Electrostatic Chuck Device

Abstract

To provide an electrostatic chuck device in which an electric field strength distribution in a substrate plane is improved.SOLUTION: An electrostatic chuck device comprises: an electrostatic chuck plate including a dielectric substrate, a suction electrode, and a high frequency electrode; a metal base; and a focus ring. The electrostatic chuck plate is divided into a first region that supports the substrate in a plan view, and a second region having a ring mounting surface onto which the focus ring is mounted. The high frequency electrode includes: a first high frequency electrode arranged in the first region; and a second high frequency electrode arranged in the second region. The focus ring includes an inner peripheral end surface opposite to an external peripheral end surface of the substrate in a horizontal direction in a state where the substrate is mounted onto the mounting surface. An end edge of the inner peripheral side of the second high frequency electrode is positioned between the external peripheral end surface of the substrate, and the inner peripheral end surface of the focus ring in the plan view.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to an electrostatic chuck device. [Background technology]

[0002] As an electrostatic chuck device for supporting a substrate such as a semiconductor wafer, an electrostatic chuck device having a focus ring disposed to surround the substrate is known, as described in Patent Document 1. Also, as described in Patent Document 2, an electrostatic chuck device having an electrode configuration for controlling the ion energy density distribution within the substrate surface is known. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2017-050468 [Patent Document 2] Japanese Patent Application Laid-Open No. 2011-119654 Summary of the Invention [Problem to be solved by the invention]

[0004] By placing a focus ring around the periphery of the substrate, it is possible to reduce variations in the ion incident angle around the periphery of the substrate. However, providing a focus ring places restrictions on the electrode structure around the periphery of the substrate, which can lead to uneven electric field strength around the periphery of the substrate.

[0005] An object of the present invention is to provide an electrostatic chuck device with an improved electric field strength distribution within the surface of a substrate. [Means for solving the problem]

[0006] According to one aspect of the present invention, there is provided an electrostatic chuck device including: a dielectric substrate having a mounting surface on which a substrate is mounted; an electrostatic chuck plate having an attraction electrode located inside the dielectric substrate and a radio-frequency electrode for applying a radio-frequency voltage to the substrate; a metal base supporting the electrostatic chuck plate from a back surface opposite the mounting surface; and a focus ring disposed on the outer periphery of the electrostatic chuck plate and surrounding the mounting surface. The electrostatic chuck plate is partitioned, in a plan view, into a first region for supporting the substrate and a second region surrounding the first region and having a ring mounting surface on which the focus ring is mounted. The radio-frequency electrode includes a first radio-frequency electrode disposed in the first region and a second radio-frequency electrode disposed in the second region. The focus ring has an inner peripheral edge that horizontally faces the outer peripheral edge of the substrate when the substrate is mounted on the mounting surface. In a plan view, the inner peripheral edge of the second radio-frequency electrode is located between the outer peripheral edge of the substrate and the inner peripheral edge of the focus ring.

[0007] The first high-frequency electrode and the second high-frequency electrode may be configured to be spaced apart from each other in a plan view.

[0008] The focus ring may be configured such that, in a plan view, it is divided into an annular inner region and an annular outer region located on the outer periphery of the inner region, an upper surface of the inner region is located lower than an upper surface of the outer region, a step surface located at the boundary between the inner region and the outer region is horizontally opposed to an outer peripheral end face of the substrate, and a portion of the inner region is located below the substrate when the substrate is placed on the placement surface.

[0009] An edge on an outer circumferential side of the first high-frequency electrode may be located more inward than the boundary between the first region and the second region, and an edge on an inner circumferential side of the second high-frequency electrode may be located more outward than the boundary between the first region and the second region.

[0010] The chucking electrode may include a first chucking electrode disposed in the first region and a second chucking electrode disposed in the second region.

[0011] A distance from a back surface opposite to the mounting surface to the first high-frequency electrode in a thickness direction of the electrostatic chuck plate may be greater than a distance from the back surface to the second high-frequency electrode.

