermost periphery of the substrate holding surface of an electrostatic chuck, and the outer ring comes into contact with the substrate when the substrate is placed on the substrate holding surface.

[0004] JP 2020-512692 A JP 2006-257495 A

[0005] The technology according to the present disclosure appropriately controls the temperature of the substrate and improves the uniformity of the plasma processing within the substrate surface.

[0006] A substrate processing apparatus according to one aspect of the present disclosure includes a substrate processing chamber, a substrate support disposed within the substrate processing chamber and having at least one first gas supply line and at least one second gas supply line, a base, and an electrostatic chuck disposed on the base and having an upper surface, the upper surface being formed with a plurality of protrusions, a first annular groove, a second annular groove surrounding the first annular groove, and an annular convex portion disposed between the first annular groove and the second annular groove, protruding from the upper surface and lower than the protrusions, and the first annular groove has at least one first gas supply hole. the electrostatic chuck, the electrostatic chuck having a first annular groove communicating with the at least one first gas supply line through a first annular groove and the second annular groove communicating with the at least one second gas supply line through at least one second gas supply hole; at least one first control valve configured to control a flow rate or a pressure of the gas supplied through the at least one first gas supply line; and at least one second control valve configured to control a flow rate or a pressure of the gas supplied through the at least one second gas supply line.

[0007] According to the present disclosure, it is possible to appropriately control the temperature of the substrate and improve the uniformity of the plasma processing within the surface of the substrate.

[0008] 1 is an explanatory diagram schematically showing the configuration of a plasma processing system; FIG. 2 is a longitudinal sectional view showing the outline of the configuration of a plasma processing apparatus; FIG. 3 is a plan view showing the outline of the configuration of an electrostatic chuck according to a first embodiment; FIG. 4 is a longitudinal sectional view showing the outline of the configuration of an electrostatic chuck according to the first embodiment; FIG. 5 is a sectional perspective view showing the outline of the configuration of an electrostatic chuck according to the first embodiment, and an explanatory diagram showing pressure distribution in a heat transfer space; FIG. 6 is a plan view showing the outline of a partial configuration of an electrostatic chuck according to the first embodiment; FIG. 7 is a plan view showing the outline of a partial configuration of an electrostatic chuck according to the first embodiment; FIG. 8 is a graph showing the results of a simulation in the first embodiment; FIG. 9 is a graph showing the results of a simulation in the first embodiment; FIG. 10 is a sectional perspective view showing the outline of the configuration of an electrostatic chuck according to a modified example of the first embodiment; FIG. 11 is a plan view showing the outline of a partial configuration of an electrostatic chuck according to a modified example of the first embodiment; FIG. 12 is a plan view showing the outline of a partial configuration of an electrostatic chuck according to a second embodiment; FIG. 13 is a graph showing the results of a simulation in the second embodiment; FIG. 14 is a plan view showing the outline of a partial configuration of an electrostatic chuck according to a third embodiment; FIG. 15 is a sectional perspective view showing the outline of the configuration of an electrostatic chuck according to a third embodiment, and an explanatory diagram showing pressure distribution in a heat transfer space. Fig. 10 is a plan view showing an outline of a partial configuration of an electrostatic chuck according to a fourth embodiment; Fig. 11 is a longitudinal sectional view showing an outline of a configuration of an annular convex portion according to a sixth embodiment; Fig. 12 is a longitudinal sectional view showing an outline of a configuration of an annular convex portion according to a sixth embodiment; Fig. 13 is a plan view showing an outline of a configuration of an annular convex portion according to a sixth embodiment; Fig. 14 is a plan view showing an outline of a configuration of an annular convex portion according to a sixth embodiment;

[0009] In the manufacturing process of semiconductor devices, for example, a plasma processing is performed on a semiconductor substrate (hereinafter referred to as "substrate") in a plasma processing apparatus. In the plasma processing apparatus, a processing gas is excited inside a chamber to generate plasma, and the substrate supported by an electrostatic chuck is processed by the plasma.

[0010] In plasma processing, in order to improve the in-plane uniformity of the plasma processing on the substrate, it is necessary to appropriately control the temperature of the substrate to be processed. Therefore, for example, a heat transfer gas such as helium gas is supplied to the space between the back surface of the substrate and the front surface of the electrostatic chuck, and the temperature of the substrate is controlled by controlling the pressure of the heat transfer gas.

[0011] In recent years, in order to achieve even higher precision in substrate temperature control, the space between the backside of the substrate and the surface of the electrostatic chuck has been partitioned into multiple regions, and a pressure difference in the heat transfer gas is established between the regions to control the substrate temperature in each region. Conventionally, to control the pressure of the heat transfer gas in each region, a partition, known as a seal band, that directly contacts the backside of the substrate has been provided on the surface of the electrostatic chuck. For example, the above-mentioned Patent Document 1 discloses a configuration in which multiple sealing bands are provided on the surface of the electrostatic chuck as seal bands. Furthermore, the above-mentioned Patent Document 2 discloses that an inner peripheral ring may be provided on the surface of the electrostatic chuck, inside the outermost peripheral ring.

[0012] However, because the seal band directly contacts the rear surface of the substrate, the contact area becomes a local temperature singularity. Specifically, heat is transferred to the substrate at the contact area, causing the temperature of the substrate at the contact area to drop. The temperature singularity of the substrate affects the rate of plasma processing, and as a result, plasma processing may not be performed uniformly across the substrate surface. Therefore, there is room for improvement in conventional plasma processing.

[0013] The technology disclosed herein has been made in consideration of the above circumstances, and appropriately controls the temperature of a substrate and improves the uniformity of plasma processing within the substrate surface. Hereinafter, a plasma processing apparatus and an electrostatic chuck according to this embodiment will be described with reference to the drawings. Note that in this specification and the drawings, elements having substantially the same functional configurations are designated by the same reference numerals, and redundant description will be omitted.

[0014] <Plasma Processing System> First, a plasma processing system according to one embodiment will be described. Fig. 1 is a diagram illustrating an example of the configuration of the plasma processing system.

[0015] In one embodiment, the plasma processing system includes a plasma processing device 1 and a control unit 2. The plasma processing system is an example of a substrate processing system, and the plasma processing device 1 is an example of a substrate processing device. The plasma processing device 1 includes a plasma processing chamber 10 as a substrate processing chamber, 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 exhaust port for exhausting gas from the plasma processing space. The gas supply port is connected to a gas supply unit 20 (described later), and the gas exhaust port is connected to an exhaust system 40 (described later). The substrate support unit 11 is disposed in the plasma processing space and has a substrate support surface for supporting a substrate.

[0016] The plasma generating unit 12 is configured to generate plasma from at least one processing gas supplied into the plasma processing space. The plasma formed in the plasma processing space may be capacitively coupled plasma (CCP), inductively coupled plasma (ICP), electron-cyclotron-resonance plasma (ECR plasma), helicon wave plasma (HWP), or surface wave plasma (SWP). Various types of plasma generators may be used, including alternating current (AC) plasma generators and direct current (DC) plasma generators. In one embodiment, the AC signal (AC power) used in the AC plasma generator has a frequency in the range of 100 kHz to 10 GHz. Thus, AC signals include radio frequency (RF) signals and microwave signals. In one embodiment, the RF signal has a frequency in the range of 100 kHz to 150 MHz.

[0017] The control unit 2 processes computer-executable instructions that cause the plasma processing apparatus 1 to perform various processes described in this disclosure. The control unit 2 may be configured to control each element of the plasma processing apparatus 1 to perform 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 may include a processing unit 2a1, a storage unit 2a2, and a communication interface 2a3. The control unit 2 may be implemented by, for example, a computer 2a. The processing unit 2a1 may be configured to read a program from the storage unit 2a2 and execute the read program to perform various control operations. This program may be stored in the storage unit 2a2 in advance or may be acquired via a medium when needed. The acquired program is stored in the storage unit 2a2 and read from the storage unit 2a2 by the processing unit 2a1 for execution. The medium may be various storage media readable by the computer 2a or a communication line connected to the communication interface 2a3. The processing unit 2a1 may be a CPU (Central Processing Unit). The storage unit 2a2 may include a random access memory (RAM), a read-only memory (ROM), a hard disk drive (HDD), a solid state drive (SSD), or a combination thereof. The communication interface 2a3 may communicate with the plasma processing apparatus 1 via a communication line such as a local area network (LAN).

