Electrostatic chuck device and rotating body

Abstract

This electrostatic chuck device includes: a rotating body that has an electrostatic chuck member and a rotating stage that holds the electrostatic chuck member, and is rotatable in the circumferential direction about the central axis passing through the rotating body; a base positioned in the central axis direction; and a rotation mechanism that rotates the rotating body in the circumferential direction about the central axis. The electrostatic chuck member has a dielectric substrate, an internal electrode embedded in the dielectric substrate, and a terminal connected to the internal electrode. The base has a conductive part that is electrically connected to the internal electrode. The internal electrode has a first electrode and a second electrode. The terminal has one or more first terminals connected to the first electrode and one or more second terminals connected to the second electrode. The conductive part has a first conductive part connected to the first terminal via a first conductive liquid and a second conductive part connected to the second terminal via a second conductive liquid. The terminals are arranged rotationally symmetrically with respect to the central axis.

Description

Electrostatic chuck device and rotating body

[0001] The present invention relates to an electrostatic chuck device and a rotating body. This application claims priority under Japanese Patent Application No. 2024-196415, filed on November 11, 2024, the contents of which are incorporated herein by reference.

[0002] Conventionally, electrostatic chuck devices for holding plate-shaped samples such as semiconductor wafers are known. Electrostatic chuck devices are used in semiconductor manufacturing processes to hold plate-shaped samples during plasma treatment or thin film deposition on them. Such electrostatic chuck devices are known that can rotate a plate-shaped sample (a disc-shaped sample) in the circumferential direction while holding it (see, for example, Patent Document 1).

[0003] Special Publication No. 2021-506136

[0004] Due to recent advancements in semiconductor manufacturing processes, the applications of electrostatic chuck devices extend beyond the processes mentioned above. Considering their potential use in various processes, the electrostatic chuck device described in Patent Document 1 still has room for improvement.

[0005] The present invention has been made in view of these circumstances, and aims to provide a novel electrostatic chuck device that enables the rotation of a held plate-shaped sample in the circumferential direction. It also aims to provide a novel rotating body for holding a plate-shaped sample and for use in such an electrostatic chuck device.

[0006] To solve the above problems, one aspect of the present invention includes the following aspects.

[0007] [1] An electrostatic chuck device comprising: an electrostatic chuck member; a rotating stage for holding the electrostatic chuck member; a rotating body rotatable in the circumferential direction of a central axis through which it passes; a base positioned in the axial direction of the central axis; and a rotating mechanism for rotating the rotating body in the circumferential direction of the central axis, wherein the electrostatic chuck member comprises: a dielectric substrate; an internal electrode enclosed in the dielectric substrate; and terminals connected to the internal electrode; the base has a conductive portion that is in electrical contact with the internal electrode; the internal electrode comprises a first electrode and a second electrode; the terminal comprises: one or more first terminals connected to the first electrode; and one or more second terminals connected to the second electrode; the conductive portion comprises: a first conductive portion connected to the first terminal via a first conductive liquid; and a second conductive portion connected to the second terminal via a second conductive liquid; and the terminals are arranged rotationally symmetrically with respect to the central axis.

[0008] [2] The electrostatic chuck device according to [1], wherein the first electrode is provided so as to overlap with the central axis in a plan view, the second electrode is provided radially outward from the central axis relative to the first electrode, one first terminal is provided so as to overlap with the central axis, and a plurality of second terminals are arranged rotationally symmetric with respect to the central axis.

[0009] [3] The electrostatic chuck device according to [1] or [2], wherein the first electrode is a cylindrical member that penetrates the rotating stage and extends in the direction of the central axis, and the first conductive portion is a first fluid bearing that rotatably holds the first terminal via the first conductive liquid.

[0010] [4] The electrostatic chuck device according to any one of [1] to [3], wherein the second conductive portion has an annular first protrusion provided concentrically with the central axis and a supply device that supplies the second conductive liquid to at least the top of the first protrusion, and the second fluid bearing that rotatably supports the rotating stage via the second conductive liquid supplied to the top.

[0011] [5] The electrostatic chuck device according to [4], wherein the rotating stage is provided concentrically with the central axis and has a second protrusion that faces the inner or outer surface of the first protrusion with a gap between them, and the supply device supplies the second conductive liquid into the gap between the first protrusion and the second protrusion.

[0012] [6] The electrostatic chuck device according to any one of [1] to [5], wherein the rotating mechanism comprises a magnet provided on the rotating body and arranged in the circumferential direction of the central axis, and a plurality of coils provided on the base, facing the magnet with a gap between them and arranged in the circumferential direction of the central axis.

[0013] [7] The electrostatic chuck apparatus according to any one of items [1] to [6], wherein either or both of the first conductive liquid and the second conductive liquid are ionic liquids.

[0014] [8] A rotating body comprising an electrostatic chuck member and a rotating stage that holds the electrostatic chuck member and is rotatable around a central axis through which it passes, wherein the electrostatic chuck member has a dielectric substrate, an internal electrode enclosed in the dielectric substrate, and terminals connected to the internal electrode, the internal electrode having a first electrode and a second electrode, and the terminals having one or more first terminals connected to the first electrode and one or more second terminals connected to the second electrode, and the terminals being a rotating body arranged rotationally symmetrically with respect to the central axis.

[0015] [9] The rotating body according to [8], wherein the first electrode is provided so as to overlap with the central axis in a plan view, the second electrode is provided radially outward from the central axis relative to the first electrode, one first terminal is provided so as to overlap with the central axis, and a plurality of second terminals are arranged rotationally symmetric with respect to the central axis.

[0016] According to the present invention, a novel electrostatic chuck device is provided that enables the circumferential rotation of a held plate-shaped sample. Furthermore, a novel rotating body is provided for use in such an electrostatic chuck device to hold a plate-shaped sample.