[0012] A distance from an upper surface of the first region to the first high-frequency electrode in a thickness direction of the electrostatic chuck plate may be substantially equal to a distance from an upper surface of the second region to the second high-frequency electrode. [Effects of the Invention]

[0013] According to one aspect of the present invention, there is provided an electrostatic chuck device having an improved electric field strength distribution within a substrate plane. [Brief explanation of the drawings]

[0014] [Figure 1] FIG. 1 is a cross-sectional view of an electrostatic chuck device according to an embodiment. [Figure 2] FIG. 2 is an enlarged partial cross-sectional view showing the outer periphery of the electrostatic chuck device. [Figure 3] FIG. 3 is an explanatory diagram of the model used in the electromagnetic field simulation. [Figure 4] FIG. 4 is a graph showing the analysis results of the electric field strength and the electric field perpendicularity. DETAILED DESCRIPTION OF THE INVENTION

[0015] Hereinafter, embodiments of the electrostatic chuck device of the present invention will be described with reference to the drawings. In all of the drawings, the dimensions and proportions of the components may be displayed differently as appropriate to make the drawings easier to understand.

[0016] Fig. 1 is a cross-sectional view of an electrostatic chuck device according to this embodiment, and Fig. 2 is a partial cross-sectional view showing an enlarged outer periphery of the electrostatic chuck device.

[0017] The electrostatic chuck device 1 shown in FIG. 1 is placed in a vacuum chamber of a plasma processing apparatus with a mounting surface 2a on which a wafer W is placed facing upward. In this specification, the Z axis shown in FIG. 1 is a direction parallel to the vertical direction. The central axis O of the mounting surface 2a is parallel to the Z axis. In this specification, the upper side in the Z axis direction is simply referred to as the "upper side," and the lower side in the Z axis direction is simply referred to as the "lower side." Furthermore, the direction in which the central axis O of the mounting surface 2a extends may be simply referred to as the "axial direction," and the radial direction centered on the central axis O may be simply referred to as the "radial direction." The arrangement of the electrostatic chuck device 1 is an example, and other arrangements may be used.

[0018] The electrostatic chuck device 1 includes an electrostatic chuck plate 10 that attracts and supports a substrate such as a wafer W, and a metal base 11 that supports the electrostatic chuck plate 10. A focus ring 5 that surrounds a mounting surface 2a (wafer W) in a plan view is disposed on the outer periphery of the upper surface of the electrostatic chuck plate 10.

[0019] The electrostatic chuck plate 10 includes a dielectric substrate 2 having a mounting surface 2a on which a wafer W is placed, an adsorption electrode 6 and a high-frequency electrode 7 located inside the dielectric substrate 2, and a heater 9 located on the underside of the dielectric substrate 2.

[0020] The dielectric substrate 2 has a circular shape in a plan view. The dielectric substrate 2 is made of a composite sintered body that has mechanical strength and durability against corrosive gases and their plasma. As a dielectric material constituting the dielectric substrate 2, ceramics that have mechanical strength and durability against corrosive gases and their plasma are preferably used. As a ceramic constituting the dielectric substrate 2, for example, aluminum oxide sintered body, aluminum nitride sintered body, aluminum oxide-silicon carbide composite sintered body, etc. are preferably used.

[0021] The upper surface of the dielectric substrate 2 is a mounting surface 2a on which the wafer W is placed. A plurality of protrusions 21 are formed at predetermined intervals on the mounting surface 2a. Each of the plurality of protrusions 21 has a diameter smaller than the thickness of the wafer W. The plurality of protrusions 21 on the mounting surface 2a support the wafer W.

