Electrostatic chuck device

Abstract

An electrostatic chuck device includes: a plate-shaped electrostatic chuck portion supporting a plate-shaped sample through a placement surface facing one side in a thickness direction and having an internal electrode for electrostatic adsorption embedded therein; a base part which supports the electrostatic chuck part from the other side in the thickness direction and cools the electrostatic chuck part; an adhesive layer located between the electrostatic chuck part and the base part and having a first adhesive part for fixing the electrostatic chuck part and the base part; and a cylindrical insulator, in which a first through-hole extending in the thickness direction is provided in the electrostatic chuck part, a second through-hole extending in the thickness direction and communicating with the first through-hole is provided in the base part, the insulator is disposed in the second through-hole, and the base part has a facing surface facing the electrostatic chuck part. And a curved surface located at the opening of the second through hole and connected to the facing surface.

Description

Technical Field

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

[0002] This application claims priority based on Japanese Patent Application No. 2022-209541 filed on December 27, 2022, and the content thereof is incorporated herein by reference. Background Art

[0003] In semiconductor manufacturing devices, an electrostatic chuck device that fixes a plate-like specimen such as a wafer or a glass substrate to a chuck surface is used. The electrostatic chuck device includes an electrostatic chuck portion having an electrostatic adsorption mechanism, a base portion that cools the electrostatic chuck portion, and an adhesive layer that bonds the electrostatic chuck portion and the base portion. A through-hole for introducing a cooling gas is provided in such an electrostatic chuck device (for example, Patent Document 1).

[0004] Prior Art Documents

[0005] Patent Documents

[0006] Patent Document 1: Japanese Unexamined Patent Application Publication No. 2004-31665 Summary of the Invention

[0007] Technical Problem to be Solved by the Invention

[0008] In order to improve the cooling efficiency using a cooling gas, for example, it is conceivable to increase the through-hole to increase the heat absorption amount of the cooling gas in the base portion. However, in this case, problems such as discharge from the base portion or the electrostatic chuck portion may easily occur due to the enlargement of the through-hole. That is, in order to improve the cooling efficiency of the plate-like specimen using the cooling gas, it is necessary to solve such problems.

[0009] The present invention has been completed in view of such circumstances, and one of its objects is to provide an electrostatic chuck device that suppresses discharge and improves cooling efficiency.

[0010] Means for Solving the Technical Problem

[0011] In order to solve the above problems, one aspect of the present invention includes the following aspects. Two or more of the following inventions can be combined with each other.

[0012] [1] An electrostatic chuck device, comprising: a plate-shaped electrostatic chuck portion that supports a plate-shaped specimen on a mounting surface facing one side in the thickness direction and incorporates an internal electrode for electrostatic adsorption; a base portion that supports the electrostatic chuck portion from the other side in the thickness direction and cools the electrostatic chuck portion; an adhesive layer that is located between the electrostatic chuck portion and the base portion and has a first adhesive portion for fixing the electrostatic chuck portion and the base portion; and a cylindrical insulator. A first through hole extending in the thickness direction is provided in the electrostatic chuck portion, a second through hole extending in the thickness direction and communicating with the first through hole is provided in the base portion, and the insulator is disposed in the second through hole. The base portion has an opposing surface opposing the electrostatic chuck portion and has a curved surface located at an opening of the second through hole and connected to the opposing surface.

[0013] [2] The electrostatic chuck device according to [1], wherein

[0014] The radius of curvature of the curved surface in a cross section along the central axis of the second through hole is greater than the thickness dimension of the internal electrode for electrostatic adsorption.

[0015] [3] The electrostatic chuck device according to [1] or [2], wherein

[0016] The radius of curvature of the curved surface in a cross section along the central axis of the second through hole is greater than the thickness dimension of the first adhesive portion.

[0017] [4] The electrostatic chuck device according to any one of [1] to [3], wherein the radius of curvature of the curved surface in a cross section along the central axis of the second through hole is 10 μm or more.

[0018] [5] The electrostatic chuck device according to any one of [1] to [4], wherein the adhesive layer covers the entire curved surface.

[0019] [6] The electrostatic chuck device according to [5], wherein

[0020] One end face on one side in the thickness direction of the insulator is located at a position closer to the other side in the thickness direction than an end portion on the other side in the thickness direction of the curved surface and the second through hole, and the adhesive layer has a second adhesive portion located between the end face of the insulator and the electrostatic chuck portion.

[0021] [7] The electrostatic chuck device according to [6], wherein

[0022] The thickness dimension of the second adhesive portion is 2 times or more the thickness dimension of the first adhesive portion.

[0023] [8] The electrostatic chuck device according to [6] or [7], wherein,

[0024] The size of the second bonding portion in the radial direction of the second through hole is larger than the thickness of the first bonding portion.

[0025] [9] The electrostatic chuck device according to any one of [5] to [8], wherein,

[0026] The bonding layer has a third bonding portion, and the third bonding portion is between the inner peripheral surface of the second through hole and the outer peripheral surface of the insulator and fixes the insulator to the inner peripheral surface of the second through hole.

[0027]

[10] The electrostatic chuck device according to any one of [1] to [9], wherein,

[0028] The volume inside the insulator is more than 5 times the volume inside the first through hole.

[0029]

[11] The electrostatic chuck device according to any one of [1] to

[10] , wherein,

[0030] The arithmetic mean roughness Ra of the inner peripheral surface of the insulator is greater than the arithmetic mean roughness Ra of the inner peripheral surface of the first through hole.

[0031]

[12] The electrostatic chuck device according to

[11] , wherein,

[0032] The arithmetic mean roughness Ra of the inner peripheral surface of the insulator is 2 times or more the arithmetic mean roughness Ra of the inner peripheral surface of the first through hole.

[0033]

[13] The electrostatic chuck device according to

[11] or

[12] , wherein,

[0034] The arithmetic mean roughness Ra of the inner peripheral surface of the insulator is 1.5 μm or more, and the arithmetic mean roughness Ra of the inner peripheral surface of the first through hole is 0.5 μm or less.

[0035]

[14] The electrostatic chuck device according to any one of [1] to

[13] , wherein,

[0036] A conical surface with a diameter decreasing as it faces one side in the thickness direction is provided on the inner peripheral surface of the insulator.

[0037]

[15] The electrostatic chuck device according to any one of [1] to

[14] , wherein,

[0038] A chamfered portion is provided at the boundary between the opposed surface and the inner peripheral surface of the second through hole, and the curved surface is connected to the opposed surface and the chamfered portion.

[0039] Effect of the Invention

[0040] According to the present invention, an electrostatic chuck device capable of suppressing discharge and improving cooling efficiency can be provided. Description of the Drawings

[0041] Figure 1 It is a schematic cross-sectional view showing an example of the electrostatic chuck device of the first embodiment.

[0042] Figure 2 is Figure 1 a schematic enlarged view of Region II of

[0043] Figure 3 It is a schematic cross-sectional view showing a modified example of the curved surface that can be adopted in the first embodiment.

[0044] Figure 4 It is a schematic explanatory view showing an example of the semiconductor manufacturing apparatus of the first embodiment.

[0045] Figure 5 It is a schematic cross-sectional enlarged view showing an example of the electrostatic chuck device of the second embodiment.

[0046] Figure 6 It is a schematic cross-sectional enlarged view showing an example of the electrostatic chuck device of the third embodiment.

[0047] Figure 7 It is a schematic cross-sectional enlarged view showing an example of the electrostatic chuck device of the fourth embodiment.

[0048] Figure 8 It is a schematic cross-sectional enlarged view showing an example of the electrostatic chuck device of the fifth embodiment.