[0017] Figure 1 is a schematic perspective view showing the electrostatic chuck device 1. Figure 2 is a cross-sectional view of the rotating body 10 along line segment A-A in Figure 1. Figure 3 is a cross-sectional view of the base 20 along line segment A-A in Figure 1. Figure 4 is a cross-sectional view of the electrostatic chuck device 1 along line segment A-A in Figure 1. Figure 5 is a perspective cross-sectional view of the electrostatic chuck device 1.

[0018] The electrostatic chuck device and rotating body according to this embodiment will be described below with reference to Figures 1 to 5. Note that in all the following drawings, the dimensions and proportions of each component have been appropriately altered for clarity.

[0019] In the following explanation, the z-axis is defined vertically, with the upward direction being the +z direction and the downward direction being the -z direction.

[0020] 《Electrostatic Chuck Device, Rotating Body》 Figure 1 is a schematic perspective view showing an electrostatic chuck device 1. As shown in Figure 1, the electrostatic chuck device 1 of this embodiment has a rotating body 10, a base 20, and a rotation mechanism (described later). The rotating body 10 corresponds to the "rotating body" in the present invention.

[0021] [Rotating body] The rotating body 10 comprises an electrostatic chuck member 11 and a rotating stage 12. The rotating body 10 is circular in plan view and is rotatable in the circumferential direction of a central axis C that penetrates the rotating mechanism itself.

[0022] <Electrostatic Chuck Member> The electrostatic chuck member 11 includes a dielectric substrate 111, an internal electrode 112 enclosed within the dielectric substrate 111, and terminals 113 and 114 connected to the internal electrode 112. The upper surface of the electrostatic chuck member 11 is provided with a mounting surface 11s for adsorbing plate-shaped members such as wafers. The dielectric substrate 111 and the rotating stage 12 are bonded together with an insulating adhesive (not shown).

[0023] (Dielectric Substrate) The dielectric substrate 111 is made of ceramics that have sufficient mechanical strength and durability against the use environment. For example, when the use environment of the electrostatic chuck device 1 is a plasma environment, the dielectric substrate 111 is required to have durability against the corrosive gas that becomes a plasma source and the plasma generated from the corrosive gas. Therefore, ceramics having durability against the above plasma are used as the material.

[0024] The ceramics constituting the dielectric substrate 111 contain aluminum oxide (Al ２ O ３ ) as a main component. "Main component" means occupying 50% or more of the total volume. For example, aluminum oxide (Al ２ O ３ ) sintered body, aluminum oxide (Al ２ O ３ ) - silicon carbide (SiC) composite sintered body, etc. are preferably used. Also, aluminum nitride (AlN), silicon nitride (Si ３ N ４ ), yttrium (III) oxide (Y ２ O ３ ), yttrium aluminum garnet (YAG), and SmAlO ３ etc. may also be used. In particular, from the viewpoints of dielectric properties at high temperatures, high corrosion resistance, plasma resistance, and heat resistance, the material constituting the dielectric substrate 111 may be an Al ２ O ３ - SiC composite sintered body. Note that known insulating materials (ceramics) can also be used as the material of the dielectric substrate 111.

[0025] The dielectric substrate 111 is circular plate-shaped in plan view. In this specification, "plan view" refers to the view seen from the thickness direction of the electrostatic chuck member 11.

[0026] (Internal Electrode) The internal electrode 112 has a first electrode 112A and a second electrode 112B. The first electrode 112A of the electrostatic chuck member 11 of this embodiment is circular in plan view and coincides with the central axis C. The second electrode 112B is annular in plan view and is positioned radially outward from the central axis C relative to the first electrode 112A. The dielectric substrate 111, the first electrode 112A and the second electrode 112B are concentric, and the centers of the first electrode 112A and the second electrode 112B coincide with the central axis C in plan view.

[0027] The first electrode 112A is subjected to a high potential via the first terminal 113, described later, and is used as an electrostatic adsorption electrode. The second electrode 112B is connected to the GND potential via the second terminal 114, described later, and is used as a GND electrode.

[0028] The internal electrode 112 may be composed solely of a conductive material, or it may be composed of a composite material (ceramics) of an insulating material and a conductive material, as long as it is conductive.

[0029] The insulating material contained in the internal electrode 112 is not particularly limited, but for example, aluminum oxide (Al ２ O ３ ), aluminum nitride (AlN), silicon dioxide (SiO ２ ), silicon nitride (Si ３ N ４ ), yttrium(III) oxide (Y ２ O ３ ), yttrium aluminum garnet (YAG) and SmAlO ３ It may be at least one selected from the group consisting of the following:

[0030] The conductive material contained in the internal electrode 112 is molybdenum carbide (Mo ２ C), molybdenum (Mo), tungsten carbide (WC), tungsten (W), tantalum carbide (TaC), tantalum (Ta), niobium carbide (NbC), niobium (Nb), ruthenium (Ru), silicon carbide (SiC), carbon black, carbon nanotubes, and carbon nanofibers may be selected from the group.

[0031] The internal electrode 112 may be a composite of an insulating material and a conductive material, and may contain the same material as the insulating material that is the main component of the dielectric substrate 111. In this case, in the sintering operation during the manufacture of the electrostatic chuck member 11, the bonding strength of the boundary portion between the dielectric substrate 111 and the internal electrode 112 can be increased.

[0032] When the internal electrode 112 is a composite of an insulating material and a conductive material, the content rate (volume ratio) of the conductive material in the internal electrode 112 is appropriately adjusted according to the application. The content rate may be 20% by volume or more and 80% by volume or less, may be 23% by volume or more and 60% by volume or less, or may be 25% by volume or more and 50% by volume or less. The upper limit value and the lower limit value of the content rate can be arbitrarily combined.