[0022] The electrostatic chuck plate 10 has a first region 10a consisting of a mounting surface 2a that supports the wafer W, and a second region 10b located radially outward of the mounting surface 2a and supporting the focus ring 5. In this embodiment, the upper surface of the second region 10b that supports the focus ring 5 is located lower than the mounting surface 2a (first region 10a) in the vertical direction in the figure. A step surface 10c consisting of an end surface facing the outer periphery is formed between the first region 10a and the second region 10b. The focus ring 5 is placed on the second region 10b. When the focus ring 5 is placed on the second region 10b, the height position (vertical position) of the upper surface of the focus ring 5 substantially coincides with the height position of the upper surface of the wafer W placed on the mounting surface 2a.

[0023] In this embodiment, the electrostatic chuck plate 10 has a step between the mounting surface 2a and the ring mounting surface 2d. This configuration makes it easier to eliminate the step between the upper surface of the wafer W and the upper surface of the focus ring 5 when a focus ring 5 thicker than the wafer W is used, thereby suppressing uneven plasma flow around the outer periphery of the wafer W. Furthermore, the step makes it difficult for the focus ring 5 to move in the planar direction. This makes it easier to maintain an appropriate positional relationship between the focus ring 5 and the wafer W.

[0024] The upper surface of the second region 10b of the electrostatic chuck plate 10 is a ring mounting surface 2d that attracts the focus ring 5. In this embodiment, the ring mounting surface 2d is provided with a gas flow path 2e, which is a groove recessed downward from the ring mounting surface 2d. The gas flow path 2e is an annular groove that circles the periphery of the mounting surface 2a. The upward opening of the gas flow path 2e is blocked by the focus ring 5 that is attracted to the ring mounting surface 2d. Note that the electrostatic chuck plate 10 may also be configured without the gas flow path 2e in the second region 10b.

[0025] Focus ring 5 is made of, for example, a material having electrical conductivity equivalent to that of wafer W placed on mounting surface 2a. Specifically, silicon, silicon carbide, quartz, aluminum oxide, or the like can be used as the material for focus ring 5. By providing focus ring 5, the electrical environment relative to the plasma at the peripheral portion of wafer W can be made roughly the same as that of wafer W. This reduces the likelihood of differences or biases in plasma processing between the center and peripheral portions of wafer W.

[0026] The chucking electrode 6 is located inside the dielectric substrate 2. The chucking electrode 6 has a first chucking electrode 61 and a second chucking electrode 62. The first chucking electrode 61 is located in the first region 10a of the electrostatic chuck plate 10. The second chucking electrode 62 is located in the second region 10b of the electrostatic chuck plate 10. The first chucking electrode 61 is located in the center of the electrostatic chuck plate 10, and the second chucking electrode 62 is located in the outer periphery of the electrostatic chuck plate 10.

[0027] The first chucking electrode 61 is located below the mounting surface 2a. The first chucking electrode 61 has, for example, a circular shape in a plan view. The first chucking electrode 61 chucks the wafer W onto the mounting surface 2a. The first chucking electrode 61 is not limited to a monopolar chucking electrode, but may be a bipolar chucking electrode consisting of two semicircular electrodes in a plan view.

[0028] The second chucking electrode 62 is located below the ring mounting surface 2d. The second chucking electrode 62 has an annular plate shape extending along the second region 10b. The second chucking electrode 62 attracts the focus ring 5 to the ring mounting surface 2d. In this embodiment, the first chucking electrode 61 attracts the wafer W and the second chucking electrode 62 attracts the focus ring 5 as separate electrodes. This allows the wafer W and the focus ring 5 to be attracted to the electrostatic chuck plate 10 with an appropriate attracting force. Both the wafer W and the focus ring 5 can be stably held.

[0029] The second attracting electrode 62 is not limited to a monopolar attracting electrode, but may be a bipolar attracting electrode consisting of two concentric annular electrodes. The focus ring 5 may be configured to be fixed using a frame, screws, or the like. In other words, the electrostatic chuck device 1 may be configured without the second attracting electrode 62.