[0049] Figure 9 It is a schematic cross-sectional enlarged view showing a modified example of the electrostatic chuck device of the fifth embodiment. Detailed Description of the Invention

[0050] Hereinafter, examples of embodiments of the present invention will be described while referring to the attached Figure 1 In addition, in the drawings used in the following description, in order to facilitate understanding of the features, parts that become the features are sometimes enlarged and shown for convenience, and the dimensional ratios of the respective components are not necessarily the same as the actual ones.

[0051] <First Embodiment>

[0052] Figure 1 It is a cross-sectional view of the electrostatic chuck device 1 of the first embodiment. And, Figure 2 is Figure 1 an enlarged view of Region II of

[0053] The electrostatic chuck device 1 includes an electrostatic chuck portion 2, a base portion 3, an adhesive layer 4, and an insulator 40. The electrostatic chuck portion 2 is plate-shaped and supports a plate-shaped specimen W on a mounting surface 2a on one side in the thickness direction Z. The electrostatic chuck portion 2 adsorbs the plate-shaped specimen W by an internal electrode 13 for electrostatic adsorption provided therein. The base portion 3 supports the electrostatic chuck portion 2 from the other side in the thickness direction Z. The base portion 3 cools the electrostatic chuck portion 2. The adhesive layer 4 is located between the electrostatic chuck portion 2 and the base portion 3. The insulator 40 is cylindrical and fixed to the base portion 3.

[0054] Hereinafter, each part of the electrostatic chuck device 1 of the present embodiment will be described in detail.

[0055] In this specification, each part is described based on the thickness direction Z of the electrostatic chuck portion 2. That is, the direction in which the mounting surface 2a of the electrostatic chuck portion 2 faces is taken as one side in the thickness direction Z, and the opposite side is referred to as the other side in the thickness direction. And, in this specification, the relative positional relationship of the electrostatic chuck device 1 may be described in a posture in which one side in the thickness direction Z faces upward. The up and down directions in the following description are directions in an example of the posture when using the electrostatic chuck device 1, and do not limit the posture of the electrostatic chuck device 1 during use.

[0056] (Electrostatic chuck portion)

[0057] The electrostatic chuck portion 2 has a structure in which a mounting plate 11, an internal electrode 13 for electrostatic adsorption, and an insulating material layer 14 surrounding the peripheral portion of the internal electrode 13 for electrostatic adsorption are laminated in this order from the upper side, and a support plate 12. And, the electrostatic chuck portion 2 has a power supply terminal 15 that penetrates the adhesive layer 4 and the base portion 3 and applies a voltage to the internal electrode 13 for electrostatic adsorption.

[0058] The electrostatic chuck portion 2 has: a mounting plate 11 that is circular in plan view, with the upper surface being a mounting surface 2a for mounting a plate-shaped specimen W such as a semiconductor wafer; a circular support plate 12 disposed opposite to the lower surface side of the mounting plate 11; a circular internal electrode 13 for electrostatic adsorption, which is clamped between the mounting plate 11 and the support plate 12 and has a diameter smaller than that of the mounting plate 11 and the support plate 12; and a power supply terminal 15 that is connected to the lower surface of the internal electrode 13 for electrostatic adsorption and applies a DC voltage.

[0059] The mounting plate 11 and the support plate 12 are formed of a ceramic sintered body having mechanical strength and insulation durability against corrosive gases and their plasmas, such as an alumina-silicon carbide (Al2O3-SiC) composite sintered body, an alumina (Al2O3) sintered body, an aluminum nitride (AlN) sintered body, a yttrium oxide (Y2O3) sintered body, etc. Since the mounting plate 11 constitutes the mounting surface 2a on the upper side, a material having a particularly high dielectric constant is preferably used, and it is composed of a material that does not become an impurity with respect to the plate-shaped specimen W for electrostatic adsorption. From this viewpoint, as the constituent material of the mounting plate 11, a silicon carbide-aluminum oxide composite sintered body containing 4% by weight or more and 20% by weight or less of silicon carbide and the balance being alumina is preferably used. The materials of the mounting plate 11 and the support plate 12 may be the same, different, or at least partially different, but are preferably the same.

[0060] As Figure 2 shown, a plurality of protrusions 16 having a diameter smaller than the thickness of the plate-shaped specimen W are formed on the mounting surface 2a of the mounting plate 11, and these protrusions 16 support the plate-shaped specimen W.

[0061] The internal electrode 13 for electrostatic adsorption is located on the lower side of the mounting plate 11. The internal electrode 13 for electrostatic adsorption is used as an electrode for an electrostatic chuck for generating charges and fixing the plate-shaped specimen W by electrostatic adsorption force, and its shape or size is appropriately adjusted according to its use. For example, the internal electrode 13 for electrostatic adsorption is provided as an electrode having a predetermined pattern on the surface of the layer forming the internal electrode 13 for electrostatic adsorption, for example, at the forming position. In addition, the internal electrode 13 for electrostatic adsorption also functions even when it is provided as a so-called entire surface electrode having no pattern.

[0062] The internal electrode 13 for electrostatic adsorption can be formed by forming a metal foil on the support plate 12 by sputtering or evaporation. As another example, it can also be formed by coating a composite material of a conductive material and an organic substance, which is a forming material of the internal electrode 13 for electrostatic adsorption, using a coating method such as screen printing.

[0063] The internal electrode 13 for electrostatic adsorption can be formed of electroconductive ceramics such as alumina-tantalum carbide (Al2O3-Ta4C5) electroconductive composite sintered body, alumina-tungsten (Al2O3-W) electroconductive composite sintered body, alumina-silicon carbide (Al2O3-SiC) electroconductive composite sintered body, aluminum nitride-tungsten (AlN-W) electroconductive composite sintered body, aluminum nitride-tantalum (AlN-Ta) electroconductive composite sintered body, yttrium oxide-molybdenum (Y2O3-Mo) electroconductive composite sintered body, etc., or high melting point metals such as tungsten (W), tantalum (Ta), molybdenum (Mo). Further, the internal electrode 13 for electrostatic adsorption can also be formed of copper (Cu), aluminum (Al), or carbon (C). The thickness dimension d1 of the internal electrode 13 for electrostatic adsorption is not particularly limited, and is usually selected to be 3 μm or more and 200 μm or less, more preferably 10 μm or more and 100 μm or less. It can also be 20 μm or more and 80 μm or less, or 40 μm or more and 60 μm or less, etc.

[0064] The insulating material layer 14 is used to integrally bond the mounting plate 11 and the support plate 12, and protect the internal electrode 13 for electrostatic adsorption from the influence of plasma. As the material constituting the insulating material layer 14, it is preferable to include or use an insulating material having the same main component as the mounting plate 11 and the support plate 12. For example, when the mounting plate 11 and the support plate 12 are formed of a silicon carbide-alumina composite sintered body, it is preferably alumina (Al2O3).

[0065] The power supply terminal 15 is a rod-shaped terminal provided to apply a DC voltage to the internal electrode 13 for electrostatic adsorption. As the material for forming the power supply terminal 15, as long as it is an electroconductive material with excellent heat resistance, there is no particular limitation, and a metal material or an electroconductive organic material can be used. The power supply terminal 15 is insulated from the base portion 3.

[0066] (Base portion)

[0067] The base portion 3 is provided on the lower side of the electrostatic chuck portion 2, and controls the temperature of the electrostatic chuck portion 2 to a desired temperature. The base portion 3 has a facing surface 3a facing the electrostatic chuck portion 2. The facing surface 3a is the upper surface of the base portion 3. The base portion 3 supports the electrostatic chuck portion 2 by the facing surface 3a.