[0018] <Plasma Processing Apparatus> A configuration example of a capacitively coupled plasma processing apparatus will be described below as an example of the plasma processing apparatus 1. Fig. 2 is a diagram for explaining a configuration example of a capacitively coupled plasma processing apparatus.

[0019] The capacitively coupled plasma processing apparatus 1 includes a plasma processing chamber 10, a gas supply 20, a power supply 30, and an exhaust system 40. The plasma processing apparatus 1 also includes a substrate support 11 and a gas inlet. The gas inlet is configured to introduce at least one process gas into the plasma processing chamber 10. The gas inlet includes a showerhead 13. The substrate support 11 is disposed within the plasma processing chamber 10. The showerhead 13 is disposed above the substrate support 11. In one embodiment, the showerhead 13 forms at least a portion of the ceiling of the plasma processing chamber 10. The plasma processing chamber 10 has a plasma processing space 10s defined by the showerhead 13, a sidewall 10a of the plasma processing chamber 10, and the substrate support 11. The plasma processing chamber 10 is grounded. The showerhead 13 and the substrate support 11 are electrically insulated from the housing of the plasma processing chamber 10.

[0020] The substrate support 11 includes a support main body 111 and a ring assembly 112. The upper surface of the support main body 111 has a substrate support surface 111a, which is a central region for supporting the substrate W, and a ring support surface 111b, which is an annular region for supporting the ring assembly 112. A wafer is an example of a substrate W. The ring support surface 111b of the support main body 111 surrounds the substrate support surface 111a of the support main body 111 in a plan view. The substrate W is placed on the substrate support surface 111a of the support main body 111, and the ring assembly 112 is placed on the ring support surface 111b of the support main body 111 so as to surround the substrate W on the substrate support surface 111a of the support main body 111.

[0021] In one embodiment, the support body 111 includes a base 113 and an electrostatic chuck 114. The base 113 includes a conductive member. The conductive member of the base 113 may function as a lower electrode. The electrostatic chuck 114 is disposed on the base 113. The electrostatic chuck 114 includes a chuck body 200 and an electrostatic electrode 201 disposed within the chuck body 200. The chuck body 200 has a substrate support surface 111a. In one embodiment, the chuck body 200 also has a ring support surface 111b. Note that another member surrounding the electrostatic chuck 114, such as an annular electrostatic chuck or an annular insulating member, may also have the ring support surface 111b. In this case, the ring assembly 112 may be disposed on the annular electrostatic chuck or the annular insulating member, or may be disposed on both the electrostatic chuck 114 and the annular insulating member. At least one RF / DC electrode coupled to an RF power supply 31 and / or a DC power supply 32 (described later) may be disposed within the chuck body 200. In this case, the at least one RF / DC electrode functions as a lower electrode. When a bias RF signal and / or a DC signal (described later) is supplied to the at least one RF / DC electrode, the RF / DC electrode is also called a bias electrode. Note that the conductive member of the base 113 and the at least one RF / DC electrode may function as multiple lower electrodes. Alternatively, the electrostatic electrode 201 may function as a lower electrode. Therefore, the substrate support 11 includes at least one lower electrode.

[0022] The ring assembly 112 includes one or more annular members. In one embodiment, the one or more annular members include one or more edge rings and at least one cover ring. The edge rings are formed of a conductive or insulating material, and the cover rings are formed of an insulating material.

[0023] The substrate support 11 may also include a temperature adjustment module configured to adjust at least one of the electrostatic chuck 114, the ring assembly 112, and the substrate W to a target temperature. The temperature adjustment module may include a heater, a heat transfer medium, a flow passage 120, or a combination thereof. A heat transfer fluid such as brine or a gas flows through the flow passage 120. In one embodiment, the flow passage 120 is formed in the base 113, and one or more heaters are disposed in the chuck body 200 of the electrostatic chuck 114. The substrate support 11 may also include a heat transfer gas supply unit configured to supply a heat transfer gas to a gap between the back surface of the substrate W and the substrate support surface 111 a.

[0024] The showerhead 13 is configured to introduce at least one process gas from the gas supply unit 20 into the plasma processing space 10s. The showerhead 13 has at least one gas supply port 13a, at least one gas diffusion chamber 13b, and multiple gas inlets 13c. The process gas supplied to the gas supply port 13a passes through the gas diffusion chamber 13b and is introduced into the plasma processing space 10s from the multiple gas inlets 13c. The showerhead 13 also includes at least one upper electrode. In addition to the showerhead 13, the gas inlet may also include one or more side gas injectors (SGIs) attached to one or more openings formed in the sidewall 10a.

[0025] The gas supply unit 20 may include at least one gas source 21 and at least one flow controller 22. In one embodiment, the gas supply unit 20 is configured to supply at least one process gas from a corresponding gas source 21 to the showerhead 13 via a corresponding flow controller 22. Each flow controller 22 may include, for example, a mass flow controller or a pressure-controlled flow controller. Additionally, the gas supply unit 20 may include at least one flow modulation device that modulates or pulses the flow rate of the at least one process gas.

[0026] The power supply 30 includes an RF power supply 31 coupled to the plasma processing chamber 10 via at least one impedance matching circuit. The RF 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 a plasma from at least one processing gas supplied to the plasma processing space 10s. Therefore, the RF power supply 31 can function as at least a part of the plasma generation unit 12. Furthermore, by supplying a bias RF signal to the at least one lower electrode, a bias potential is generated on the substrate W, thereby attracting ion components in the formed plasma to the substrate W.

[0027] In one embodiment, the RF power supply 31 includes a first RF generating unit 31a and a second RF generating unit 31b. The first RF generating unit 31a is coupled to at least one lower electrode and / or at least one upper electrode via at least one impedance matching circuit and is configured to generate a source RF signal (source RF power) for plasma generation. In one embodiment, the source RF signal has a frequency in the range of 10 MHz to 150 MHz. In one embodiment, the first RF generating unit 31a may be configured to generate multiple source RF signals having different frequencies. The generated one or more source RF signals are supplied to at least one lower electrode and / or at least one upper electrode.

[0028] The second RF generator 31b is coupled to at least one lower electrode via at least one impedance matching circuit and is configured to generate a bias RF signal (bias RF power). 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 generator 31b may be configured to generate multiple bias RF signals having different frequencies. The generated one or more bias RF signals are supplied to at least one lower electrode. In various embodiments, at least one of the source RF signal and the bias RF signal may be pulsed.

[0029] The power supply 30 may also include a DC power supply 32 coupled to the plasma processing chamber 10. The DC power supply 32 includes a first DC generator 32a and a second DC generator 32b. In one embodiment, the first DC generator 32a is connected to the at least one lower electrode and configured to generate a first DC signal. The generated first DC signal is applied to the at least one lower electrode. In one embodiment, the second DC generator 32b is connected to the at least one upper electrode and configured to generate a second DC signal. The generated second DC signal is applied to the at least one upper electrode.

[0030] In various embodiments, the first and second DC signals may be pulsed. In this case, a sequence of voltage pulses is applied to at least one lower electrode and / or at least one upper electrode. The voltage pulses may have a rectangular, trapezoidal, triangular, or combination thereof pulse waveform. In one embodiment, a waveform generator for generating the sequence of voltage pulses from the DC signal is connected between the first DC generator 32a and at least one lower electrode. Thus, the first DC generator 32a and the waveform generator constitute a voltage pulse generator. When the second DC generator 32b and the waveform generator constitute a voltage pulse generator, the voltage pulse generator is connected to at least one upper electrode. The voltage pulses may have either positive or negative polarity. Furthermore, the sequence of voltage pulses may include one or more positive voltage pulses and one or more negative voltage pulses within one period. The first and second DC generating units 32a and 32b may be provided in addition to the RF power supply 31, or the first DC generating unit 32a may be provided instead of the second RF generating unit 31b.

[0031] The exhaust system 40 may be connected to, for example, a gas exhaust port 10e provided at the bottom of the plasma processing chamber 10. The exhaust system 40 may include a pressure regulating valve and a vacuum pump. The pressure in the plasma processing space 10s is regulated by the pressure regulating valve. The vacuum pump may include a turbomolecular pump, a dry pump, or a combination thereof.