[0030] The high-frequency electrode 7 is located inside the dielectric substrate 2. The high-frequency electrode 7 is located lower than the chucking electrode 6 in the thickness direction of the dielectric substrate 2. The high-frequency electrode 7 has a first high-frequency electrode 71 and a second high-frequency electrode 72. The first high-frequency electrode 71 is located in the first region 10a of the electrostatic chuck plate 10. The second high-frequency electrode 72 is located in the second region 10b of the electrostatic chuck plate 10. The first high-frequency electrode 71 is located at a position that substantially overlaps with the first chucking electrode 61 in a plan view. The second high-frequency electrode 72 is located at a position that substantially overlaps with the second chucking electrode 62 in a plan view.

[0031] FIG. 2 shows an enlarged view of the outer periphery of the electrostatic chuck plate 10. In FIG. 2, the shape of the focus ring 5 and its positional relationship with other components, which are shown in a simplified manner in FIG. 1, are shown in detail. On the other hand, for ease of explanation, the attraction electrode 6, the gas flow path 2e, and the like are not shown in FIG.

[0032] 2, the focus ring 5 is divided into an inner peripheral region 5a that is annular in plan view and an outer peripheral region 5b that is annular in plan view and is located on the outer periphery of the inner peripheral region 5a. An upper surface 5c of the inner peripheral region 5a is located lower than an upper surface 5d of the outer peripheral region 5b. That is, the focus ring 5 has a recess 5A that is recessed downward on the inner periphery of the upper surface of the focus ring 5.

[0033] The focus ring 5 has a step surface 5e facing the inner periphery of the focus ring 5 at the boundary between the inner periphery region 5a and the outer periphery region 5b. The step surface 5e surrounds the wafer W from the outer periphery. The step surface 5e faces the outer periphery end face Wa of the wafer W in the horizontal direction. In this embodiment, the step surface 5e also serves as the inner periphery end face of the focus ring 5 facing the inner periphery. Therefore, the focus ring 5 has an inner periphery end face that faces the outer periphery end face Wa of the wafer W in the horizontal direction.

[0034] In this embodiment, the innermost end of focus ring 5 is located very close to step surface 10c between first region 10a and second region 10b. When wafer W is placed on mounting surface 2a, it is located closer to the outer periphery of electrostatic chuck plate 10 than step surface 10c. Therefore, part of the inner periphery of focus ring 5 is located below wafer W placed on mounting surface 2a. The outer periphery of wafer W, which protrudes further outward than mounting surface 2a, is located within recess 5A of focus ring 5.

[0035] A first high-frequency electrode 71 is disposed below the mounting surface 2a. A second high-frequency electrode 72 is disposed below the ring mounting surface 2d. The first high-frequency electrode 71 and the second high-frequency electrode 72 are disposed at different vertical positions within the dielectric substrate 2. However, in the thickness direction (vertical direction) of the dielectric substrate 2, a distance L1 from the mounting surface 2a to the first high-frequency electrode 71 and a distance L2 from the ring mounting surface 2d to the second high-frequency electrode 72 are substantially equal. That is, the distances L1 and L2 are equal or close to each other. The distance L1 is preferably 0.9 to 1.1 times the distance L2. The distance L1 may be 0.95 to 0.97 times the distance L2. The distance L1 may be 1.05 to 1.03 times the distance L2.

[0036] In this embodiment, the distance L1a from the back surface 2f of the electrostatic chuck plate 10 to the first high-frequency electrode 71 is larger than the distance L2a from the back surface 2f to the second high-frequency electrode 72. This configuration makes it easier to flatten the back surface 2f of the electrostatic chuck plate 10. This makes it easier to improve the uniformity of heating by the heater 9 and the uniformity of cooling by the metal base 11. It is more preferable that the back surface 2f be a flat surface perpendicular to the central axis O of the electrostatic chuck plate 10.