[0068] The base portion 3 also functions as an electrode for high-frequency generation. A flow path 21 for circulating a cooling medium such as water or an organic solvent is formed inside the base portion 3. Thus, the base portion 3 cools the electrostatic chuck portion 2 and maintains the temperature of the plate-shaped specimen W placed on the placement surface 2a at a desired temperature. Further, the base portion 3 cools the cooling gas C described later and cools the plate-shaped specimen W via the cooling gas C.

[0069] The base portion 3 contains aluminum (Al) or an aluminum alloy. At least the surface of the base portion 3 exposed to the plasma is preferably treated with an alumina film or an insulating film such as alumina is formed thereon. Thereby, in addition to improving the plasma resistance, abnormal discharge is also prevented, and thus the plasma resistance stability is improved. Also, since the surface is not easily damaged, the occurrence of damage can be prevented. In addition, as long as the base portion 3 is a metal material with good thermal conductivity, its material is not limited, and for example, copper (Cu), a copper alloy, stainless steel (SUS), etc. can also be used.

[0070] (Adhesive layer)

[0071] The adhesive layer 4 has a first adhesive portion 4a, a second adhesive portion 4b, and a remaining portion 4e. The first adhesive portion 4a is located between the opposed surface 3a of the base portion 3 and the lower surface 2b of the electrostatic chuck portion 2. The first adhesive portion 4a fixes the electrostatic chuck portion 2 and the base portion 3. The thickness dimension t1 of the first adhesive portion 4a is, for example, 20 μm or more and 300 μm or less. It can also be 40 μm or more and 250 μm or less, or 50 μm or more and 200 μm or less, or 100 μm or more and 150 μm or less, etc.

[0072] The second adhesive portion 4b is disposed between the upper end surface 40a of the insulator 40 and the lower surface 2b of the electrostatic chuck portion 2. In the present embodiment, the thickness dimension of the second adhesive portion 4b is substantially equal to the thickness dimension of the first adhesive portion 4a. The remaining portion 4e is a portion adhered to the lower surface 2b of the electrostatic chuck portion 2 in a region radially inward of the inner peripheral surface 40b of the insulator 40. The remaining portion 4e can also be removed.

[0073] The adhesive layer 4 is preferably composed of an adhesive having heat resistance in the temperature range of -20°C to 150°C. As the adhesive constituting the adhesive layer 4, for example, an acrylic resin, a silicone resin, an epoxy resin, etc. are preferably used. Especially in the case of using oxygen-based plasma, a silicone resin having excellent plasma resistance with respect to oxygen-based plasma is preferably used.

[0074] In the present embodiment, it is preferable that the first adhesive portion 4a and the second adhesive portion 4b are composed of a single adhesive. However, the first adhesive portion 4a and the second adhesive portion 4b can also be respective portions including different adhesives formed by different processes. As an example, the first adhesive portion 4a can be formed by curing a sheet-like adhesive, and the second adhesive portion 4b can be formed by curing a liquid adhesive.

[0075] (Cooling gas inlet hole)

[0076] In the electrostatic chuck portion 2, the base portion 3, and the adhesive layer 4, a plurality of pin through holes 30B and cooling gas introduction holes 30 that penetrate these vertically are provided. A lifting pin 22 that assists in the detachment of the plate-like specimen W adsorbed on the placement surface 2a penetrates through the pin through hole 30B. A drive unit (not shown) is connected to the lower end of the lifting pin 22, and the lifting pin 22 is driven up and down along the penetration direction of the pin through hole 30B. In the present embodiment, the structure of the pin through hole 30B is set to the structure of the cooling gas introduction hole 30. According to the present embodiment, the processes of forming the pin through hole 30B and the cooling gas introduction hole 30 can be made common, and the manufacturing cost of the electrostatic chuck device 1 can be reduced. In addition, there may be cases where the pin through hole 30B provided with the lifting pin 22 also serves as a cooling gas introduction hole and cases where it does not, and various selections can be made according to the design conditions.

[0077] The cooling gas introduction hole 30 is provided to supply a cooling gas C such as helium (He) to the plate-like specimen W placed on the electrostatic chuck portion 2. The cooling gas introduction hole 30 has a first through hole 31 that is a part penetrating the electrostatic chuck portion 2 and a second through hole 32 that is a part penetrating the base portion 3. That is, the first through hole 31 is provided in the electrostatic chuck portion 2, the second through hole 32 is provided in the base portion 3, and the first through hole 31 and the second through hole 32 communicate with each other to form the cooling gas introduction hole 30.

[0078] The first through hole 31 and the second through hole 32 are circular when viewed in the thickness direction Z. In the present embodiment, the extending directions of the first through hole 31 and the second through hole 32 are the same as the thickness direction Z. However, if the first through hole 31 and the second through hole 32 extend along the thickness direction Z, they may also extend obliquely with respect to the thickness direction Z. Also, the extending directions of the first through hole 31 and the second through hole 32 may not be parallel to each other. The central axes J of the first through hole 31 and the second through hole 32 of the present embodiment coincide with each other. However, if the first through hole 31 and the second through hole 32 communicate with each other, the central axes may also be offset from each other.

[0079] A cylindrical insulator 40 is disposed in the second through hole 32. The inner diameter of the second through hole 32 is larger than the inner diameter of the first through hole 31. A curved surface 3f is provided at the upper opening of the second through hole 32. The curved surface 3f will be described in detail in the subsequent section.

[0080] The second through hole 32 has an inner peripheral surface 32a that surrounds the central axis J. In this specification, the inner peripheral surface 32a of the second through hole 32 refers to the cylindrical surface that extends around the central axis J of the second through hole 32, and it is assumed that the curved surface 3f is not included in the inner peripheral surface 32a of the second through hole 32.

[0081] (Insulator)

[0082] The insulator 40 includes, for example, ceramics. The insulator 40 has durability against plasma. As the ceramics constituting the insulator 40, ceramics containing one selected from aluminum nitride (AlN), aluminum oxide (Al2O3), silicon nitride (Si3N4), zirconium oxide (ZrO2), sialon, boron nitride (BN), and silicon carbide (SiC) or composite ceramics containing two or more of them can be used.

[0083] In the present embodiment, the upper end surface 40a of the insulator 40 is disposed on a plane substantially the same as the opposed surface 3a (upper surface) of the base portion 3. The outer diameter of the insulator 40 is substantially equal to the inner diameter of the second through hole 32. The outer peripheral surface 40c of the insulator 40 is fixed to the inner peripheral surface 32a of the second through hole 32. The insulator 40 can be fixed to the second through hole 32 by fitting or can be fixed by adhesion.

[0084] The length of the insulator 40 is substantially equal to the length of the second through hole 32 and is greater than the length of the first through hole 31. Also, the inner diameter of the insulator 40 is greater than the inner diameter of the first through hole 31. The inner diameter of the insulator 40 is preferably 2 times or more the inner diameter of the first through hole 31. For example, it can be 1.2 times or more, etc., but is not limited to these examples. The cooling gas C flows upward in the interior V2 of the insulator 40 and enters the interior V1 of the first through hole 31. The cooling gas C further flows upward in the interior V1 of the first through hole 31 and is blown upward from the upper opening. Regarding the flow path length of the cooling gas C, the interior V2 of the insulator 40 is longer than the interior V1 of the first through hole 31. Regarding the flow path cross-sectional area of the cooling gas C, the interior V2 of the insulator 40 is larger than the interior V1 of the first through hole 31. Therefore, the volume of the interior V2 of the insulator 40 is larger than the volume of the interior V1 of the first through hole 31.