[0032] <Plasma Processing Method> Next, a plasma processing method performed using the plasma processing system configured as above will be described. As the plasma processing method, for example, an etching process or a film formation process is performed.

[0033] First, a substrate W is loaded into the plasma processing chamber 10 and placed on the electrostatic chuck 114. Thereafter, a DC voltage is applied to the electrostatic electrode 201 of the electrostatic chuck 114, whereby the substrate W is electrostatically attracted to and held on the electrostatic chuck 114 by Coulomb force. At this time, the substrate W is adjusted to a desired temperature. After the substrate W is loaded, the inside of the plasma processing chamber 10 is depressurized to a desired vacuum level by the exhaust system 40.

[0034] Next, a processing gas is supplied from the gas supply unit 20 to the plasma processing space 10s via the shower head 13. Furthermore, the first RF generator 31a of the RF power supply 31 supplies source RF power for plasma generation to the conductive members of the substrate support 11 and / or the conductive members of the shower head 13. The processing gas is then excited to generate plasma. At this time, a bias RF signal for attracting ions may be supplied from the second RF generator 31b. The generated plasma then acts to subject the substrate W to plasma processing.

[0035] First Embodiment Next, the configuration of an electrostatic chuck 114 according to a first embodiment will be described. Fig. 3 is a plan view showing an outline of the configuration of the electrostatic chuck 114. Fig. 4 is a vertical cross-sectional view showing an outline of the configuration of the electrostatic chuck 114. In Fig. 4, C indicates the center line of the electrostatic chuck 114.

[0036] 3 and 4, the electrostatic chuck 114 has a chuck body 200. The chuck body 200 is made of a dielectric material, for example, alumina (Al ２ O ３ The electrostatic chuck 114 is made of ceramics such as SiO 2 . The electrostatic chuck 114 has a substantially disk shape. An electrostatic electrode 201 connected to, for example, a first DC generator 32 a is provided inside the chuck body 200. The first DC generator 32 a applies a DC voltage to the electrostatic electrode 201 to generate Coulomb force, thereby enabling the electrostatic chuck 114 to attract the substrate W. A heater (not shown) may also be provided inside the chuck body 200.

[0037] The upper surface of the chuck body 200 has a substrate support surface 111a for supporting the substrate W. The substrate support surface 111a is formed, for example, in a circular shape having a diameter smaller than that of the supported substrate W. As a result, when the substrate W is supported on the substrate support surface 111a, the outer periphery of the substrate W protrudes outward from the end of the substrate support surface 111a.

[0038] The substrate support surface 111a of the chuck body 200 has substrate contact portions 210 as multiple protrusions and a peripheral contact portion 211 as a peripheral protrusion. The substrate contact portions 210 are cylindrical dots that protrude from the substrate support surface 111a. The multiple substrate contact portions 210 are provided inside the peripheral contact portion 211. The peripheral contact portion 211 is provided in an annular shape at the outermost periphery of the substrate support surface 111a, protruding from the substrate support surface 111a. That is, the peripheral contact portion 211 is arranged to surround a first annular groove 220a, a second annular groove 220b, and an annular protrusion 240, which will be described later. The multiple substrate contact portions 210 and the peripheral contact portion 211 have flat upper surfaces at the same height and come into contact with the substrate W when the substrate W is supported by the electrostatic chuck 114. Therefore, the substrate W is supported by the multiple substrate contact portions 210 and the peripheral contact portion 211.

[0039] At least one annular groove 220, two annular grooves 220a and 220b in this embodiment, are formed in the substrate support surface 111a of the chuck body 200. The annular grooves 220a and 220b are each recessed from the substrate support surface 111a and formed in an annular shape, or in this embodiment, in a circular ring shape. The annular grooves 220a and 220b are arranged radially from the inside to the outside in this order, with the second annular groove 220b surrounding the first annular groove 220a. The center positions of the annular grooves 220a and 220b in a plan view are the same as the center positions of the substrate support surface 111a, i.e., the annular grooves 220a and 220b are arranged on concentric circles.

[0040] The annular grooves 220a and 220b each have a rectangular cross-sectional shape. The annular grooves 220a and 220b have the same cross-sectional shape. In the following description, the annular grooves 220a and 220b may be collectively referred to as the annular groove 220.

[0041] 5, the depth D1 of the annular groove 220 (the depth from the substrate support surface 111a to the bottom of the annular groove 220) is equal to or greater than the height H1 of the substrate contact portion 210 (the height from the substrate support surface 111a to the top surface of the substrate contact portion 210). Furthermore, the depth D2 of the annular groove 220 (the depth from the top surface of the substrate contact portion 210 to the bottom of the annular groove 220) is equal to or greater than twice the height H1 of the substrate contact portion 210. For example, when the height H1 of the substrate contact portion 210 is 5 μm to 20 μm, the depth D2 of the annular groove 220 is 10 μm to 40 μm.

[0042] There are no particular limitations on the upper limits of the depths D1 and D2 of the annular groove 220. For example, the annular groove 220 may extend vertically downward until its bottom does not reach the electrostatic electrode 201 and is positioned slightly above the upper surface of the electrostatic electrode 201. Furthermore, for example, the depth D1 of the annular groove 220 may be equal to or less than half the distance H2 from the upper surface of the substrate contact portion 210 to the upper surface of the electrostatic electrode 201.

[0043] The width E1 (radial length) of the annular groove 220 is, for example, 0.3 mm to 10 mm. The width E1 of the annular groove 220 is not particularly limited.

[0044] 3 and 4 , the first annular groove 220a is formed with at least one first gas supply hole, a first heat transfer gas supply hole 230a. The first heat transfer gas supply hole 230a is formed from the bottom of the first annular groove 220a through the chuck body 200. A first heat transfer gas supply path 231a, which serves as at least one first gas supply path, is connected to the first heat transfer gas supply hole 230a, and the first heat transfer gas supply path 231a is further connected to a heat transfer gas supply source 232. The first heat transfer gas supply path 231a is provided with at least one first control valve 233a and a first pressure gauge 234a on the heat transfer gas supply source 232 side. The aperture of the first control valve 233a is controlled so that the pressure detected by the first pressure gauge 234a becomes a desired pressure. As a result, the first control valve 233a is configured to control the flow rate or pressure of the heat transfer gas supplied from the heat transfer gas supply source 232 via the first heat transfer gas supply path 231a. The first control valve 233a and the first pressure gauge 234a may be provided integrally. The heat transfer gas supplied from the heat transfer gas supply source 232 is supplied to the first annular groove 220a via the first heat transfer gas supply path 231a and the first heat transfer gas supply holes 230a, and diffuses circumferentially along the first annular groove 220a. The heat transfer gas is also supplied to a space between the back surface of the substrate W and the substrate support surface 111a (hereinafter referred to as the "heat transfer space").

[0045] At least one second heat transfer gas supply hole 230b is formed in the second annular groove 220b. The second heat transfer gas supply hole 230b is formed from the bottom of the second annular groove 220b through the chuck body 200. A second heat transfer gas supply path 231b is connected to the second heat transfer gas supply hole 230b, and the second heat transfer gas supply path 231b is connected to a heat transfer gas supply source 232. At least one second control valve 233b and a second pressure gauge 234b are provided in the second heat transfer gas supply path 231b from the heat transfer gas supply source 232 side. The second control valve 233b and the second pressure gauge 234b have the same configurations as the first control valve 233a and the first pressure gauge 234a, respectively, and the second control valve 233b is configured to control the flow rate or pressure of the heat transfer gas. As with the first annular groove 220a, the heat transfer gas supplied from the heat transfer gas supply source 232 through the second heat transfer gas supply path 231b and the second heat transfer gas supply holes 230b diffuses in the circumferential direction along the second annular groove 220b and is also supplied to the heat transfer space.