[0033] By setting the content rate of the conductive material in the internal electrode 112 to 20% by volume or more, conductivity suitable for an electrode can be imparted to the internal electrode 112. Further, by setting the content rate to 80% by volume or less, the thermal expansion difference between the internal electrode 112 and the dielectric substrate 111 is reduced, and the dielectric substrate 111 and the internal electrode 112 can be satisfactorily joined during the manufacture of the electrostatic chuck member 11.

[0034] The thickness of the electrostatic chuck member 11 can be appropriately set according to the usage of the electrostatic chuck device 1. When the electrostatic chuck device 1 is used in a plasma process, the thickness of the electrostatic chuck member 11 may be 0.5 mm or more and 5 mm or less. When the thickness of the electrostatic chuck member 11 is 0.5 mm or more, the withstand voltage of the electrostatic chuck member 11 becomes high. Further, when the thickness of the electrostatic chuck member 11 is 5 mm or less, the heat capacity of the electrostatic chuck member 11 becomes small. Therefore, it becomes easier to keep the temperature of the plate-like sample, which is the object to be processed, uniform during the plasma treatment.

[0035] (Terminal) The terminal has a first terminal 113 connected to the first electrode 112A and a second terminal 114 connected to the second electrode 112B. As shown in FIG. 1, the electrostatic chuck member 11 has one first terminal 113 connected to the first electrode 112A and three second terminals 114A, 114B, and 114C connected to the second electrode 112B.

[0036] The first terminal 113 is a columnar member that penetrates the rotary stage 12 and extends in the central axis direction. The first terminal 113 is provided so as to overlap the central axis C in a plan view.

[0037] Also, the three second terminals 114A, 114B, and 114C are arranged at equal intervals in the circumferential direction of the central axis C. Specifically, the three second terminals 114A, 114B, and 114C are provided on the same virtual circle whose center overlaps the central axis C, and the arc arc1 between the second terminals 114A and 114B, the arc arc2 between the second terminals 114B and 114C, and the arc arc3 between the second terminals 114A and 114C are of the same length. The central angle of each of the arcs arc1, arc2, and arc3 is 120°.

[0038] Therefore, the first terminal 113 and the second terminal 114 are arranged rotationally symmetrically with respect to the central axis C.

[0039] Note that the terminals being "rotationally symmetric with respect to the central axis C" means that in a plan view, when the first terminal 113 and the second terminal 114 are rotated by (360 / n)° (where n is an integer of 2 or more) around the central axis C, the arrangement of each terminal before rotation and the arrangement of each terminal after rotation overlap. In the electrostatic chuck device 1 shown in FIG. 1, the first terminal 113 that overlaps the central axis C always overlaps its own arrangement before and after rotation. The second terminal 114 overlaps its own arrangement before and after rotation every time it is rotated by 120° (n = 3) (three-fold symmetry). Therefore, it can be said that the first terminal 113 and the second terminal 114 of the electrostatic chuck device 1 are rotationally symmetric with respect to the central axis C.

[0040] In addition to the configuration shown in FIG. 1, the second terminal can also adopt an annular configuration having a center that overlaps the central axis C in a plan view. Such a second terminal always overlaps its own arrangement before and after rotation, and thus can be said to be rotationally symmetric with respect to the central axis C.

[0041] FIG. 2 is a cross-sectional view of the rotating body 10 taken along the line segment A - A in FIG. 1 as viewed in the arrow direction. As shown in FIG. 2, the first terminal 113 is composed of a terminal 115 and a shaft electrode 116. The terminal 115 and the shaft electrode 116 each exhibit a columnar shape, for example.

[0042] The terminal 115 is embedded in the through-hole 111a of the dielectric substrate 111.

[0043] The shaft electrode 116 has a cylindrical main shaft 116a and a cylindrical protrusion 116b that is smaller in diameter than the main shaft 116a and has the same diameter as the terminal 115. The shaft electrode 116 may be manufactured by integrating the main shaft 116a and the protrusion 116b as separate parts, or it may be a single component in which the main shaft 116a and the protrusion 116b are integrally manufactured from the same source by machining or the like.

[0044] The shaft electrode 116 is connected to the lower end (lower surface, -z side end) of the terminal 115 at the upper end (upper surface, +z side end) of the protrusion 116b. The lower end of the terminal 115 is, for example, at the same height as the lower surface 111x of the dielectric substrate 111 and is bonded to the shaft electrode 116 using a conductive adhesive.

[0045] An insulating member 117 is provided above the shaft electrode 116, surrounding the shaft electrode 116. The protrusion 116b of the shaft electrode 116 is inserted into the through hole 117a of the insulating member 117.

[0046] The insulating member 117 can be made from various insulating materials used as insulating materials in the present art. Furthermore, the insulating member 117 may also have chemical resistance. If the insulating member 117 has chemical resistance, the number of processes to which the electrostatic chuck device 1 can be applied increases compared to when the insulating member 117 does not have chemical resistance.

[0047] For example, resin materials such as fluororesin, polycarbonate, epoxy resin, polystyrene, and polyetheretherketone resin (PEEK) can be used as the material for the insulating member 117.

[0048] Furthermore, the second terminal 114 is composed of terminals 118 and 119. Terminals 118 and 119 are, for example, both cylindrical in shape. Terminal 118 is embedded in a through hole 111b of the dielectric substrate 111.

[0049] Terminal 119 is connected at its upper end (upper surface, +z side) to the lower end (lower surface, -z side) of terminal 118. The lower end of terminal 118 is, for example, at the same height as the lower surface 111x of the dielectric substrate 111 and is bonded to terminal 119 using a conductive adhesive.

[0050] Terminals 113 and 114 only need to be conductive and may be formed from known metal materials used for terminals, or they may be composite sintered bodies (ceramics) of insulating and conductive materials. Examples of metallic materials include metals such as aluminum, molybdenum, titanium, nickel, copper, and niobium, and alloys thereof. As for the composite sintered body of insulating and conductive materials, the same insulating and conductive materials as those used for the internal electrode 112 can be used. Terminals 113 and 114 may be made of lightweight materials so that less power is required to rotate them when rotating the rotating body 10.