[0085] The volume V2 of the interior of the insulator 40 is preferably more than five times the volume V1 of the interior of the first through hole 31. The cooling gas C is cooled by the base portion 3 via the insulator 40 when passing through the interior V2 of the insulator 40. By increasing the volume V1 of the interior of the insulator 40, the area of the inner peripheral surface 40b in contact with the cooling gas C is enlarged, so that the temperature of the cooling gas C can be further reduced. On the other hand, if the volume V1 of the first through hole 31 is increased, the contact area between the cooling gas C and the electrostatic chuck portion 2 becomes larger, thereby promoting the heating of the cooling gas C by the electrostatic chuck portion 2 and increasing the temperature of the cooling gas C. Furthermore, if the inner diameter of the first through hole 31 becomes larger, the flow rate of the cooling gas C blown from the upper opening of the first through hole 31 to the lower side of the plate-like specimen W decreases, and the cooling efficiency using the cooling gas C may decrease. According to the present embodiment, by setting the volume V2 of the interior of the insulator 40 to be more than five times the volume V1 of the interior of the first through hole 31, it is possible to ensure the flow rate of the cooling gas C while reducing the temperature of the cooling gas C, and to improve the cooling efficiency of the plate-like specimen W.

[0086] In the present embodiment, the arithmetic mean roughness Ra of the inner peripheral surface 40b of the insulator 40 is preferably greater than the arithmetic mean roughness Ra of the inner peripheral surface 31a of the first through hole 31. As described above, the heat of the cooling gas C passing through the cooling gas introduction hole 30 moves to the base portion 3 via the inner peripheral surface 40b of the insulator 40. Therefore, by increasing the arithmetic mean roughness Ra of the inner peripheral surface 40b of the insulator 40 to increase the surface area of the inner peripheral surface 40b, more heat is transferred from the cooling gas C to the base portion 3, so that the cooling efficiency of the cooling gas C can be improved. On the other hand, if the arithmetic mean roughness Ra of the first through hole 31 is increased, the contact area between the cooling gas C and the electrostatic chuck portion 2 becomes larger, thereby promoting the heating of the cooling gas C by the electrostatic chuck portion 2. Also, if the arithmetic mean roughness Ra of the inner peripheral surface 31a of the first through hole 31 is increased, the fine particles generated during the processing of the plate-like specimen W are likely to accumulate on the inner peripheral surface ¾1a. The fine particles accumulated on the inner peripheral surface 31a of the first through hole 31 may suddenly peel off and have an adverse effect on the processing of the plate-like specimen W. According to the present embodiment, it is possible to suppress the accumulation of fine particles on the inner peripheral surface 31a of the first through hole 31 while ensuring a large surface area of the inner peripheral surface of the insulator 40 to improve the cooling efficiency of the cooling gas C .

[0087] The arithmetic mean roughness Ra of the inner peripheral surface 40b of the insulator 40 is preferably 2 times or more the arithmetic mean roughness Ra of the inner peripheral surface 31a of the first through-hole 31. In this case, the cooling gas C can be sufficiently cooled by the inner peripheral surface 40b of the insulator 40, and the cooling gas introduction hole 30 that is not easily heated by the inner peripheral surface 31a of the first through-hole 31 is formed. And for the same reason, the arithmetic mean roughness Ra of the inner peripheral surface 40b of the insulator 40 is more preferably 3 times or more the arithmetic mean roughness Ra of the inner peripheral surface 31a of the first through-hole 31. For example, it may also be 2 times or more, but is not limited to these examples. Further, in order to obtain the above-described various effects, it is further preferred that the arithmetic mean roughness Ra of the inner peripheral surface 40b of the insulator 40 is 1.5 μm or more, and the arithmetic mean roughness Ra of the inner peripheral surface 31a of the first through-hole 31 is 0.5 μm or less.

[0088] The first through-hole 31 of the present embodiment is mainly formed by machining. In order to improve the surface properties of the inner peripheral surface 31a of the first through-hole 31, it is preferable to perform dense finishing when forming the first through-hole 31. Further, after forming the first through-hole 31, the surface properties of the inner peripheral surface 31a can also be improved by performing brush grinding or polishing.

[0089] (Curved surface)

[0090] As Figure 2 shown, the base portion 3 has a curved surface 3f at the opening of the second through-hole 32. The curved surface 3f is connected to the opposed surface 3a (upper surface (flat portion)). The curved surface 3f extends along the circumferential direction around the central axis J with the same cross-sectional shape. Regarding the curved surface 3f, as described below, an example is a smooth surface that has no depression when viewed from a cross-section passing through the central axis J. The hole formed by the curved surface 3f is preferably circular in plan view and continuously increases toward the upper side.

[0091] Hereinafter, in the description of the curved surface 3f, the radial direction centered on the central axis J may sometimes be simply referred to as the "radial direction", and the circumferential direction with respect to the central axis J may be simply referred to as the "circumferential direction".

[0092] The curved surface 3f of the present embodiment connects the opposed surface 3a and the inner peripheral surface 32a of the second through-hole 32 with the same radius of curvature. The curved surface 3f is smoothly connected to the opposed surface 3a at the upper end portion and is smoothly connected to the inner peripheral surface 32a at the lower end portion.

[0093] The outer peripheral surface 40c of the insulator 40 faces the radially inner side of the curved surface 3f. A part of the first bonding portion 4a of the bonding layer 4 enters between the curved surface 3f and the inner peripheral surface 40b of the insulator 40. Thus, the curved surface 3f is covered by the first bonding portion 4a. Also, the portion of the outer peripheral surface 40c of the insulator 40 that faces the curved surface 3f in the radial direction is also covered by the first bonding portion 4a.

[0094] The base portion 3 and the bonding layer 4 are made of materials having different coefficients of thermal expansion. More specifically, the base portion 3 is made of a metal material with high thermal conductivity, and the bonding layer 4 is made of resin. Therefore, as the temperature changes, thermal stress is imparted to the interface between the bonding layer 4 and the base portion 3, and the bonding layer 4 may peel off from the interface. When the bonding layer peels off, a part of the metal substrate is exposed in the He gas flow path, and this may become the starting / ending point of discharge. In particular, the corners of the metal (such as ordinary corners) are likely to concentrate the electric field and are more likely to become the starting / ending point of discharge. Also, thermal stress is likely to concentrate at the corners provided on the base portion 3, so peeling is most likely to occur starting from the corners of the base portion 3. Such corners have points (vertices) where two straight lines (surfaces) are in contact when observed in cross section.

[0095] On the other hand, according to the present embodiment, in the opposed surface 3a of the base portion 3 that contacts the bonding layer 4, the corners of the opening edge of the second through hole 32 are rounded to form a curved surface 3f. That is, the aforementioned corners have a convex or substantially convex curve when observed in cross section. Thus, corners that are likely to become the starting point of peeling are not formed at the interface where the bonding layer 4 is bonded to the base portion 3, and thus peeling of the bonding layer 4 relative to the base portion 3 can be suppressed.

[0096] If peeling occurs at the interface between the base portion 3 and the bonding layer 4, discharge may occur from the base portion 3. Also, since charges are likely to concentrate at the corners, when the peeled portion in the base portion 3 is a corner, discharge is more likely to occur. According to the present embodiment, by forming the corners of the base portion 3 as the curved surface 3f, discharge from the base portion 3 can be suppressed. Generally, it is known that if the diameter of the second through hole 32 that constitutes the cooling gas introduction hole 30 is increased, discharge from the base portion 3 is likely to occur. In the present embodiment, since a structure that can suppress discharge from the base portion 3 is adopted, the diameter of the second through hole 32 can be increased. That is, according to the present embodiment, a structure that increases the diameter of the second through hole 32, increases the volume of the interior V2 of the insulator 40, and sufficiently cools the cooling gas C inside the cooling gas introduction hole 30 can be adopted, and as a result, the cooling efficiency of the plate-like specimen W using the cooling gas C can be improved.