[0037] In plan view, the first high-frequency electrode 71 is located closer to the inner periphery than the step surface 10c between the first region 10a and the second region 10b. That is, a part of the dielectric substrate 2 is disposed between the outer peripheral edge 71a of the first high-frequency electrode 71 and the step surface 10c. The horizontal distance L3 between the outer peripheral edge 71a of the first high-frequency electrode 71 and the step surface 10c is preferably 1 mm or more, and more preferably 1.5 mm or more. The horizontal distance L3 between the outer peripheral edge 71a of the first high-frequency electrode 71 and the step surface 10c is preferably 3 mm or less, and more preferably 2.5 mm or less.

[0038] The second high-frequency electrode 72 is located inside the second region 10b in plan view. That is, an inner peripheral edge 72a of the second high-frequency electrode 72 is located more outer peripherally than the step surface 10c between the first region 10a and the second region 10b. An outer peripheral edge 72b of the second high-frequency electrode 72 is located more inner peripherally than the outer peripheral edge of the second region 10b. The outer peripheral edge 72b of the second high-frequency electrode 72 is preferably located 1 mm or more inward from the outer peripheral edge of the dielectric substrate 2, and more preferably 1.5 mm or more inward.

[0039] In this embodiment, the first high-frequency electrode 71 is located closer to the inner periphery than the boundary (step surface 10c) between the first region 10a and the second region 10b. On the other hand, the second high-frequency electrode 72 is located closer to the outer periphery than the boundary (step surface 10c) between the first region 10a and the second region 10b. Therefore, the first high-frequency electrode 71 and the second high-frequency electrode 72 are spaced apart from each other in a plan view. If the first high-frequency electrode 71 and the second high-frequency electrode 72 are spaced apart due to structural constraints of the electrostatic chuck plate 10, a planar region where no high-frequency electrode is present will be formed around the outer periphery of the wafer W. In such a configuration, non-uniformity in the electric field strength on the wafer W is likely to occur. However, by employing the configuration of this embodiment, which will be described later, the uniformity of the electric field strength can be improved.

[0040] In this embodiment, the inner peripheral edge 72a of the second high-frequency electrode 72 is located within a section R1 between the outer peripheral end surface Wa of the wafer W and the stepped surface 5e of the focus ring 5 (the inner peripheral end surface of the focus ring 5 that faces the outer peripheral end surface Wa in the horizontal direction) in a plan view. More specifically, the inner peripheral boundary of the section R1 is the outer peripheral end surface Wa of the wafer W. The outer peripheral boundary of the section R1 is the lower end 5f of the stepped surface 5e of the focus ring 5. By having the inner peripheral edge 72a of the second high-frequency electrode 72 located within the section R1, the vertical electric field intensity distribution on the wafer W can be made closer to a more uniform distribution.

[0041] The inventors performed an electromagnetic field simulation to determine the position of the inner peripheral edge 72a of the second high-frequency electrode 72 and found a position where the electric field intensity distribution could be improved. FIG. 3 is an explanatory diagram showing a model of an electrostatic chuck device used in the electromagnetic field simulation. As shown in FIG. 3, the model used for analysis was configured such that a high-frequency power supply terminal for a wafer, a high-frequency power supply terminal for a focus ring, and a quartz protective member were arranged in the electrostatic chuck device 1 shown in FIGS. 1 and 2. The surrounding environment was such that high-density plasma was distributed above the electrostatic chuck device, low-density plasma was distributed on the sides, and a vacuum was formed below the metal base.

[0042] The wafer diameter was set to φ300 mm. The positions of the various parts shown in Figure 2 are as follows: Radial position of the outer peripheral edge Wa of the wafer W: 150 mm Radial position of the lower end 5f of the step surface 5e: 151 mm Radial position of the upper end 5h of the step surface 5e: 152 mm Radial position of step surface 10c: 148mm Radial position of the edge 71a of the first high-frequency electrode 71: 146 mm Thickness of the first high-frequency electrode 71 and the second high-frequency electrode 72: 50 μm

[0043] (Simulation conditions) Analysis software: High frequency analysis software ANSYS HFSS (manufactured by ANSYS) Analysis frequency: 500kHz (adjust the input value of high frequency power (W) as appropriate) Model conditions: Metal base and each power supply terminal are metal, no finite elements. The relative permittivity, electrical conductivity, and dielectric tangent of each material are listed in Table 1.