[0051] Terminals 115 and 118 may be composite sintered bodies (ceramics) of insulating and conductive materials, and the insulating material contained in terminals 115 and 118 may be the same material as the main component of the dielectric substrate 111 or the insulating material of the internal electrode 112 (for example, aluminum oxide). If the main components of the dielectric substrate 111 and terminals 115 and 118 are the same, the bonding strength at the boundary between the dielectric substrate 111 and terminals 115 and 118 can be increased during sintering when manufacturing the electrostatic chuck member 11. Also, if the main components of the internal electrode 112 and terminals 115 and 118 are the same, the bonding strength at the boundary between the internal electrode 112 and terminals 115 and 118 can be increased during sintering.

[0052] From the above viewpoint, the insulating material contained in the dielectric substrate 111, the internal electrode 112, the terminal 115, and the terminal 118 may be the same material.

[0053] The content (volume ratio) of conductive material in terminals 115 and 118 is adjusted as appropriate. The content of conductive material in terminals 115 and 118 may be 20% to 80% by volume, 23% to 60% by volume, or 25% to 50% by volume. The upper and lower limits of this content can be combined arbitrarily.

[0054] By setting the conductive material content in terminals 115 and 118 to 20 volume percent or more, the terminals 115 and 118 can be given conductivity suitable for use as electrode terminals. Furthermore, by setting the content to 80 volume percent or less, the difference in thermal expansion with the dielectric substrate 111 and the internal electrode 112 is reduced, allowing for good bonding to the dielectric substrate 111 and the internal electrode 112 during the manufacturing of the electrostatic chuck member 11.

[0055] If terminals 115 and 118 are composite sintered bodies of insulating and conductive materials, they can also be joined by inserting them into through holes 111a and 111b provided in the dielectric substrate 111 as composite sintered bodies and then pressurizing and sintering them.

[0056] The terminal 119 is preferably made of a metal material such as aluminum, titanium, or molybdenum.

[0057] At terminal 113, the material of terminal 115 and the material of shaft electrode 116 may be the same or different. Also, at terminal 114, the material of terminal 118 and the material of terminal 119 may be the same or different.

[0058] Although terminal 119 is embedded in the rotating stage 12, which will be described later, the material of terminal 119 and the material of the rotating stage 12 may be the same. In that case, terminal 119 can be omitted, and its function can be ensured by the rotating stage 12.

[0059] [Rotating Stage] The rotating stage 12 is a member that holds the electrostatic chuck member 11 and rotates in the circumferential direction about the central axis C.

[0060] In the rotating body 10, the center of the electrostatic chuck member 11, which is circular in plan view, and the center of the rotating stage 12 are concentric. The concentricity of the centers of the electrostatic chuck member 11 and the rotating stage 12 can be confirmed by measuring the degree of concentricity using the method described below. A smaller value for concentricity indicates that the distance between the centers is closer.

[0061] (Measurement of concentricity) Using a three-dimensional measuring machine (manufactured by Tokyo Seimitsu Co., Ltd., RVA800A), the positions of three or more points on the outer diameter of the electrostatic chuck member 11, for example, eight points, are measured, and the center position C1 of the electrostatic chuck member 11 is determined from the measurement results. Similarly, the center position C2 of the rotating stage 12 is determined in the same way. The distance between the center position C1 and the center position C2 in a plan view is determined as the concentricity.

[0062] In the rotating body 10, a small degree of concentricity is preferable. The degree of concentricity may be, for example, 0.1 mm or less, or 0.05 mm or less. A rotating body 10 with a small degree of concentricity can be rotated stably.

[0063] The rotating stage 12 has a stage body 120 having a support surface 12s for supporting the electrostatic chuck member 11, and annular protrusions 121, 123, 125, and 129 projecting downward from the lower surface of the stage body 120. The rotating stage 12 has a cylindrical shape with the upper part of the protrusions 129 closed by the stage body 120 and the lower part open.

[0064] The protruding portion 129 is located on the outermost periphery of the stage body 120. Furthermore, radially inward from the protruding portion 129, protruding portions 125, 121, and 123 are provided in order from the side of the protruding portion 129. The protruding portions 121, 123, 125, and 129 are concentric circles whose centers coincide with the central axis C.

[0065] The protruding portion 125 has an inclined surface 125a facing the inner circumference.

[0066] The recess 122, surrounded by the protruding ridge 123 located at the innermost circumference, is provided with a through hole 12a that penetrates the rotating stage 12 (stage body 120) and a through hole 12b that communicates with the through hole 12a. The through hole 12b has a larger diameter than the through hole 12a and is located below the through hole 12a. The centers of the through holes 12a and 12b coincide with the central axis C.

[0067] An annular insulating member 117 having a side shape complementary to the through holes 12a and 12b is inserted into the through holes 12a and 12b. As a result, the first terminal 113 penetrates the rotating stage 12.

[0068] A recess 124 is formed in the area enclosed by the protruding portion 123, the protruding portion 121, and the stage body 120. A magnet 31, which constitutes part of the rotation mechanism, and a rotor core 32 are provided on the inner surface 121x of the protruding portion 121 facing the recess 124. Further details will be described later.

[0069] A recess 126 is formed in the area enclosed by the protruding portion 121, the protruding portion 125, and the stage body 120. The recess 126 is provided with a through hole 12c that penetrates the rotating stage 12 (stage body 120). The terminal 119 that constitutes the second terminal 114 described above is inserted into the through hole 12c. The lower end (bottom surface, lower end of the second terminal 114) of the terminal 119 is at the same height as the inner surface of the recess 126.

[0070] A recess 128 is formed in the area enclosed by the protruding portion 125, the protruding portion 129, and the stage body 120.