[0097] In the present embodiment, the case where the entire surface of the curved surface 3f is covered with the first bonding portion 4a has been described. For example, an example in which the first bonding portion 4a fills the space between the curved surface 3f and the lower surface 2b of the electrostatic chuck portion 2 has been described. Further, when the base portion 3 and the electrostatic chuck portion 2 are bonded via the bonding layer 4, the first bonding portion 4a enters the gap between the curved surface 3f and the outer peripheral surface 40c of the insulator 40. Therefore, the first bonding portion 4a cannot cover the entire curved surface 3f, and there may be a case where only a part of the curved surface 3f, for example, the upper region of the curved surface 3f, is covered with the first bonding portion 4a. However, even in this case, as long as the first bonding portion 4a covers at least the boundary portion between the opposed surface 3a and the curved surface 3f, it is possible to obtain an effect of suppressing the peeling of the bonding layer 4 from the base portion 3 from the boundary portion to a certain extent or more.

[0098] In the present embodiment, the radius of curvature R of the curved surface 3f on the cross section along the central axis J (the cross section including the central axis J) is preferably larger than the thickness dimension d1 of the internal electrode 13 for electrostatic adsorption. Thereby, the radius of curvature R of the curved surface 3f can be set to a sufficient size for suppressing the peeling of the bonding layer 4. Further, the radius of curvature can be obtained, for example, by observing the cross section including the central axis J of the base portion 3 and from a photographed image or the like.

[0099] In the present embodiment, the radius of curvature R of the curved surface 3f on the cross section along the central axis J is preferably larger than the thickness dimension t1 of the first bonding portion 4a. Thereby, the radius of curvature R of the curved surface 3f can be set to a sufficient size for suppressing the peeling of the bonding layer 4. Further, by setting the radius of curvature R within such a range, when the base portion 3 and the electrostatic chuck portion 2 are bonded, the adhesive constituting the bonding layer 4 smoothly expands from the opposed surface 3a (the upper surface (flat portion)) to the curved surface 3f while forming the first bonding portion 4a. Therefore, the first bonding portion 4a can uniformly cover the boundary portion between the opposed surface 3a and the curved surface 3f, the concentration of stress at the corner can be further reduced, and bubbles are not easily generated at the interface between the bonding layer 4 and the base portion 3, and the first bonding portion 4a can be formed uniformly.

[0100] Regarding the radius of curvature R of the curved surface 3f on the cross-section along the central axis J, in order to disperse the electric field concentrated in this part, it is preferably larger than the thickness dimension d1 of the internal electrode 13 for electrostatic adsorption. Specifically, it is preferably 10 μm or more. By setting the radius of curvature R of the curved surface 3f to 10 μm or more, the stress caused by thermal stress is not easily concentrated on the curved surface 3f, the peeling of the adhesive layer 4 on the curved surface 3f can be suppressed, and the concentrated electric field can be dispersed, and the flying / adsorbing foreign charged particles, etc. can be dispersed. Also, in order to stabilize the adhesive layer with the thickness dimension t1 and make it continuous with the curved surface 3f, the radius of curvature R of the curved surface 3f is preferably larger than t1. Specifically, for example, it is more preferably 100 μm or more, and further preferably 1000 μm or more. When the radius of curvature R is set to 100 μm or more or 1000 μm or more, the peeling of the adhesive layer 4 on the curved surface 3f can be more reliably suppressed. In addition, the curved surface 3f can be easily and stably formed.

[0101] In addition, in the present embodiment, the case where the radius of curvature R of the curved surface 3f is constant over the entire curved surface 3f has been described. However, the radius of curvature R of the curved surface 3f may also continuously change along the radial direction of the central axis J. That is, the curved surface 3f may also be composed of a complex surface such as an elliptical surface or a free surface. Even in this case, the minimum radius of curvature R among the radii of curvature R of each part of the curved surface 3f only needs to be within the above range.

[0102] The curved surface 3f can be formed by polishing and grinding the corners of the opening edge of the second through hole 32 after forming the second through hole 32 using a drilling machine or the like. Also, a special cutting tool that reprocesses the opening edge of the second through hole 32 into a curved shape can be used to form the curved surface 3f.

[0103] (Deformation example of the curved surface)

[0104] In the above embodiment, the case where the curved surface 3f is directly connected to the opposing surface 3a and the inner peripheral surface 32a of the second through hole 32 has been described. However, as long as the curved surface is connected to the opposing surface 3a, it may not be connected to the inner peripheral surface 32a of the second through hole 32. Also, the number of curved surfaces is not limited to 1, and for example, it may be 2.

[0105] Figure 3 It is a schematic cross-sectional view showing the curved surface 3Af which is a deformation example that can be adopted in the first embodiment. In addition, the same reference numerals are given to the constituent elements in the same manner as in the above embodiment, and their descriptions are omitted. Also, the curved surface 3Af of this deformation example can be adopted not only in the first embodiment but also in all the embodiments described below.

[0106] A chamfered portion 3Ac is provided between the opposed surface 3a of the base portion 3A in this modification example and the first through hole 31. The chamfered portion 3Ac extends in the circumferential direction around the central axis J with the same cross-sectional shape. The chamfered portion 3Ac is located at the upper opening of the second through hole 32, and the diameter of the second through hole 32 increases as it goes upward. The chamfered portion 3Ac may have a smooth surface without protrusions or depressions.

[0107] The curved surface 3Af of this modification example is provided at the boundary portion between the opposed surface 3a and the chamfered portion 3Ac. The curved surface 3Af is connected to the opposed surface 3a and the chamfered portion 3Ac. Even when the curved surface 3Af has such a structure, the curved surface 3Af can suppress the formation of a corner portion at the interface between the first bonding portion 4a and the opposed surface 3a, and can suppress the peeling of the first bonding portion 4a from the opposed surface 3a.

[0108] In addition, in Figure 3 the modification example shown, a corner portion is formed at the boundary portion 3Ag between the chamfered portion 3Ac and the inner peripheral surface 32a of the second through hole 32. For this boundary portion 3Ag, it may also be set as a curved surface the same as the boundary portion of the opposed surface 3a.

[0109] [Semiconductor manufacturing apparatus]

[0110] Figure 4 It is an explanatory diagram of a semiconductor manufacturing apparatus 1000 having the above-described electrostatic chuck device 1. The semiconductor manufacturing apparatus 1000 includes an electrostatic chuck device 1, a vacuum chamber 200, an upper electrode 300, a magnet 400, a gas supply mechanism 500, a vacuum pump 600, and a plasma stabilization system 700.

[0111] The vacuum chamber 200 is used as a reaction field for accommodating the electrostatic chuck device 1 and performing plasma processing therein. The vacuum chamber 200 can adopt a known structure used in semiconductor manufacturing apparatuses. The vacuum chamber 200 has a gate (not shown) for loading and unloading plate-shaped specimens.

[0112] The upper electrode 300 is a counter electrode that is accommodated in the vacuum chamber 200 and is used in cooperation with the electrostatic chuck device 1 when generating plasma in the vacuum chamber 200. The upper electrode 300 is connected to a power supply (not shown).

[0113] The magnet 400 is disposed around the vacuum chamber 200 and generates a longitudinal magnetic field in the space between the upper electrode 300 and the electrostatic chuck device 1 in the vacuum chamber 200.

[0114] The gas supply mechanism 500 supplies a plasma gas G into the vacuum chamber 200. The gas supply mechanism 500 supplies the plasma gas G into the vacuum chamber 200, for example, from a gas hole provided in the upper electrode 300.

[0115] The vacuum pump 600 discharges the gas in the vacuum chamber 200 and adjusts the atmosphere for generating the plasma. The vacuum pump 600 is connected, for example, to a position lower than the electrostatic chuck device 1 in the vacuum chamber 200.