[0046] In this embodiment, the heat transfer gas supply paths 231a and 231b join together and communicate with the common heat transfer gas supply source 232, but they may each communicate with a separate heat transfer gas supply source. In this embodiment, the flow rate or pressure of the heat transfer gas supplied from the heat transfer gas supply holes 230a and 230b is controlled using the control valves 233a and 233b. Alternatively, the flow rate or pressure of the heat transfer gas may be controlled by changing the diameter of the heat transfer gas supply holes 230a and 230b. The heat transfer gas (backside gas) may be, for example, helium gas. In addition, in the following description, the heat transfer gas supply holes 230a and 230b may be collectively referred to as the heat transfer gas supply holes 230, the heat transfer gas supply paths 231a and 231b may be collectively referred to as the heat transfer gas supply paths 231, the control valves 233a and 233b may be collectively referred to as the control valves 233, and the pressure gauges 234a and 234b may be collectively referred to as the pressure gauges 234.

[0047] As shown in FIGS. 3 to 5 , an annular protrusion 240 that functions as a pressure adjusting section, as described below, is formed on the substrate support surface 111a of the chuck body 200. The annular protrusion 240 is formed in an annular shape, protruding from the substrate support surface 111a and having a circular ring shape in this embodiment. The annular protrusion 240 is disposed between the first annular groove 220a and the second annular groove 220b. The center positions of the annular protrusion 240 in a plan view are the same as the center positions on the substrate support surface 111a. That is, the annular grooves 220a, 220b and the annular protrusion 240 are disposed on concentric circles. The annular protrusion 240 is also disposed at the radial center position between the first annular groove 220a and the second annular groove 220b.

[0048] The annular protrusion 240 has a rectangular shape in a cross-sectional view. The annular protrusion 240 does not contact the substrate W supported by the substrate contact portion 210 of the electrostatic chuck 114. That is, as shown in FIG. 5 , the height H3 of the annular protrusion 240 (the height from the substrate support surface 111a to the upper surface of the annular protrusion 240) is smaller than the height H1 of the substrate contact portion 210 (the height from the substrate support surface 111a to the upper surface of the substrate contact portion 210). The height H3 of the annular protrusion 240 is greater than half the height H1 of the substrate contact portion 210. Therefore, the height H3 of the annular protrusion 240 is set to a range that satisfies the following formula (1). For example, the height H1 of the substrate contact portion 210 is 5 μm to 20 μm, whereas the height H3 of the annular protrusion 240 is 2.5 μm to 10 μm. (H1) / 2<(H3)<(H1) ... (1)

[0049] The width E3 (radial length) of the annular protrusion 240 is smaller than 1 / 3 of the radial distance E2 between the first annular groove 220a and the second annular groove 220b. The width E3 of the annular protrusion 240 is greater than 0.3 mm. Therefore, the width E3 of the annular protrusion 240 is set within a range that satisfies the following formula (2). For example, when the radial distance E2 between the annular grooves 220a and 220b is 15 mm to 90 mm, the width E3 of the annular protrusion 240 is 5 mm to 30 mm. 0.3 mm < (E3) < (E2) / 3 (2)

[0050] The material of the annular protrusion 240 is, for example, the same as that of the chuck body 200, but is not particularly limited to this. Regardless of the material of the annular protrusion 240, the annular protrusion 240 can provide the effect of pressure control in the heat transfer space, which will be described later.

[0051] The annular grooves 220a, 220b and the annular protrusion 240 divide the substrate support surface 111a into seven regions R1 to R7. The first region R1 is a circular region radially inward of the first annular groove 220a. The second region R2 is an annular region in which the first annular groove 220a is formed. The third region R3 is an annular region between the first annular groove 220a and the annular protrusion 240. The fourth region R4 is an annular region in which the annular protrusion 240 is formed. The fifth region R5 is an annular region between the annular protrusion 240 and the second annular groove 220b. The sixth region R6 is an annular region in which the second annular groove 220b is formed. The seventh region R7 is an annular region between the second annular groove 220b and the outer circumferential contact portion 211. In each of the regions R1, R3, R5, and R7, a plurality of the substrate contact portions 210 described above are arranged.

[0052] For example, when the pressures of the heat transfer gas supplied from the heat transfer gas supply holes 230a, 230b are different, the pressure in the heat transfer space is controlled for each of the seven regions R1 to R7. Fig. 5 is an explanatory diagram showing the pressure distribution in the heat transfer spaces of the regions R1 to R7 when the pressure P12 of the heat transfer gas from the second heat transfer gas supply hole 230b (second annular groove 220b) is higher than the pressure P11 from the first heat transfer gas supply hole 230a (first annular groove 220a). In the graph of Fig. 5, the vertical axis represents the pressure in the heat transfer space, and the horizontal axis represents the radial position of the substrate W in a specific direction.

[0053] The heat transfer gas diffuses from the first heat transfer gas supply holes 230a into the heat transfer spaces radially inside the first annular groove 220a, i.e., the heat transfer spaces in the first region R1 and the second region R2. The pressure in the heat transfer spaces in the first region R1 and the second region R2 is substantially equal to the pressure P11 of the heat transfer gas from the first heat transfer gas supply holes 230a.

[0054] The heat transfer gas diffuses from the second heat transfer gas supply holes 230b into the heat transfer spaces radially outside the second annular groove 220b, i.e., the heat transfer spaces in the sixth region R6 and the seventh region R7. The pressure in the heat transfer spaces in the sixth region R6 and the seventh region R7 is substantially equal to the pressure P12 of the heat transfer gas from the second heat transfer gas supply holes 230b.

[0055] As described above, the heat transfer gas diffuses circumferentially along the first annular groove 220a and along the second annular groove 220b. Between the heat transfer space between the first annular groove 220a and the second annular groove 220b, i.e., the heat transfer space of regions R3 to R5, and the heat transfer space of the radially inner regions R1 and R2, gas conductance in the heat transfer space decreases, generating a pressure difference. Similarly, between the heat transfer space of regions R3 to R5 and the heat transfer space of the radially outer regions R6 and R7, gas conductance in the heat transfer space decreases, generating a pressure difference. That is, the pressure in the heat transfer space of regions R3 to R5 changes from P12 to P11 from the outer side to the inner side in the radial direction.

[0056] An annular convex portion 240 is formed in the fourth region R4, and this annular convex portion 240 increases the radial change in pressure in the heat transfer space (hereinafter referred to as the "pressure gradient"). That is, from the outer side to the inner side in the radial direction in regions R3 to R5, the pressure gradient is small in the heat transfer space of the fifth region R5, large in the heat transfer space of the fourth region R4, and small in the heat transfer space of the third region R3.

[0057] As described above, according to this embodiment, a pressure difference can be generated between the heat transfer spaces of regions R3 to R5 and the heat transfer spaces of regions R1 and R2, and a pressure difference can also be generated between the heat transfer spaces of regions R3 to R5 and the heat transfer spaces of regions R6 and R7. As a result, the pressure in the heat transfer spaces of regions R1 to R7 can be controlled, thereby controlling the temperature of the substrate W in each of regions R1 to R7. By forming the annular grooves 220a and 220b and the annular protrusion 240, the pressure difference can be generated without contacting the substrate W, eliminating the local temperature singularities that occur when a seal band contacts the substrate, as occurs in conventional devices. Therefore, according to this embodiment, the temperature controllability of the substrate W can be improved, and the uniformity of the plasma processing within the substrate surface can be improved.

[0058] According to this embodiment, when the substrate support surface 111a is divided into the regions R1 to R7, it does not come into contact with the substrate W, and therefore does not wear out and change shape as in the case of conventional seal bands. Therefore, it is less likely to change over time, and the pressure in the heat transfer spaces of the regions R1 to R7 can be appropriately controlled.

[0059] If the annular convex portion 240 were not provided in the regions R3 to R5, the pressure in the heat transfer space in those regions R3 to R5 would have a constant pressure gradient from the radial outer side to the radial inner side. In this regard, according to the present embodiment, the annular convex portion 240 is formed in the fourth region R4 in the regions R3 to R5. This allows the flow of heat transfer gas to be changed in the annular convex portion 240, thereby increasing the pressure gradient in the heat transfer space in the fourth region R4. In other words, a steep pressure change can be achieved in the fourth region R4. Therefore, the radial pressure distribution in the heat transfer space can be controlled more precisely. As a result, the temperature controllability of the substrate W can be further improved, and the uniformity of the plasma processing within the substrate surface can be further improved.