[0071] The rotating stage 12 can be manufactured by CNC machining. The material of the rotating stage 12 may be conductive, have a low specific gravity, and be chemical resistant. The material of the rotating stage 12 may be a light metal such as aluminum, or stainless steel. The surface of the rotating stage 12 may be coated with a corrosion-resistant film as needed.

[0072] [Base] Figure 3 is a cross-sectional view of the base 20 along the line segment A-A in Figure 1. The base 20 is a component located on the -z side of the central axis C of the rotating body 10.

[0073] The base 20 comprises a base body 21, an insulating member 22, and a bearing member 23.

[0074] The base body 21 has a through hole 21a that penetrates the base body 21 and a through hole 21b that communicates with the through hole 21a. The through hole 21b has a larger diameter than the through hole 21a and is located below the through hole 21a. The centers of the through holes 21a and 21b coincide with the central axis C.

[0075] The insulating member 22 has a side shape complementary to the through holes 21a and 21b, and has a recess 221 on its inside. For example, the same material as the insulating member 117 described above can be used for the insulating member 22. An annular electrode 222 is arranged in the recess 221.

[0076] The bearing member 23 is a cylindrical member located above the insulating member 22 and connected to the insulating member 22. The inner wall 23a of the bearing member 23 and the recess 221 of the insulating member 22 are in liquid-tight communication. The bearing member 23 can be formed using, for example, the same material as the insulating member 22.

[0077] The insulating member 22 and the bearing member 23 may be formed integrally.

[0078] (Base Body) The base body 21 is formed using a conductive material. The material of the base body 21 may be conductive and chemically resistant. The material of the base body 21 may be, for example, metal. Specifically, the metal may be stainless steel or aluminum. The surface of the base body 21 may be coated with a corrosion-resistant film as needed.

[0079] The base body 21 has a base portion 210 and annular protrusions 211, 213, 215, and 217 that project upward from the upper surface of the base portion 210. The protrusions 211, 213, 215, and 217 are concentric circles whose centers coincide with the central axis C.

[0080] The protruding portion 217 is located on the outermost periphery of the multiple protruding portions. The protruding portion 217 protrudes the most towards the +z side among the protruding portions 211, 213, 215, and 217. The upper end (upper surface, +z side end) of the protruding portion 217 is located above the lower end (lower surface, -z side end) of the protruding portion 125 of the rotating stage 12.

[0081] The portion of the base 210 located radially outward from the protruding ridge 217 is a flange 219 that protrudes radially outward.

[0082] The protruding portion 211 adjacent to the protruding portion 217 has a plurality of supply ports 211A for supplying an ionic liquid (conductive liquid), which will be described later. Each supply port 211A has a through hole 211a that penetrates the protruding portion 211 in the z direction and reaches the top portion 211x, and a through hole 211b that extends from the through hole 211a to the inner surface 211y of the protruding portion 211.

[0083] A recess 211c is provided at the position where the through hole 211a of the top portion 211x opens. A recess 211d is provided at the position where the through hole 211b of the inner surface 211y opens.

[0084] The protruding portion 213 is provided on the radially inner circumference side relative to the protruding portion 211. The protruding portion 213 supports a plurality of coils 33 that constitute part of the rotation mechanism. More details will be described later.

[0085] The protruding portion 215 is provided between the protruding portion 211 and the protruding portion 213.

[0086] An annular recess 212 is formed in the area surrounded by the bearing member 23, the coil 33, the insulating member 22, and the protruding portion 213.

[0087] Similarly, an annular recess 214 is formed in the area enclosed by the protruding portion 213, the protruding portion 215, and the base portion 210. The coil 33 overlaps the recess 214 from above. A through hole (not shown) may be provided in the recess 214 to allow the wire wound around the coil 33 to be brought out to the outside of the device. Such a through hole connects the internal space and the external space of the electrostatic chuck device 1. This makes it possible to match the pressure of the operating environment in which the electrostatic chuck device 1 is placed with the pressure inside the electrostatic chuck device 1.

[0088] An annular recess 216 is formed in the area enclosed by the protruding portion 215, the protruding portion 211, and the base portion 210. The recess 216 is provided with a through hole 216a that penetrates the base body 21 (base portion 210). The base body 21 may have multiple through holes 216a. The function of the through holes 216a will be described later.

[0089] An annular recess 218 is formed in the area enclosed by the protruding ridge 211, the protruding ridge 217, and the base 210. The recess 218 is provided with a through hole 218a that penetrates the base body 21 (base 210). The base body 21 may have multiple through holes 218a. The function of the through holes 218a will be described later.

[0090] Furthermore, the base 20 has a conductive portion that is in contact with the internal electrode 112 of the rotating body 10. More details will be described later.

[0091] [Electrostatic Chuck Device] Figure 4 is a cross-sectional view of the electrostatic chuck device 1 along the line segment A-A in Figure 1. Figure 5 is a perspective cross-sectional view of the electrostatic chuck device 1. In the following description, reference numerals shown in Figures 2 and 3 will be used as appropriate.

[0092] As shown in Figures 4 and 5, the electrostatic chuck device 1 is constructed by placing the rotating body 10 over the base 20 from above, and combining the rotating body 10 and the base 20 as described above.

[0093] In the configuration in which the rotating body 10 and the base 20 are combined, the protruding portions of the rotating body 10 and the base 20 are inserted into the recesses of the other component. Specifically, the protruding portion 121 of the rotating body 10 is inserted into the recess 216 of the base 20. Similarly, the protruding portion 123 is inserted into the recess 212, and the protruding portion 125 is inserted into the recess 218.

[0094] Furthermore, the protruding portion 211 of the base 20 is inserted into the recess 126 of the rotating body 10. Similarly, the protruding portion 217 is inserted into the recess 128.

[0095] The protruding portion 129 of the rotating body 10 faces the flange 219 of the base 20.