[0116] The plasma stabilization system 700 detects and compensates for various external factors that change the state of the plasma generated in the semiconductor manufacturing apparatus 1000, thereby stabilizing the state of the plasma. The plasma stabilization system 700 includes a detector 710 and a control unit 720 that controls the semiconductor manufacturing apparatus 1000 based on the detection results detected by the detector 710.

[0117] The detector 710 directly or indirectly detects the state of the plasma in the vacuum chamber 200. The detector 710 may be one or more. Examples of the items detected by the detector 710 include, for example, the degree of vacuum in the vacuum chamber 200, the color of the plasma, the temperature of the plasma, the capacitance between the upper electrode 300 and the internal electrode for plasma generation (not shown) provided in the electrostatic chuck device 1, and the inductance between the upper electrode 300 and the internal electrode for plasma generation.

[0118] The control unit 720 controls the semiconductor manufacturing apparatus 1000 based on the detection values of the respective items detected by the detector 710 or the change amount per unit time of the detection values. The control unit 720 pre-stores the correspondence relationship between the detection values of the above items and the state of the plasma generated in the vacuum chamber 200. The control unit 720 performs feedback control on the semiconductor manufacturing apparatus 1000 based on the detection values and the above correspondence relationship so that the state of the plasma falls within a preset range. Examples of the items for feedback control include the temperature, the degree of vacuum, and the bias voltage in the semiconductor manufacturing apparatus.

[0119] Thereby, the plasma stabilization system 700 can suppress long-term changes in the plasma state in the semiconductor manufacturing apparatus 1000, thereby stabilizing the state.

[0120] Such a plasma stabilization system is effective in suppressing long-term changes in the plasma state of the entire manufacturing process using the semiconductor manufacturing apparatus. On the other hand, the plasma stabilization system has no effect of suppressing state changes for change factors that occur in an extremely short time, such as abnormal discharges in the wafer process.

[0121] On the other hand, since the semiconductor manufacturing apparatus 1000 includes the above-described electrostatic chuck device 1, abnormal discharges that occur in the wafer process can be suppressed. Therefore, the semiconductor manufacturing apparatus 1000 can stabilize the plasma both in the long term and in the short term by including the plasma stabilization system 700.

[0122] In addition, the control unit 720 may be an inherent structure of the plasma stabilization system 700, and a control device that controls the semiconductor manufacturing apparatus 1000 may also have this function.

[0123] In such a semiconductor manufacturing apparatus 1000, for example, depending on the position of the exhaust port of the vacuum chamber 200 (the connection position of the vacuum pump 600), the tendency of the attachment of charged foreign particles on the side circumferential surface of the electrostatic chuck unit 2 may be different. In the case where the above tendency has been empirically determined for the semiconductor manufacturing apparatus 1000, the electrostatic chuck unit 2 may adopt the following structure: by making the arithmetic mean roughness Ra of the side circumferential surface at the position where charged foreign particles are likely to attach smaller than that of other side circumferential surfaces, etc., the attachment of charged foreign particles is suppressed.

[0124] According to the semiconductor manufacturing apparatus 1000 of the present embodiment, since it has the above-described electrostatic chuck device 1, it is possible to suppress the occurrence of dielectric breakdown (discharge).

[0125] Moreover, the semiconductor manufacturing apparatus 1000 can suppress abnormal discharge (short-term variation of plasma) through the electrostatic chuck device 1, and can suppress long-term variation of plasma through the plasma stabilization system 700. Therefore, not only can stable plasma processing be performed, but also a semiconductor manufacturing apparatus with improved yield can be provided.

[0126] <Second Embodiment>

[0127] Figure 5 It is an enlarged cross-sectional view of the electrostatic chuck device 101 of the second embodiment. The main difference between the electrostatic chuck device 101 of the second embodiment and the first embodiment is that an insulator curved surface 140f is provided at the upper end portion of the insulator 140.

[0128] In addition, the same reference numerals are assigned to the constituent elements in the same manner as in the above-described embodiment, and the description thereof is omitted.

[0129] The electrostatic chuck device 101 includes an electrostatic chuck portion 2, a base portion 3, an adhesive layer 4, and an insulator 140. Moreover, in the electrostatic chuck device 101, a plurality of cooling gas introduction holes 30 that penetrate these vertically are provided in the electrostatic chuck portion 2, the base portion 3, and the adhesive layer 4. The cooling gas introduction hole 30 has a first through hole 31 that is a part penetrating the electrostatic chuck portion 2 and a second through hole 32 that is a part penetrating the base portion 3. A curved surface 3f that is located at the opening of the second through hole 32 and is connected to the opposed surface 3a is provided in the base portion 3.

[0130] Similar to the first embodiment, a cylindrical insulator 140 is disposed in the second through hole 32. The insulator 140 extends along the thickness direction Z (i.e., the vertical direction). The upper end of the insulator 140 lies on the same plane as the opposing surface 3a of the base portion 3.

[0131] In the insulator 140 of the present embodiment, an insulator curved surface 140f is provided at the boundary portion between the upper end surface 140a and the outer peripheral surface 140c. The insulator curved surface 140f connects the upper end surface 140a and the outer peripheral surface 140c with the same radius of curvature. The insulator curved surface 140f is smoothly connected to the upper end surface 140a at the upper end portion and is smoothly connected to the outer peripheral surface 140c at the lower end portion. The outer diameter of the insulator 140 at the insulator curved surface 140f preferably decreases as it approaches the support plate 12.

[0132] According to the present embodiment, it is possible to suppress the formation of corners of the insulator 140 at the interface between the insulator 140 and the adhesive layer 4. Therefore, even if thermal stress is applied to the interface between the insulator 140 and the adhesive layer 4, the adhesive layer 4 is not easily peeled off from the insulator 140. And, according to the present embodiment, by providing the curved surface 3f on the insulator 140, a wider gap is ensured between the curved surface 3f of the base portion 3 and the insulator curved surface 140f of the insulator 140, so that the adhesive constituting the adhesive layer 4 can be sufficiently filled in this gap. Thereby, the first adhesive portion 4a of the adhesive layer 4 can cover the curved surface 3f of the base portion 3 in a wider range, and it is possible to more effectively suppress the peeling of the adhesive layer 4 from the base portion 3.

[0133] In the present embodiment, with respect to the insulator curved surface 140f, the radius of curvature of the insulator curved surface 140f in the cross section along the central axis J is the same as the radius of curvature of the curved surface 3f. However, the radius of curvature of the insulator curved surface 140f and the radius of curvature of the curved surface 3f do not necessarily have to be the same. The radius of curvature of the insulator curved surface 140f is preferably set to the same numerical range as the radius of curvature of the curved surface 3f. That is, the radius of curvature of the insulator curved surface 140f is preferably larger than the thickness dimension d1 of the electrostatic adsorption internal electrode 13. And, the radius of curvature of the insulator curved surface 140f is preferably larger than the thickness dimension t1 of the first adhesive portion 4a. More specifically, the radius of curvature of the insulator curved surface 140f is preferably 10 μm or more, more preferably 100 μm or more, and further preferably 1000 μm or more. Thereby, it is possible to suppress the mixing of air bubbles into the adhesive layer 4 during assembly while suppressing the peeling of the adhesive layer 4 on the insulator curved surface 140f.

[0134] <Third Embodiment>

[0135] Figure 6FIG. 0 is an enlarged cross-sectional view of the electrostatic chuck device 201 according to the third embodiment. The main difference between the electrostatic chuck device 201 according to the third embodiment and the first embodiment is that a third bonding portion 204c of the bonding layer 204 is provided between the outer peripheral surface 40c of the insulator 40 and the inner peripheral surface 32a of the second through-hole 32. In addition, the same reference numerals are given to the components having the same configuration as in the above-described embodiments, and the description thereof is omitted.