[0060] Moreover, since there is no need to form an annular groove 220 similar to the annular grooves 220a and 220b in the regions R3 to R5, there is no need for a supply system such as the heat transfer gas supply path 231, control valve 233, pressure gauge 234, etc. for supplying a heat transfer gas to the annular groove 220. Therefore, the temperature controllability of the substrate W can be improved with the simple structure of forming the annular convex portion 240.

[0061] Furthermore, according to this embodiment, the heat transfer gas is diffused in the circumferential direction in the annular grooves 220a and 220b, so that the temperature uniformity in the circumferential direction of the substrate W can also be improved.

[0062] Furthermore, according to this embodiment, an outer peripheral contact portion 211 that comes into contact with the substrate W is provided at the outermost periphery of the substrate support surface 111a, so that even if heat transfer gas is supplied to the heat transfer space radially inside the outer peripheral contact portion 211, the heat transfer gas can be prevented from flowing out of the heat transfer space.

[0063] 3 to 5, the annular protrusion 240 is disposed at the radial center between the first annular groove 220a and the second annular groove 220b, but the position of the annular protrusion 240 is not limited to this. The position of the annular protrusion 240 can be set arbitrarily depending on the required pressure gradient, i.e., temperature gradient.

[0064] Furthermore, in the above embodiment shown in Figures 3 to 5, a case was described in which two annular grooves 220a, 220b and one annular protrusion 240 are formed on the substrate support surface 111a of the chuck main body 200, but the number and arrangement of these annular grooves 220 and annular protrusions 240 are not limited to this.

[0065] 6, the substrate support surface 111a may be formed with four annular grooves 220a, 220b, 220c, and 220d and three annular protrusions 240a, 240b, and 240c. The annular grooves 220a, 220b, 220c, and 220d and the annular protrusions 240a, 240b, and 240c are arranged concentrically.

[0066] The annular grooves 220a, 220b, 220c, and 220d are arranged radially from the inside to the outside in this order. Heat transfer gas supply holes 230a, 230b, 230c, and 230d are formed in the annular grooves 220a, 220b, 220c, and 220d, respectively, and are further connected to heat transfer gas supply paths 231a, 231b, 231c, and 231d. The heat transfer gas supply paths 231a, 231b, 231c, and 231d are provided with control valves 233a, 233b, 233c, and 233d (not shown) and pressure gauges 234a, 234b, 234c, and 234d (not shown), respectively.

[0067] The first annular protrusion 240a is disposed between the first annular groove 220a and the second annular groove 220b. The second annular protrusion 240b is disposed between the second annular groove 220b and the third annular groove 220c. The third annular protrusion 240c is disposed between the third annular groove 220c and the fourth annular groove 220d. As described above, the height H3 of each annular protrusion 240a, 240b, 240c satisfies the following formula (1) with respect to the height H1 of the substrate contact portion 210. Furthermore, the width E3 of each annular protrusion 240a, 240b, 240c satisfies the following formula (2) with respect to the radial distance E2 between the annular grooves 220. (H1) / 2<(H3)<(H1) ... (1) 0.3 mm<(E3)<(E2) / 3 ... (2)

[0068] As another example, four annular grooves 220a, 220b, 220c, and 220d and four annular protrusions 240a, 240b, 240c, and 240d may be formed on the substrate support surface 111a as shown in Fig. 7. In the example shown in Fig. 7, a plurality of, for example, two second annular protrusions 240b and three third annular protrusions 240c are arranged between the second annular groove 220b and the third annular groove 220c in the example shown in Fig. 6.

[0069] As described above, the height H3 of each annular protrusion 240a, 240b, 240c, and 240d satisfies the following formula (1) relative to the height H1 of the substrate contact portion 210. Furthermore, the width E3 of the first annular protrusion 240a and the fourth annular protrusion 240d satisfies the following formula (2) relative to the radial distance E2 between the annular grooves 220. Meanwhile, the sum of the width E4 of the second annular protrusion 240b and the width E5 of the third annular protrusion 240c satisfies the following formula (2), i.e., the following formula (2'). Even when a plurality of annular protrusions 240b and 240c are provided between the annular grooves 220b and 220c, the above-described effects can be achieved and the pressure in the heat transfer space between the annular grooves 220b and 220c can be appropriately controlled as long as the widths E4 and E5 of these annular protrusions 240b and 240c satisfy the following formula (2'). (H1) / 2<(H3)<(H1)...(1) 0.3mm<(E3)<(E2) / 3...(2) 0.3mm<(E3)=(E4+E5)<(E2) / 3...(2')

[0070] Next, a simulation related to this embodiment will be described. In this simulation, as an example, the model shown in Fig. 6 was used, i.e., a model in which annular grooves 220a, 220b, 220c, and 220d and annular protrusions 240a, 240b, and 240c were formed on the substrate support surface 111a. As a comparative example, a model in the example shown in Fig. 6 was used in which the annular protrusions 240a, 240b, and 240c were not formed on the substrate support surface 111a, and only the annular grooves 220a, 220b, 220c, and 220d were formed.

[0071] 8 is an explanatory diagram showing the pressure in the heat transfer space above the substrate W in the case where the pressure P22 of the heat transfer gas in the third annular groove 220c is higher than the pressure P21 of the heat transfer gas in the other annular grooves 220a, 220b, and 220d in this simulation. In FIG. 8, the vertical axis indicates the pressure in the heat transfer space, and the horizontal axis indicates the radial position of the substrate W in a specific direction.

[0072] 8, in the comparative example, the pressure gradient in the heat transfer space between annular grooves 220b and 220c is approximately constant, and the pressure gradient in the heat transfer space between annular grooves 220c and 220d is also approximately constant. Therefore, it was not possible to appropriately control the pressure gradient in the heat transfer space in the regions of these annular grooves 220b to 220d.

[0073] On the other hand, in the embodiment, the pressure gradient in the heat transfer space is small between the second annular groove 220 b and the second annular convex portion 240 b and between the third annular groove 220 c and the second annular convex portion 240 b, while the pressure gradient in the heat transfer space is large at the second annular convex portion 240 b. Therefore, a steep pressure change can be applied to the second annular convex portion 240 b.

[0074] Similarly, in the embodiment, the pressure gradient in the heat transfer space is small between the third annular groove 220 c and the third annular protrusion 240 c and between the fourth annular groove 220 d and the third annular protrusion 240 c, while the pressure gradient in the heat transfer space is large at the third annular protrusion 240 c. Therefore, a steep pressure change can be applied at the third annular protrusion 240 c.

[0075] In addition, in the example, compared to the comparative example, the maximum value of the pressure in the heat transfer space in the third annular groove 220c is larger. This is because forming the second annular convex portion 240b and the third annular convex portion 240c makes it easier to create a pressure difference across the entire region of the annular grooves 220b to 220d, resulting in a larger pressure difference between the high and low pressures. From this perspective, the example allows for appropriate control of the pressure in the heat transfer space.

[0076] 9 is an explanatory diagram showing the pressure in the heat transfer space above the substrate W in this simulation when the heat transfer gas pressure P23 in the third annular groove 220c is lower than the heat transfer gas pressure P21 in the other annular grooves 220a, 220b, and 220d. Even in this case, the same results as those shown in FIG.

[0077] 9, in the comparative example, the pressure gradient in the heat transfer space between annular grooves 220b and 220c is approximately constant, and the pressure gradient in the heat transfer space between annular grooves 220c and 220d is also approximately constant. Therefore, it was not possible to sharply control the pressure gradient in the heat transfer space in the regions of these annular grooves 220b to 220d.

[0078] On the other hand, in the embodiment, the pressure gradient in the heat transfer space is small between the second annular groove 220 b and the second annular convex portion 240 b and between the third annular groove 220 c and the second annular convex portion 240 b, while the pressure gradient in the heat transfer space is large at the second annular convex portion 240 b. Therefore, a steep pressure change can be applied to the second annular convex portion 240 b.

[0079] Similarly, in the embodiment, the pressure gradient in the heat transfer space is small between the third annular groove 220 c and the third annular protrusion 240 c and between the fourth annular groove 220 d and the third annular protrusion 240 c, while the pressure gradient in the heat transfer space is large at the third annular protrusion 240 c. Therefore, a steep pressure change can be applied at the third annular protrusion 240 c.