[0044] [Table 1]

[0045] FIG. 4 is a graph showing the electric field strength distribution and the electric field perpendicularity distribution on the wafer obtained by electromagnetic field simulation. "On-wafer electric field strength uniformity" was evaluated by normalizing the vertical electric field strength at each position on the wafer with the vertical electric field strength at the center of the wafer, and calculating the area ratio where the obtained electric field strength ratio was 100±0.2%. The "verticality of the electric field on the wafer" was evaluated as the area ratio where the inclination of the electric field on the wafer was ±0.1° with respect to the vertical direction. For both "uniformity of electric field strength on wafer" and "verticality of electric field on wafer," the closer to 100%, the higher the uniformity of the electric field on the wafer.

[0046] 4, when the radial position of the inner peripheral edge 72a of the second high-frequency electrode 72 is changed, the electric field strength distribution and the electric field perpendicularity distribution on the wafer W change. The "electric field strength uniformity on the wafer" has a peak at a radius of 151 mm, and is highly uniform in the radius range of 148 mm to 152 mm. The "electric field perpendicularity on the wafer" has a peak at a radius of approximately 150 mm, and the uniformity decreases with increasing distance from the peak position.

[0047] The position at a radius of 151 mm where the "electric field strength uniformity on the wafer" is maximized is the radial position of the lower end 5f of the stepped surface 5e of the focus ring 5. Furthermore, the position at a radius of 150 mm where the "electric field perpendicularity on the wafer" is maximized is the radial position of the outer peripheral edge face Wa of the wafer W. Therefore, by disposing the inner peripheral edge 72a of the second high-frequency electrode 72 between the stepped surface 5e of the focus ring 5 (the inner peripheral edge face facing the wafer W) and the outer peripheral edge face Wa of the wafer W, high uniformity can be obtained in both the electric field strength uniformity on the wafer W and the electric field perpendicularity on the wafer W.

[0048] 1, the heater 9 is, for example, a thin-film heater having a substantially circular shape in a plan view. The heater 9 is bonded to the lower surface of the dielectric substrate 2. The heater 9 is located in a region overlapping with the mounting surface 2a in a plan view. That is, the heater 9 is disposed at a position overlapping with the wafer W placed on the mounting surface 2a in a plan view.

[0049] The configuration and arrangement of the heater 9 shown in FIG. 1 are one example, and various modifications are possible. The heater 9 may be provided inside the dielectric substrate 2. The heater 9 may be bonded to the metal base 11. The heater 9 may be provided inside the metal base 11. The heater 9 may be made of ceramics or metal wire. The electrostatic chuck device 1 may also be configured without the heater 9.

[0050] The metal base 11 is made of a thick, disk-shaped metal member. The metal base 11 of this embodiment is a water-cooled base having a flow path 11a therein for circulating a coolant such as water. The metal base 11 may not necessarily have the flow path 11a. There are no particular limitations on the material that can be used to form the metal base 11, as long as it is a metal with excellent thermal conductivity, electrical conductivity, and workability, or a composite material containing such a metal. For example, aluminum, an aluminum alloy, copper, a copper alloy, stainless steel, etc. are preferably used.

[0051] In the electrostatic chuck device 1, the lower surface of the electrostatic chuck plate 10 and the upper surface of the metal base 11 are bonded together via an adhesive layer 12. The adhesive layer 12 seals the heater 9 therein. The adhesive layer 12 is made of, for example, a heat-resistant resin such as a polyimide resin, a silicone resin, or an epoxy resin, or an insulating sheet- or film-shaped adhesive resin.

[0052] According to the electrostatic chuck device 1 having the above-described configuration, the radial position of the second high-frequency electrode 72 located below the focus ring 5 is appropriately set, whereby the uniformity of the electric field intensity on the wafer W and the verticality of the electric field can be improved.