[0136] The electrostatic chuck device 201 includes an electrostatic chuck portion 2, a base portion 3, a bonding layer 204, and an insulator 40. In the electrostatic chuck device 201, a plurality of cooling gas introduction holes 30 that penetrate these components vertically are provided in the electrostatic chuck portion 2, the base portion 3, and the bonding layer 204. The cooling gas introduction hole 30 has a first through-hole 31 that is a part penetrating the electrostatic chuck portion 2 and a second through-hole 32 that is a part penetrating the base portion 3. A curved surface 3f that is located at the opening of the second through-hole 32 and is connected to the opposed surface 3a is provided in the base portion 3.

[0137] Similar to the first embodiment, a cylindrical insulator 40 is disposed in the second through-hole 32. The insulator 40 of the present embodiment is adhesively fixed to the inner peripheral surface 32a of the second through-hole 32 by the third bonding portion 204c of the bonding layer 204. That is, the bonding layer 204 of the present embodiment has, in addition to the first bonding portion 4a, the second bonding portion 4b, and the remaining portion 4e, a third bonding portion 204c.

[0138] The third bonding portion 204c is interposed between the inner peripheral surface 32a of the second through-hole 32 and the outer peripheral surface 40c of the insulator 40. The third bonding portion 204c fixes the insulator 40 to the inner peripheral surface 32a of the second through-hole 32. The third bonding portion 204c may be formed of the same type of adhesive as the first bonding portion 4a and the second bonding portion 4b, or may be formed of a different type of adhesive.

[0139] The third bonding portion 204c covers the inner peripheral surface 32a of the second through-hole 32. Therefore, the bonding layer 204 can continuously cover the opposed surface 3a, the curved surface 3f, and the inner peripheral surface 32a of the base portion 3 without interruption. According to the present embodiment, the starting point of peeling is not easily generated at the interface between the bonding layer 204 and the base portion 3, and peeling of the bonding layer 204 can be suppressed. In particular, in the present embodiment, since the bonding layer 204 covers the entire curved surface 3f, even if a thermal stress is applied to the interface between the base portion 3 and the bonding layer 204, peeling of the bonding layer 204 on the curved surface 3f can be effectively suppressed.

[0140] In addition, the third bonding portion 204c described in the present embodiment is not limited to the present embodiment, and may be provided on each bonding layer in other embodiments.

[0141] <Fourth Embodiment>

[0142] Figure 7 FIG. 308 is an enlarged cross-sectional view of the electrostatic chuck device 301 according to the fourth embodiment. The main difference between the electrostatic chuck device 301 of the fourth embodiment and the first embodiment lies in the position of the upper end portion of the insulator 340. In addition, the same reference numerals are given to the constituent elements in the same manner as in the above embodiments, and the description thereof is omitted.

[0143] The electrostatic chuck device 301 includes an electrostatic chuck portion 2, a base portion 3, an adhesive layer 304, and an insulator 340. And, in the electrostatic chuck device 301, a plurality of cooling gas introduction holes 30 penetrating these vertically are provided in the electrostatic chuck portion 2, the base portion 3, and the adhesive layer 304. The cooling gas introduction hole 30 has a first through hole 31 as a portion penetrating the electrostatic chuck portion 2 and a second through hole 32 as a portion penetrating the base portion 3. A curved surface 3f is provided in the base portion 3 at the opening of the second through hole 32 and connected to the opposed surface 3a.

[0144] Similar to the first embodiment, a cylindrical insulator 340 is disposed in the second through hole 32. The upper end surface 340a of the insulator 340 of the present embodiment is located at a position lower than the opposed surface 3a of the base portion 3. The upper end surface 340a of the insulator 340 is located at a position lower than the lower end portion 3b in the thickness direction Z of the curved surface 3f.

[0145] Similar to the first embodiment, the adhesive layer 304 has a second adhesive portion 304b located between the upper end surface 340a of the insulator 340 and the electrostatic chuck portion 2. The second adhesive portion 304b of the present embodiment covers the entire curved surface 3f. Therefore, even if thermal stress is applied to the interface between the base portion 3 and the adhesive layer 304, peeling of the adhesive layer 304 on the curved surface 3f can be effectively suppressed.

[0146] When the curved surface 3f has the same radius of curvature R as a whole, when the thickness dimension t2 of the second adhesive portion 304b is larger than the sum of the radius of curvature R of the curved surface 3f and the thickness dimension t1 of the first adhesive portion 4a, the entire curved surface 3f can be sufficiently covered. And if the thickness dimension t2 of the second adhesive portion 304b is twice or more the thickness dimension t1 of the first adhesive portion 4a, the second adhesive portion 304b can cover the curved surface 3f to an extent that can suppress peeling on the curved surface 3f.

[0147] <Fifth Embodiment>

[0148] Figure 8FIG. 0 is an enlarged cross-sectional view of an electrostatic chuck device 401 according to the fifth embodiment. The electrostatic chuck device 401 according to the fifth embodiment is similar to the fourth embodiment. The main difference from the fourth embodiment is that a tapered surface 440t is provided on the inner peripheral surface 440b of the insulator 440. In addition, the same reference numerals are given to the components that are the same as those in the above embodiments, and the description thereof is omitted.

[0149] The electrostatic chuck device 401 includes an electrostatic chuck portion 2, a base portion 3, an adhesive layer 304, and an insulator 440. In the electrostatic chuck device 401, a plurality of cooling gas introduction holes 30 that penetrate these vertically are provided in the electrostatic chuck portion 2, the base portion 3, and the adhesive layer 304. The cooling gas introduction hole 30 has a first through hole 31 that is a portion penetrating the electrostatic chuck portion 2 and a second through hole 32 that is a portion penetrating the base portion 3. A curved surface 3f that is located at the opening of the second through hole 32 and is connected to the opposed surface 3a is provided in the base portion 3.

[0150] Similar to the fourth embodiment, a cylindrical insulator 440 is disposed in the second through hole 32. The upper end surface 440a of the insulator 440 in this embodiment is located at a position lower than the opposed surface 3a of the base portion 3. The upper end surface 440a of the insulator 440 is located at a position lower than the lower end portion 3b in the thickness direction Z of the curved surface 3f. Therefore, the second adhesive portion 304b of the adhesive layer 304 covers the entire curved surface 3f, suppressing peeling of the adhesive layer 304 on the curved surface 3f.

[0151] In this embodiment, a tapered surface 440t that decreases in diameter (inner diameter) as it goes upward is provided on the inner peripheral surface 440b of the insulator 440. The inner diameter on the upper end surface 440a of the insulator 440 is substantially equal to the inner diameter of the first through hole 31. Therefore, the second adhesive portion 304b disposed between the upper end surface 440a of the insulator 440 and the electrostatic chuck portion 2 in the adhesive layer 304 can be thickened in the radial direction of the second through hole 32. That is, the interface between the insulator 440 and the second adhesive portion 304b can be extended in the radial direction, thereby extending the discharge path of the base portion 3, and thus discharge from the base portion 3 can be suppressed.

[0152] In this embodiment, the size d2 of the second adhesive portion 304b in the radial direction of the second through hole 32 is preferably larger than the thickness dimension t1 of the first adhesive portion 4a. In this case, by extending the interface between the insulator 440 and the second adhesive portion 304b, discharge from the base portion 3 can be effectively suppressed.

[0153] The tapered surface 440t of this embodiment is provided in an upper region including the upper end in the total length of the inner peripheral surface 440b of the insulator 440. However, the region where the tapered surface 440t is provided is not limited to this embodiment. For example, asFigure 9 Like the conical surface 440At shown as a modified example, it can also be provided over the entire length of the inner peripheral surface 440Ab of the insulator 440A.