[0080] As described above, the simulation results also demonstrate that the effects of this embodiment can be achieved. That is, according to this embodiment, the pressure in the heat transfer space can be controlled depending on the position of the annular protrusion 240, whether the annular protrusion 240 is formed on the high-pressure side or the low-pressure side.

[0081] The pressure gradient in the heat transfer space in the region where the annular protrusion 240 is formed can be controlled by the height H3 and width E3 of the annular protrusion 240.

[0082] For example, when the height H3 of the annular convex portion 240 is large, the pressure gradient in the heat transfer space at the annular convex portion 240 increases. However, since the annular convex portion 240 is formed so as not to contact the substrate W, the height H3 of the annular convex portion 240 is smaller than the height H1 of the substrate contact portion 210, as shown in the following formula (1).

[0083] On the other hand, when the height H3 of the annular protrusion 240 is small, the pressure gradient in the heat transfer space at the annular protrusion 240 becomes small. In this regard, when the above simulation was performed by changing the height H3 of the annular protrusion 240, it was found that when the height H3 of the annular protrusion 240 is greater than half the height H1 of the substrate contact portion 210, as shown in the following formula (1), the effect of the annular protrusion 240 described above, that is, the effect of being able to control the pressure gradient in the heat transfer space at the annular protrusion 240 to be sufficiently large, can be enjoyed. (H1) / 2<(H3)<(H1) ... (1)

[0084] Figure 10 is an explanatory diagram showing the pressure distribution in the heat transfer space in the second annular convex portion 240b when the width E3 of the second annular convex portion 240b is varied between width E31 and width E32 in the simulation shown in Figure 8 above.

[0085] 10 , when the width E3 of the second annular convex portion 240b is large, i.e., width E31, the pressure gradient in the heat transfer space in the second annular convex portion 240b is small. However, the area where the pressure changes is large. In this regard, it has been found that when the width E31 (width E3) of the second annular convex portion 240b is smaller than one-third of the radial distance E2 between the annular grooves 220, as shown in the following formula (2), the above-mentioned effect of the second annular convex portion 240b, i.e., the effect of being able to control the pressure gradient in the heat transfer space of the second annular convex portion 240b to a sufficiently large value, can be achieved.

[0086] On the other hand, when the width E3 of the second annular convex portion 240b is small, i.e., width E32, the pressure gradient in the heat transfer space in the second annular convex portion 240b becomes large. However, the area where the pressure changes becomes small. In this regard, it has been found that when the width E32 (width E3) of the second annular convex portion 240b is larger than 0.3 mm, as shown in the following formula (2), the above-mentioned effect of the second annular convex portion 240b can be obtained. 0.3 mm<(E3)<(E2) / 3 (2)

[0087] The pressure gradient in the heat transfer space in the annular convex portion 240 is determined according to the specifications required for the substrate W. The height H3 of the annular convex portion 240 is determined within a range that satisfies the above formula (1), and the width E3 of the annular convex portion 240 is determined within a range that satisfies the above formula (2).

[0088] 6 , the plurality of substrate contact portions 210 may be provided on the upper surface of the annular convex portion 240, as shown in FIGS. 11 and 12 . A simulation was performed to compare the case where the substrate contact portions 210 are provided on the upper surface of the annular convex portion 240 with the case where the substrate contact portions 210 are not provided. As a result, the pressure gradient in the heat transfer space in the annular convex portion 240 was found to be approximately the same. In this way, when the substrate contact portions 210 are provided on the upper surface of the annular convex portion 240, the substrate W can be appropriately supported by the substrate contact portions 210 even when, for example, the width E3 of the annular convex portion 240 is large.

[0089] Second Embodiment Next, a configuration of an electrostatic chuck 114 according to a second embodiment will be described. In the second embodiment, as shown in FIG. 13 , an annular adjacent groove 250 is formed in the substrate support surface 111 a so as to be adjacent to the annular protrusion 240.

[0090] 6 , for example, a first inner adjacent groove 250a1 is formed on the radially inner side of the first annular convex portion 240a, and a first outer adjacent groove 250a2 is formed on the radially outer side of the first annular convex portion 240a. Similarly, inner adjacent grooves 250b1 and 250c1 and outer adjacent grooves 250b2 and 250c2 are formed on the radially inner and outer sides of the annular convex portions 240b and 240c, respectively. In the following description, the adjacent grooves 250a1, 250a2, 250b1, 250b2, 250c1, and 250c2 may be collectively referred to as adjacent grooves 250.

[0091] The depth of the adjacent groove 250 (the depth from the substrate support surface 111a to the bottom of the adjacent groove 250) is, for example, the same as the depth D1 of the annular groove 220. The width (radial length) of the adjacent groove 250 is not particularly limited, but is, for example, 0.5 mm. In this case, the controllability of the pressure in the heat transfer space by the annular protrusion 240 can be improved.

[0092] 14 is an explanatory diagram showing the pressure in the heat transfer space above the substrate W in a simulation using the model shown in FIG. 13 when the heat transfer gas pressure P22 in the third annular groove 220c is higher than the heat transfer gas pressure P21 in the other annular grooves 220a, 220b, and 220d. That is, the heat transfer gas pressure conditions in this simulation are the same as the heat transfer space pressure conditions in the simulation shown in FIG. 8 (the simulation using the model shown in FIG. 6). In the following description, the simulation using the model shown in FIG. 6 will be referred to as Example 1, and the simulation using the model shown in FIG. 13 of this example will be referred to as Example 2. Note that the comparative example, like the simulation shown in FIG. 8, is a simulation using a model in which the annular convex portions 240a, 240b, and 240c are not formed on the substrate support surface 111a, and only the annular grooves 220a, 220b, 220c, and 220d are formed.

[0093] 14A, the pressure gradient in the heat transfer space is smaller in Example 2 than in Example 1 at the radially inner side of the second annular convex portion 240b, as shown in FIG. 14A. In other words, the second inner adjacent groove 250b1 increases the heat transfer gradient in the heat transfer space at the second annular convex portion 240b. Also, as shown in FIG. 14B, the pressure gradient in the heat transfer space is smaller in Example 2 than in Example 1 at the radially outer side of the second annular convex portion 240b. In other words, the second outer adjacent groove 250b2 increases the heat transfer gradient in the heat transfer space at the second annular convex portion 240b. As described above, the adjacent grooves 250b1 and 250b2 can improve the controllability of the pressure in the heat transfer space at the second annular convex portion 240b.

[0094] Here, when the pressure in the heat transfer space is controlled using a seal band that contacts the back surface of the substrate, as in the conventional method, the heat transfer space is separated on the radially inner and outer sides of the seal band, so the pressure change in the heat transfer space at the seal band becomes rectangular. In contrast, when the adjacent groove 250 is formed adjacent to the annular convex portion 240 as in this embodiment, the pressure change in the heat transfer space becomes closer to a rectangle, as shown in Figure 14. From this perspective, it can be seen that the adjacent groove 250 can improve the controllability of the pressure in the heat transfer space at the annular convex portion 240.

[0095] Furthermore, by forming an annular adjacent groove 250 arranged adjacent to the annular protrusion 240, the heat transfer gas diffuses in the circumferential direction in the adjacent groove 250, thereby improving the circumferential uniformity of the pressure in the heat transfer space.

[0096] In order to obtain the effect of improving pressure controllability by the adjacent groove 250, the depth of the adjacent groove 250 may be larger than the depth D1 of the annular groove 220. In order to obtain this effect, it is preferable that the aspect ratio of the adjacent groove 250 is large.

[0097] In the above embodiment, the adjacent grooves 250 are formed on the radially inner and outer sides of all of the annular protrusions 240, but the number of adjacent grooves 250 is not limited to this. For example, the adjacent grooves 250 may be formed on either the radially inner or outer side of the annular protrusions 240. Furthermore, for example, the adjacent grooves 250 may be formed adjacent to any of the annular protrusions 240.

[0098] Third Embodiment Next, a configuration of an electrostatic chuck 114 according to a third embodiment will be described. In the third embodiment, an intermediate groove 260 that functions as a pressure adjusting groove is formed in the substrate support surface 111 a as shown in FIG.