[0096] (First conductive section) In the base 20, a first ionic liquid IL1 (first conductive liquid) is stored in a space where the inner wall 23a of the bearing member 23 and the recess 221 of the insulating member 22 are in liquid-tight communication. An annular electrode 222 is positioned in the recess 221 at a location where it is immersed in the ionic liquid IL1, and wiring (not shown) is connected to the electrode 222.

[0097] The ionic liquid IL1, the recess 221 for storing the ionic liquid IL1, and the electrode 222 positioned within the recess 221 correspond to the "first conductive portion" in this invention. The first terminal 113 is inserted into the first conductive portion 231. The first terminal 113 and the electrode 222 are non-contacting, and are electrically connected via the ionic liquid IL1 that is in contact with them.

[0098] Ionic liquids possess conductivity, high heat resistance, and minimal change in physical properties due to temperature fluctuations. Furthermore, ionic liquids have extremely low vapor pressure and are less prone to volatilization in a vacuum environment. Therefore, even in the various environments anticipated for the use of the electrostatic chuck device 1, they can maintain their desired physical properties (fluidity, conductivity) without volatilization.

[0099] As the ionic liquid IL1, one that is liquid in the operating environment of the electrostatic chuck device 1 can be used. The ionic liquid IL1 may also be a room-temperature ionic liquid that is liquid at room temperature (25°C) and normal pressure (atmospheric pressure, 1013 hPa).

[0100] Ionic liquid IL1 is appropriately selected from known ionic liquids based on the desired fluidity (or viscosity) and conductivity. As ionic liquid IL1, for example, an ionic liquid consisting of N,N-diethyl-N-methyl-N-(2-methoxyethyl)ammonium (DEME) and bis(trifluoromethanesulfonyl)imide (TFSI) (formula (1) below) or 1-ethyl-3-methylimidazolium dicyanamide (formula (2) below) can be used.

[0101]

[0102]

[0103] As the ionic liquid IL1, only one type may be used, or two or more types may be used in combination.

[0104] The first conductive portion 231 functions as a fluid bearing (first fluid bearing HB1). The first fluid bearing HB1 rotatably holds the first terminal 113 via the ionic liquid IL1.

[0105] A high potential is applied to this first conductive portion 231 from the electrode 222. As a result, a high potential is applied to the first electrode 112A, which is an electrostatic adsorption electrode, via the first conductive portion 231.

[0106] (Second Conductive Section) The second conductive section 232 has an annular protrusion 211 provided concentrically with the central axis C, and a supply device 25. The protrusion 211 corresponds to the "first protrusion section" of the present invention.

[0107] The supply device 25 circulates and supplies the second ionic liquid IL2 (second conductive liquid) to the base 20. Specifically, the supply device 25 is connected to a through hole 211a (supply port 211A) provided in the base 20, and supplies the ionic liquid IL2 to the base 20 through the through hole 211a.

[0108] As the ionic liquid IL2, the compound described above as the ionic liquid IL1 can be used.

[0109] The ionic liquid IL2 is supplied to the top 211x of the protruding portion 211 through the through hole 211a. The ionic liquid IL2 fills the recess 211c provided in the top 211x and flows down from the top 211x along the inner surface 211y and outer surface 211z of the protruding portion 211.

[0110] Furthermore, the ionic liquid IL2 is also supplied to the inner surface 211y of the protruding portion 211 through the through hole 211b. The ionic liquid IL2 fills the recess 211d provided on the inner surface 211y and flows down the inner surface 211y.

[0111] The ionic liquid IL2 flowing down the inner surface 211y reaches the recess 216 and flows out of the base 20 through the through hole 216a provided in the recess 216. Similarly, the ionic liquid IL2 flowing down the outer surface 211z reaches the recess 218 and flows out of the base 20 through the through hole 218a provided in the recess 218.

[0112] The supply device 25 is connected to through holes 216a and 218a provided in the base 20, and recovers the ionic liquid IL2 through the through holes 216a and 218a. The recovered ionic liquid IL2 is then supplied back to the base 20 by the supply device 25.

[0113] In this second conductive portion 232, the ionic liquid IL2 at the top portion 211x is sandwiched between the top portion 211x and the lower surface of the rotating stage 12. The lower end of the second terminal 114 is in contact with the ionic liquid IL2 at the top portion 211x and is electrically connected via the ionic liquid IL2. The base body 21 of the base 20 through which the ionic liquid IL2 flows is conductive and connected to GND. Therefore, the second electrode 112B functions as a GND electrode.

[0114] Furthermore, at the top portion 211x, the ionic liquid IL2 rotatably supports the rotating stage 12 (rotating body 10). As a result, the second conductive portion 232 functions as a fluid bearing (second fluid bearing HB2) that rotatably supports the rotating stage 12 via the ionic liquid IL2.

[0115] When the rotating body 10 is rotated, it is assumed that as the rotation speed increases, the ionic liquid IL2 at the top portion 211x will be ejected radially outward due to centrifugal force. At this time, a protruding ridge 125 is positioned on the radially outward side of the top portion 211x. Therefore, the ionic liquid IL2 ejected from the top portion 211x collides with the slope 125a of the protruding ridge 125, falls into the recess 218, and is recovered.

[0116] Furthermore, the upper end (upper surface, +z side end) of the protruding portion 217 is located above the lower end (lower surface, -z side end) of the protruding portion 125 of the rotating body 10. This prevents the ionic liquid IL2 from overflowing the protruding portion 217 inserted into the recess 128 and leaking outside the device, even when the rotating body 10 is rotated at high speed.

[0117] Furthermore, the rotating stage 12 has a protruding portion 121 that faces the inner surface 211y with a gap between them. The protruding portion 121 corresponds to the "second protruding portion" in this invention. The ionic liquid IL2 that flows down the inner surface 211y is sandwiched between the inner surface 211y and the outer surface 121y of the protruding portion 121.