[0154] By providing the conical surface 440t on the inner peripheral surface 440b of the insulator 440 and the conical surface 440At on the inner peripheral surface 440Ab of the insulator 440A, the flow path cross-sectional area of the cooling gas C flowing upward inside the insulators 440 and 440A toward the first through-hole 31 can be gradually reduced. In particular, as shown in the modified example, when the conical surface 440At is provided over the entire length of the insulator 440, the cone angle of the conical surface 440At can be reduced, and the flow path cross-sectional area of the cooling gas C can be reduced more gently. Thereby, the flow path resistance of the cooling gas C is reduced, and the flow velocity of the cooling gas C blown onto the plate-like specimen W can be increased.

[0155] The structure of the cooling gas introduction hole 30 of the present embodiment can also be applied to Figure 1 the pin through-hole 30B shown. In this case, the conical surfaces 440t and 440At function as guides when the lifting pin 22 rises inside the pin through-hole 30B.

[0156] As described above, various embodiments of the present invention have been described, but each structure and their combinations in each embodiment are examples, and additions, omissions, replacements, and other changes can be made without departing from the gist of the present invention. For example, unless otherwise specifically restricted, conditions such as materials, positions, ratios, amounts, types, quantities, dimensions, values, etc. can be changed, added, and omitted as needed. Between the embodiments, the preferred conditions or examples can be replaced or shared with each other. And the present invention is not limited only to the embodiments.

[0157] For example, in the above embodiment, a heating element for heating the electrostatic chuck portion may be embedded in the adhesive layer. And the heating element may also be located inside the electrostatic chuck portion or inside the base portion.

[0158] Moreover, the structure of the cooling gas introduction hole 30 described in the above embodiment can also be applied to the pin through-hole 30B and can also be applied to other through-holes.

[0159] Industrial Applicability

[0160] The present invention provides an electrostatic chuck device with improved cooling efficiency.

[0161] Reference Numeral Explanation

[0162] 1, 101, 201, 301, 401 - Electrostatic chuck device

[0163] 2 - Electrostatic chuck portion

[0164] 2a - Mounting surface

[0165] 2b - Lower surface

[0166] 3, 3A - Base portion

[0167] 3a - Opposing surface

[0168] 3b - End portion

[0169] 3f, 3Af - Bending surface

[0170] 3Ac - Chamfered portion

[0171] 3Ag - Boundary portion

[0172] 4, 204, 304 - Adhesive layer

[0173] 4a - First adhesive portion

[0174] 4b, 304b - Second adhesive portion

[0175] 4e - Remaining portion

[0176] 11 - Mounting plate

[0177] 12 - Support plate

[0178] 13 - Internal electrode for electrostatic adsorption

[0179] 14 - Insulating material layer

[0180] 15 - Power supply terminal

[0181] 16 - Protrusion

[0182] 21 - Flow path

[0183] 22 - Lifting pin

[0184] 30 - Cooling gas inlet hole

[0185] 30B - Pin through - hole

[0186] 31 - First through - hole

[0187] 31a, 32a, 40b, 440b, 440Ab - Inner peripheral surface

[0188] 32 - Second through - hole

[0189] 40, 140, 340, 440, 440A - Insulator

[0190] 40a, 140a, 340a, 440a - Upper end surface

[0191] 40c, 140c - Outer peripheral surface

[0192] 140f - Curved surface of insulator

[0193] 200 - Vacuum chamber

[0194] 204c - Third bonding part

[0195] 300 - Upper electrode

[0196] 400 - Magnet

[0197] 440t, 440At - Tapered surface

[0198] 500 - Gas supply part

[0199] 600 - Vacuum pump

[0200] 700 - Plasma stabilization system

[0201] 710 - Detector

[0202] 720 - Control part

[0203] 1000 - Semiconductor manufacturing apparatus

[0204] C - Cooling gas

[0205] d1, t1, t2 - Thickness dimensions

[0206] d2 - Dimension

[0207] G - Plasma gas

[0208] J - Central axis

[0209] R - Radius of curvature

[0210] V1, V2 - Inside

[0211] W - Plate - shaped specimen

[0212] Z - Thickness direction.

Claims

1. An electrostatic chuck device, comprising: A plate-shaped electrostatic chuck portion that supports a plate-shaped specimen on a mounting surface facing one side in the thickness direction and incorporates an internal electrode for electrostatic adsorption; A base portion that supports the electrostatic chuck portion from the other side in the thickness direction and cools the electrostatic chuck portion; An adhesive layer that is located between the electrostatic chuck portion and the base portion and has a first adhesive portion for fixing the electrostatic chuck portion and the base portion; and A cylindrical insulator, A first through-hole extending in the thickness direction is provided in the electrostatic chuck portion, A second through-hole extending in the thickness direction and communicating with the first through-hole is provided in the base portion, The insulator is disposed in the second through-hole, The base portion has an opposing surface that opposes the electrostatic chuck portion, and also has a curved surface located at the opening of the second through-hole and connected to the opposing surface.

2. The electrostatic chuck device according to claim 1, wherein The radius of curvature of the curved surface in a cross-section along the central axis of the second through-hole is greater than the thickness dimension of the internal electrode for electrostatic adsorption.

3. The electrostatic chuck device according to claim 1, wherein The radius of curvature of the curved surface in a cross-section along the central axis of the second through-hole is greater than the thickness dimension of the first adhesive portion.

4. The electrostatic chuck device according to claim 1, wherein The radius of curvature of the curved surface in a cross-section along the central axis of the second through-hole is 10 μm or more.

5. The electrostatic chuck device according to claim 1, wherein The adhesive layer covers the entire curved surface.

6. The electrostatic chuck device according to claim 5, wherein One end surface of the insulator in the thickness direction is located on the other side in the thickness direction, which is more on the other side in the thickness direction than the end of the curved surface and the second through-hole on the other side in the thickness direction, The adhesive layer has a second adhesive portion located between the end surface of the insulator and the electrostatic chuck portion.

7. The electrostatic chuck device according to claim 6, wherein The thickness dimension of the second adhesive portion is 2 times or more the thickness dimension of the first adhesive portion.

8. The electrostatic chuck device according to claim 6, wherein The dimension of the second adhesive portion in the radial direction of the second through-hole is greater than the thickness dimension of the first adhesive portion.

9. The electrostatic chuck device according to claim 5, wherein The adhesive layer has a third adhesive portion, and the third adhesive portion is located between the inner peripheral surface of the second through-hole and the outer peripheral surface of the insulator and fixes the insulator to the inner peripheral surface of the second through-hole.

10. The electrostatic chuck device according to claim 1, wherein The volume inside the insulator is 5 times or more the volume inside the first through-hole.

11. The electrostatic chuck device according to claim 1, wherein The arithmetic mean roughness Ra of the inner peripheral surface of the insulator is greater than the arithmetic mean roughness Ra of the inner peripheral surface of the first through-hole.

12. The electrostatic chuck device according to claim 11, wherein The arithmetic mean roughness Ra of the inner peripheral surface of the insulator is at least twice the arithmetic mean roughness Ra of the inner peripheral surface of the first through hole.

13. The electrostatic chuck device according to claim 11, wherein the arithmetic mean roughness Ra of the inner peripheral surface of the insulator is 1.5 μm or more, and the arithmetic mean roughness Ra of the inner peripheral surface of the first through hole is 0.5 μm or less.

14. The electrostatic chuck device according to claim 1, wherein a tapered surface whose diameter decreases as it approaches one side in the thickness direction is provided on the inner peripheral surface of the insulator.

15. The electrostatic chuck device according to claim 1, wherein a chamfered portion is provided at a boundary portion between the opposed surface and the inner peripheral surface of the second through hole, and the curved surface is connected to the opposed surface and the chamfered portion.

Images