[0099] 6, for example, the intermediate groove 260 is formed in place of the first annular convex portion 240a. That is, the intermediate groove 260, the second annular convex portion 240b, the third annular convex portion 240c, and the annular grooves 220a, 220b, 220c, and 220d are formed on the substrate support surface 111a.

[0100] The intermediate groove 260 is recessed from the substrate support surface 111a and has an annular shape, which in this embodiment is a circular ring shape. The intermediate groove 260 has a rectangular shape in cross section. As shown in FIG. 16 , the depth D3 of the intermediate groove 260 (the depth from the upper surface of the substrate contact portion 210 to the bottom of the intermediate groove 260) is smaller than the depth D2 of the annular groove 220 (the depth from the upper surface of the substrate contact portion 210 to the bottom of the annular groove 220). For example, when the height H1 of the substrate contact portion 210 is 5 μm to 20 μm, the depth D3 of the intermediate groove 260 is 10 μm to 30 μm.

[0101] The width E6 of the intermediate groove 260 is equal to or greater than the width E1 of the annular groove 220. For example, the width E6 of the intermediate groove 260 is 10 mm to 50 mm. However, the width E6 of the intermediate groove 260 is not particularly limited.

[0102] The seven regions R1 to R7 in Fig. 16 are the same as the seven regions R1 to R7 shown in Fig. 5. However, the fourth region R4 is an annular region in which the intermediate groove 260 is formed. The graph in Fig. 16 is the same as the graph shown in Fig. 5, and shows the pressure in the heat transfer space of the regions R1 to R7 when the pressure P12 of the heat transfer gas from the second heat transfer gas supply hole 230b is higher than the pressure P11 from the first heat transfer gas supply hole 230a.

[0103] The pressure in the heat transfer space in the first region R1 and the second region R2 is substantially equal to the pressure P11 of the heat transfer gas from the first heat transfer gas supply hole 230a. Similarly, the pressure in the heat transfer space in the sixth region R6 and the seventh region R7 is substantially equal to the pressure P12 of the heat transfer gas from the second heat transfer gas supply hole 230b. Furthermore, the pressure in the heat transfer space in the regions R3 to R5 changes from P12 to P11 from the outer side to the inner side in the radial direction.

[0104] An intermediate groove 260 is formed in the fourth region R4, and the pressure gradient in the heat transfer space is small or substantially constant due to this intermediate groove 260. That is, in regions R3 to R5, from the outer side to the inner side in the radial direction, the pressure gradient is large in the heat transfer space of the fifth region R5, the pressure gradient is small in the heat transfer space of the fourth region R4, and the pressure gradient is large in the heat transfer space of the third region R3.

[0105] As described above, according to this embodiment, in the regions R3 to R5, the intermediate groove 260 is formed in the fourth region R4, so that the flow of the heat transfer gas can be changed in the intermediate groove 260, and the pressure gradient in the heat transfer space can be reduced in the fourth region R4. Therefore, the radial pressure distribution in the heat transfer space can be controlled more precisely. As a result, the temperature controllability of the substrate W can be further improved, and the uniformity of the plasma processing within the substrate surface can be further improved.

[0106] The pressure gradient in the heat transfer space in the fourth region R4 can be controlled by the depth D3 of the intermediate groove 260. For example, if the depth D3 of the intermediate groove 260 is large, the pressure gradient in the heat transfer space in the fourth region R4 will be small. On the other hand, for example, if the depth D3 of the intermediate groove 260 is small, the pressure gradient in the heat transfer space in the fourth region R4 will be large. The pressure gradient in the heat transfer space in the fourth region R4 and the depth D3 of the intermediate groove 260 are determined according to the specifications required for the substrate W.

[0107] Furthermore, when the depth D3 of the intermediate groove 260 is approximately half the depth D2 of the annular groove 220, as in this embodiment, it has been found that the effect of the intermediate groove 260 described above, i.e., the effect of being able to control the pressure gradient in the heat transfer space of the fourth region R4 to be sufficiently small, can be exerted.

[0108] Furthermore, in this embodiment, the depth D3 of the intermediate groove 260 is smaller than the depth D2 of the annular groove 220, but the depth D3 of the intermediate groove 260 and the depth D2 of the annular groove 220 may be the same. Even in such a case, the above-mentioned effect, i.e., the effect of being able to control the pressure gradient in the heat transfer space of the fourth region R4, can be obtained. Note that, although there is no particular upper limit for the depth D3 of the intermediate groove 260, if the added depth D3 is too large, there is a concern that abnormal discharge may occur, so it is preferable to set the depth D3 to a level that can suppress such abnormal discharge.

[0109] The pressure gradient in the heat transfer space of the fourth region R4 is also affected by the width E6 of the intermediate groove 260. For example, when the width E6 of the intermediate groove 260 is small, the pressure gradient in the heat transfer space of the fourth region R4 is large. On the other hand, when the width E6 of the intermediate groove 260 is large, the pressure gradient in the heat transfer space of the fourth region R4 is small.

[0110] In the above embodiment, the intermediate groove 260 is formed in place of the first annular protrusion 240a, but the number and arrangement of the intermediate grooves 260 are not limited to this. For example, the intermediate groove 260 may be formed in place of either or both of the second annular protrusion 240b and the third annular protrusion 240c. Furthermore, for example, a plurality of intermediate grooves 260 may be formed between the annular grooves 220.

[0111] Fourth Embodiment Next, a configuration of an electrostatic chuck 114 according to a fourth embodiment will be described. In the fourth embodiment, a seal band 270 is formed on the substrate support surface 111a as shown in FIG.

[0112] 6, the seal band 270 is formed in place of the third annular convex portion 240c. That is, the seal band 270, the first annular convex portion 240a, the second annular convex portion 240b, and the annular grooves 220a, 220b, 220c, and 220d are formed on the substrate support surface 111a.

[0113] The seal band 270 is provided in an annular shape and protrudes from the substrate support surface 111a. The seal band 270 has a flat upper surface, which comes into contact with the substrate W when the substrate W is supported by the electrostatic chuck 114.

[0114] This separates the heat transfer spaces on the radially inner and outer sides of the seal band 270, making it possible to increase the pressure gradient in the heat transfer space and provide a more rapid pressure change by the seal band 270. Therefore, the seal band 270 is useful when, for example, it is particularly desired to improve the controllability of the pressure in the heat transfer space.

[0115] In the above embodiment, the seal band 270 is formed in place of the third annular protrusion 240c, but the number and arrangement of the seal bands 270 are not limited to this. For example, the seal band 270 may be formed in place of either or both of the first annular protrusion 240a and the second annular protrusion 240b.

[0116] Fifth Embodiment The first to fourth embodiments may be combined. That is, in addition to the annular convex portion 240, at least one of the adjacent groove 250, the intermediate groove 260, and the seal band 270 may be formed on the substrate support surface 111a. These combinations can be set as desired depending on the pressure control required for the process performed in the plasma processing apparatus 1.

[0117] Sixth Embodiment In the above embodiments, the annular convex portion 240 has a rectangular shape in cross section and is formed in a circular ring shape in plan view, but the shape of the annular convex portion 240 is not limited to this.

[0118] For example, as shown in Fig. 18, the annular protrusion 240 may have a trapezoidal shape tapering downward in cross section. Alternatively, as shown in Fig. 19, the annular protrusion 240 may have a semicircular shape with an upper curve in cross section.

[0119] For example, as shown in Fig. 20, the annular protrusion 240 may have a polygonal shape, such as a hexagonal shape, in a planar view. Furthermore, as shown in Fig. 21, the annular protrusion 240 may have a planar shape other than a circular ring shape in a planar view. Furthermore, the multiple annular protrusions 240 may have different central positions in a planar view, and may have a centro-asymmetric shape.

[0120] Furthermore, although the annular protrusion 240 has a continuous annular shape in a plan view, it may have a discontinuous portion. In this case, the annular protrusion 240 may be discontinuous at one location or at multiple locations. In this way, the annular protrusion 240 may be composed of multiple segments divided in the circumferential direction, as long as the annular protrusion 240 is formed in an annular shape as a whole.

[0121] As described above, regardless of the shape of the annular convex portion 240, the same effect as in the above embodiment can be obtained, that is, the pressure gradient in the heat transfer space in the annular convex portion 240 can be controlled.