[0118] In the second conductive portion 232, the ionic liquid IL2 can be supplied to the gap between the inner surface 211y and the outer surface 121y through the through hole 211b. With this configuration, contact between the inner surface 211y and the outer surface 121y is suppressed, allowing the rotating body 10 to rotate stably.

[0119] [Rotation Mechanism] The electrostatic chuck device 1 is equipped with a rotation mechanism 30 that rotates the rotating body 10 in the circumferential direction of the central axis C. The rotation mechanism 30 is equipped with a magnet 31 provided on the rotating body 10 and a coil 33 provided on the base 20. The magnet 31 and the coil 33 are positioned opposite each other with a gap between them when the rotating body 10 is placed over the base 20.

[0120] The magnet 31 is provided on the inner surface 121x of the protruding portion 121 of the rotating body 10 and is arranged in the circumferential direction of the central axis C. More specifically, a rotor core 32 made of magnetic material is provided on the inner surface 121x of the protruding portion 121, and the magnet 31 is arranged on the surface of the rotor core 32.

[0121] The magnet 31 may be a plurality of magnets arranged in a ring shape along the inner surface 121x, or it may be a single magnet formed in a ring shape.

[0122] Multiple coils 33 are provided on the protruding ridges 213 of the base 20 and are arranged in the circumferential direction of the central axis C. The coils 33 are wound around multiple teeth of a stator core (not shown).

[0123] In other words, the electrostatic chuck device 1 having a rotating mechanism 30 functions as a radial gap type outer rotor motor, in which the magnet 31 and coil 33 are arranged radially with a gap between them. When the electrostatic chuck device 1 is viewed as an outer rotor type motor, the rotating body 10 functions as the rotor and the base 20 functions as the stator.

[0124] In this configuration, a coolant gas may be flowed into the recess 214 located below the coil 33 to cool the coil 33.

[0125] (Main effect) In the electrostatic chuck device 1 with this configuration, the terminals (first terminal 113, second terminal 114) are arranged rotationally symmetrically with respect to the central axis C. Therefore, the electrostatic chuck device 1 can be made capable of stably rotating the rotating body 10.

[0126] Furthermore, in the electrostatic chuck device 1, multiple second terminals 114 are connected to the second electrode 112B, which is the GND electrode, and the multiple second terminals 114 are arranged rotationally symmetrically. In order for the second electrode 112B to function as a GND electrode, only one second terminal 114 is needed, but in this embodiment, multiple second terminals 114 are deliberately used. This makes it possible to arrange the second terminals 114 rotationally symmetrically with respect to the central axis C.

[0127] Furthermore, in the electrostatic chuck device 1, an ionic liquid is used as the fluid in the fluid bearings (first fluid bearing HB1, second fluid bearing HB2) that support the rotating body 10 on the base 20. Therefore, the electrostatic chuck device 1 can be used suitably even in a vacuum environment, as the functions of the fluid bearings and conductive parts are less likely to be impaired.

[0128] According to the electrostatic chuck device 1 configured as described above, the held plate-shaped sample can be rotated in the circumferential direction.

[0129] Furthermore, the rotating body 10 described above is a novel rotating body that can be used in an electrostatic chuck device 1 to hold a plate-shaped sample and rotate in the circumferential direction.

[0130] Such an electrostatic chuck device 1 can be used in various equipment configurations, such as film deposition equipment (sputtering, CVD, etc.), etching equipment, cleaning equipment, and wet polishing equipment (CMP, wet cleaning).

[0131] In this embodiment, the first electrode 112A is a circular electrostatic adsorption electrode and the second electrode 112B is an annular GND electrode, but the invention is not limited to this. For example, the first and second electrodes of the internal electrode may be composed of a pair of comb-shaped electrodes, with one comb-shaped electrode as the positive electrode and the other as the negative electrode, forming a hyperbolic electrode. In this case, the first and second electrodes (the pair of comb-shaped electrodes) function as electrostatic adsorption electrodes. In this case, it is advisable to cover both comb-shaped electrodes, the terminals connected to the comb-shaped electrodes, and the wiring with insulating material to insulate them from the metal rotating plate and base.

[0132] In the above configuration, it is preferable that there are multiple first terminals connected to the first electrode, and that the entire set of terminals, including the first and second terminals, is arranged rotationally symmetrically with respect to the central axis C. Furthermore, it is preferable that the first conductive portion connected to the first terminal in the base 20 has the same configuration as the second conductive portion.

[0133] Furthermore, in the above configuration, if the first terminal and the second terminal are the same size and have the same mass, then when considering the above symmetry, the first terminal and the second terminal can be considered equivalent. For example, if we assume a virtual circle with a center that coincides with the central axis C in a plan view, and the first and second terminals are arranged at equal intervals on this virtual circle, then if the first and second terminals can be considered equivalent, the arrangement of the first and second terminals on the virtual circle is arbitrary. In this case, the number of first terminals and the number of second terminals may be the same or different.

[0134] Furthermore, in this embodiment, the configuration of the rotation mechanism 30 allows the electrostatic chuck device 1 to function as a radial gap type outer rotor motor, but it is not limited to this. For example, in the electrostatic chuck device, the coil 33 may be placed below the magnet 31, and the magnet 31 and the coil 33 may be spaced apart in the direction of the central axis, thus configuring a so-called axial gap type outer rotor motor.

[0135] Furthermore, the rotating mechanism 30 can also be configured as an inner rotor type motor in which a coil 33 is arranged on the outside of a magnet 31 that is an annular shape in plan view. Moreover, as in the electrostatic chuck device 1 of this embodiment, the configuration is not limited to one in which a part of the electrostatic chuck device functions as a motor to rotate the rotating stage. In addition, a separate motor (rotating mechanism) may be provided as the power source for rotating the rotating stage, and the rotating stage may be rotated by this separate motor.