[0053] In the electrostatic chuck plate 10 of the present embodiment, the first region 10a and the second region 10b may be formed of different members. That is, the dielectric substrate 2 may be divided at the position of the step surface 10c into a disk-shaped dielectric substrate forming the first region 10a and an annular dielectric substrate forming the second region 10b. [Explanation of symbols]

[0054] REFERENCE SIGNS LIST 1...electrostatic chuck device, 2...dielectric substrate, 2a...mounting surface, 2d...ring mounting surface, 2e...gas flow path, 2f...rear surface, 5...focus ring, 5a...inner peripheral region, 5b...outer peripheral region, 5c, 5d...upper surface, 5e, 10c...step surface, 5f...lower end, 5h...upper end, 5A...recess, 6...chucking electrode, 7...high-frequency electrode, 9...heater, 10...electrostatic chuck plate, 10a...first region, 10b...second region, 11...metal base, 11a...flow path, 12...adhesive layer, 21...projection, 61...first chucking electrode, 62...second chucking electrode, 71...first high-frequency electrode, 71a, 72a, 72b...edge, 72...second high-frequency electrode, L1, L2, L1a, L2a...distance, L3...interval, O...center axis, R1...section, W...wafer, Wa...periphery edge

Claims

1. an electrostatic chuck plate including a dielectric substrate having a mounting surface on which a substrate is placed, an attraction electrode located inside the dielectric substrate, and a high-frequency electrode for applying a high-frequency voltage to the substrate; a metal base supporting the electrostatic chuck plate from a back surface side opposite to the mounting surface; a focus ring disposed on an outer periphery of the electrostatic chuck plate and surrounding the mounting surface; An electrostatic chuck device comprising: the electrostatic chuck plate is partitioned, in a plan view, into a first region that supports a substrate and a second region that surrounds the first region and has a ring mounting surface on which the focus ring is mounted, the high-frequency electrode includes a first high-frequency electrode disposed in the first region and a second high-frequency electrode disposed in the second region; the focus ring has an inner peripheral end surface that faces horizontally an outer peripheral end surface of the substrate when the substrate is placed on the placement surface, and is partitioned in a plan view into an annular inner peripheral region and an annular outer peripheral region located outer circumferentially of the inner peripheral region, and an upper surface of the inner peripheral region is located lower than an upper surface of the outer peripheral region, a step surface located at the boundary between the inner circumferential region and the outer circumferential region is the inner circumferential end surface, a mounting surface that faces an outer peripheral end surface of the substrate in a horizontal direction, and a portion of the inner peripheral region is located below the substrate when the substrate is placed on the mounting surface; an inner peripheral edge of the second high-frequency electrode is located between an outer peripheral end surface of the substrate and the inner peripheral end surface of the focus ring in a plan view; Electrostatic chuck device.

2. the first high-frequency electrode and the second high-frequency electrode are disposed apart from each other in a plan view.

2. The electrostatic chuck device according to claim 1.

3. an outer peripheral edge of the first high-frequency electrode is located on the inner peripheral side of a boundary between the first region and the second region, an inner peripheral edge of the second high-frequency electrode is located on the outer peripheral side of the boundary between the first region and the second region; 3. The electrostatic chuck device according to claim 1 or 2.

4. The chucking electrode includes a first chucking electrode disposed in the first region and a second chucking electrode disposed in the second region. The electrostatic chuck device according to any one of claims 1 to 3.

5. a distance from a back surface opposite to the mounting surface to the first high-frequency electrode in a thickness direction of the electrostatic chuck plate is greater than a distance from the back surface to the second high-frequency electrode; The electrostatic chuck device according to claim 1 .

6. a distance from an upper surface of the first region to the first high-frequency electrode in a thickness direction of the electrostatic chuck plate is substantially equal to a distance from an upper surface of the second region to the second high-frequency electrode; 6. The electrostatic chuck device according to claim 5.

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