[0122] The embodiments disclosed herein should be considered to be illustrative in all respects and not restrictive. The above-described embodiments may be omitted, substituted, or modified in various ways without departing from the scope and spirit of the appended claims. For example, the components of the above-described embodiments may be arbitrarily combined. Such an arbitrary combination naturally provides the functions and effects of each of the components involved in the combination, and also provides other functions and effects that are apparent to those skilled in the art from the description of this specification.

[0123] Furthermore, the effects described herein are merely descriptive or exemplary and are not limiting. In other words, the technology according to the present disclosure may achieve other effects that are apparent to those skilled in the art from the description of this specification, in addition to or in place of the above-described effects.

[0124] Note that the following configuration examples also fall within the technical scope of the present disclosure. (1) A substrate processing chamber; a substrate support disposed within the substrate processing chamber, the substrate support having at least one first gas supply line and at least one second gas supply line, the electrostatic chuck being disposed on the base and having an upper surface, the upper surface being formed with: a plurality of protrusions; a first annular groove; a second annular groove surrounding the first annular groove; and an annular convex portion disposed between the first annular groove and the second annular groove, protruding from the upper surface and lower than the protrusions, the first annular groove communicating with the at least one first gas supply line through at least one first gas supply hole, and the second annular groove communicating with the at least one second gas supply line through at least one second gas supply hole; the substrate support having: a base; and at least one second control valve configured to control a flow rate or a pressure of the gas supplied through the at least one second gas supply path. (2) The substrate processing apparatus according to (1), wherein the height of the annular convex portion is greater than half the height of the protrusion. (3) The substrate processing apparatus according to (1) or (2), wherein the width of the annular convex portion is smaller than one-third of the radial distance between the first annular groove and the second annular groove. (4) The substrate processing apparatus according to any of (1) to (3), wherein a plurality of the annular convex portions are arranged between the first annular groove and the second annular groove. (5) The substrate processing apparatus according to any of (1) to (4), wherein the annular convex portion is provided with the plurality of protrusions. (6) The substrate processing apparatus according to any of (1) to (5), wherein an annular adjacent groove arranged adjacent to the annular convex portion is formed on the upper surface at least one of the radial inner side and the radial outer side of the annular convex portion. (7) The substrate processing apparatus according to any one of (1) to (6), wherein an annular intermediate groove is formed on the upper surface, the intermediate groove being located between the first annular groove and the second annular groove and being shallower than the first annular groove and the second annular groove.(8) The substrate processing apparatus according to any one of (1) to (8), wherein the upper surface has annular peripheral protrusions surrounding the first annular groove and the second annular groove. (9) An electrostatic chuck comprising a chuck body having an upper surface, at least one first gas supply line and at least one second gas supply line, wherein the upper surface is formed with: a plurality of protrusions; a first annular groove; a second annular groove surrounding the first annular groove; and an annular convex portion disposed between the first annular groove and the second annular groove, protruding from the upper surface and lower than the protrusions, wherein the first annular groove communicates with the at least one first gas supply line through at least one first gas supply hole, and the second annular groove communicates with the at least one second gas supply line through at least one second gas supply hole. (10) The electrostatic chuck according to (9), wherein the height of the annular convex portion is greater than half the height of the protrusions. (11) The electrostatic chuck according to (9) or (10), wherein the width of the annular convex portion is smaller than one-third of the radial distance between the first annular groove and the second annular groove. (12) The electrostatic chuck according to any one of (9) to (11), wherein a plurality of the annular convex portions are arranged between the first annular groove and the second annular groove. (13) The electrostatic chuck according to any one of (9) to (12), wherein the annular convex portion is provided with the plurality of protrusions. (14) The electrostatic chuck according to any one of (9) to (13), wherein the upper surface is formed with an annular adjacent groove arranged adjacent to the annular convex portion on at least one of the radial inner side and the radial outer side of the annular convex portion. (15) The electrostatic chuck according to any one of (9) to (14), wherein the upper surface is formed with an annular intermediate groove arranged between the first annular groove and the second annular groove and shallower than the first annular groove and the second annular groove. (16) The electrostatic chuck according to any one of (9) to (15), wherein the upper surface has an annular outer peripheral protrusion surrounding the first annular groove and the second annular groove.

[0125] REFERENCE SIGNS LIST 1 Plasma processing apparatus 10 Plasma processing chamber 11 Substrate support portion 111a Substrate support surface 113 Base 114 Electrostatic chuck 210 Substrate contact portion 220a First annular groove 220b Second annular groove 230a First heat transfer gas supply hole 230b Second heat transfer gas supply hole 231a First heat transfer gas supply path 231b Second heat transfer gas supply path 233a First control valve 233b Second control valve 240 Annular convex portion

Claims

1. A substrate processing apparatus, comprising: a substrate processing chamber; a substrate support disposed within the substrate processing chamber and having at least one first gas supply passage and at least one second gas supply passage; a base; an electrostatic chuck disposed on the base and having an upper surface, the upper surface being formed with a plurality of protrusions, a first annular groove, a second annular groove surrounding the first annular groove, and an annular convex portion disposed between the first annular groove and the second annular groove, protruding from the upper surface and lower than the protrusions; the first annular groove communicating with the at least one first gas supply passage through at least one first gas supply hole; the second annular groove communicating with the at least one second gas supply passage through at least one second gas supply hole; the electrostatic chuck; a substrate support; at least one first control valve configured to control the flow rate or pressure of a gas supplied through the at least one first gas supply passage; and at least one second control valve configured to control the flow rate or pressure of a gas supplied through the at least one second gas supply passage.

2. The substrate processing apparatus according to claim 1, wherein the height of the annular convex portion is greater than half the height of the protrusions.

3. The substrate processing apparatus according to claim 1, wherein the width of the annular convex portion is less than 1 / 3 of the radial distance between the first annular groove and the second annular groove.

4. The substrate processing apparatus according to claim 1, wherein a plurality of the annular convex portions are arranged between the first annular groove and the second annular groove.

5. The substrate processing apparatus according to claim 1, wherein the plurality of protrusions are provided on the annular convex portion.

6. The substrate processing apparatus according to claim 1, wherein an annular adjacent groove is formed on the upper surface adjacent to the annular convex portion on at least one of the inner and outer radial sides of the annular convex portion.

7. The substrate processing apparatus according to claim 1, wherein an annular intermediate groove is formed on the upper surface between the first annular groove and the second annular groove and shallower than the first annular groove and the second annular groove.

8. The substrate processing apparatus according to claim 1, wherein the upper surface has an annular outer peripheral protrusion surrounding the first annular groove and the second annular groove.

9. A chuck body having an upper surface, at least one first gas supply passage, and at least one second gas supply passage, wherein the upper surface is formed with a plurality of protrusions, a first annular groove, a second annular groove surrounding the first annular groove, and an annular convex portion disposed between the first annular groove and the second annular groove, protruding from the upper surface and lower than the protrusions, the first annular groove communicating with the at least one first gas supply passage through at least one first gas supply hole, and the second annular groove communicating with the at least one second gas supply passage through at least one second gas supply hole, an electrostatic chuck.

10. The electrostatic chuck according to claim 9, wherein the height of the annular convex portion is greater than half of the height of the protrusions.

11. The electrostatic chuck according to claim 9, wherein the width of the annular convex portion is less than 1 / 3 of the radial distance between the first annular groove and the second annular groove.

12. The electrostatic chuck according to claim 9, wherein a plurality of the annular convex portions are arranged between the first annular groove and the second annular groove.

13. The electrostatic chuck according to claim 9, wherein the plurality of protrusions are provided on the annular convex portion.

14. The electrostatic chuck according to claim 9, wherein an annular adjacent groove is formed on the upper surface adjacent to the annular convex portion on at least one of the radially inner side and the radially outer side of the annular convex portion.

15. The electrostatic chuck according to claim 9, wherein an annular intermediate groove is formed on the upper surface between the first annular groove and the second annular groove and shallower than the first annular groove and the second annular groove.

16. The electrostatic chuck according to claim 9, wherein the upper surface has an annular outer peripheral protrusion surrounding the first annular groove and the second annular groove.

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