[0136] Furthermore, although the electrostatic chuck device 1 has a protruding portion 121 facing the inner surface 211y of the protruding portion 211, the rotating body 10 may have a protruding portion facing the outer surface 211z. In this case, the protruding portion 211 has a through hole extending from the through hole 211a to the outer surface 211z, and the supply device 25 may supply the ionic liquid IL2 to the gap between the outer surface 211z of the protruding portion 211 and the protruding portion corresponding to the outer surface 211z. This allows the second fluid bearing HB2 to function optimally.

[0137] Furthermore, the electrostatic chuck device 1 may incorporate a heater electrode as an internal electrode for heating the plate-shaped sample held on the mounting surface 11s. In this case, a terminal for supplying current to the heater electrode is provided, similar to the second terminal 114 described above, and the base 20 is provided with a configuration similar to the second conductive portion 232, which is connected to the terminal that connects to the heater electrode.

[0138] The presence of a heater in the electrostatic chuck device 1 facilitates temperature control of the plate-shaped sample being held. For example, when using the electrostatic chuck device 1 of this embodiment in a process of treating a plate-shaped sample with a chemical solution at a predetermined temperature, the processing temperature can be easily controlled appropriately, and the processing can be carried out efficiently.

[0139] Furthermore, while the electrostatic chuck device 1 is designed to have an ionic liquid in its conductive portion, it is not limited to this. Other conductive liquids can be used in place of the ionic liquid in the conductive portion. Examples of such conductive liquids include liquid metals such as gallium alloy (Gallinstan). In the conductive portion, either or both of the first conductive portion 231 and the second conductive portion 232 may have an ionic liquid.

[0140] Preferred embodiments of the present invention have been described above with reference to the attached drawings, but the present invention is not limited to these examples. The shapes and combinations of the constituent members shown in the above examples are merely examples, and can be modified in various ways based on design requirements, etc., without departing from the spirit of the present invention.

[0141] 1...Electrostatic chuck device, 10...Rotating body, 11...Electrostatic chuck member, 12...Rotating stage, 20...Base, 25...Supply device, 30...Rotation mechanism, 31...Magnet, 33...Coil, 111...Dielectric substrate, 112...Internal electrode, 112A...First electrode, 112B...Second electrode, 113...First terminal (terminal), 114, 114A, 114B, 114C...Second terminal (terminal) Child), 121... protruding part (second protruding part), 211... protruding part (first protruding part), 211x... top, 211y... inner surface, 211z... outer surface, 231... first conductive part, 232... second conductive part, C... central axis, HB1... first fluid bearing, HB2... second fluid bearing, IL1... first ionic liquid (first conductive liquid), IL2... second ionic liquid (second conductive liquid)

Claims

1. An electrostatic chuck device comprising: an electrostatic chuck member; a rotating stage for holding the electrostatic chuck member; a rotating body rotatable in the circumferential direction of a central axis through which it passes; a base positioned in the axial direction of the central axis; and a rotation mechanism for rotating the rotating body in the circumferential direction of the central axis, wherein the electrostatic chuck member comprises: a dielectric substrate; an internal electrode enclosed in the dielectric substrate; and terminals connected to the internal electrode; the base has a conductive portion that is in electrical contact with the internal electrode; the internal electrode comprises a first electrode and a second electrode; the terminal comprises: one or more first terminals connected to the first electrode; and one or more second terminals connected to the second electrode; the conductive portion comprises: a first conductive portion connected to the first terminal via a first conductive liquid; and a second conductive portion connected to the second terminal via a second conductive liquid; and the terminals are arranged rotationally symmetrically with respect to the central axis.

2. The electrostatic chuck device according to claim 1, wherein the first electrode is provided so as to overlap with the central axis in a plan view, the second electrode is provided radially outward from the central axis relative to the first electrode, one first terminal is provided so as to overlap with the central axis, and a plurality of second terminals are arranged rotationally symmetrically with respect to the central axis.

3. The electrostatic chuck device according to claim 1 or 2, wherein the first electrode is a cylindrical member that penetrates the rotating stage and extends in the direction of the central axis, and the first conductive portion is a first fluid bearing that rotatably holds the first terminal via the first conductive liquid.

4. The electrostatic chuck device according to claim 1 or 2, wherein the second conductive portion comprises an annular first protrusion provided concentrically with the central axis, and a supply device that supplies the second conductive liquid to at least the top of the first protrusion, and the second fluid bearing that rotatably supports the rotating stage via the second conductive liquid supplied to the top.

5. The electrostatic chuck device according to claim 4, wherein the rotating stage is provided concentrically with the central axis and has a second protrusion that faces the inner or outer surface of the first protrusion with a gap between them, and the supply device supplies the second conductive liquid into the gap between the first protrusion and the second protrusion.

6. The electrostatic chuck device according to claim 1 or 2, wherein the rotating mechanism comprises a magnet provided on the rotating body and arranged in the circumferential direction of the central axis, and a plurality of coils provided on the base, facing the magnet with a gap between them and arranged in the circumferential direction of the central axis.

7. The electrostatic chuck device according to claim 1 or 2, wherein either or both of the first conductive liquid and the second conductive liquid are ionic liquids.

8. A rotating body comprising an electrostatic chuck member and a rotating stage that holds the electrostatic chuck member and is rotatable around a central axis through which it passes, wherein the electrostatic chuck member has a dielectric substrate, an internal electrode enclosed in the dielectric substrate, and terminals connected to the internal electrode, the internal electrode has a first electrode and a second electrode, the terminal has one or more first terminals connected to the first electrode and one or more second terminals connected to the second electrode, and the terminal is a rotating body arranged rotationally symmetrically with respect to the central axis.

9. The rotating body according to claim 8, wherein the first electrode is provided so as to overlap with the central axis in a plan view, the second electrode is provided radially outward from the central axis relative to the first electrode, one first terminal is provided so as to overlap with the central axis, and a plurality of second terminals are arranged rotationally symmetrically with respect to the central axis.

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