Wafer placement table

Abstract

A wafer placement table 10 comprises: a ceramic plate 20 incorporating an electrostatic electrode 22; a base plate 30 having a refrigerant flow passage 32 therein; a base plate through-hole 34 penetrating through the base plate 30 in a vertical direction and having a small-diameter hole upper portion 34a, a large-diameter hole lower portion 34b, and a hole step portion 34c, the hole lower portion 34b being provided below the refrigerant flow passage 32; an insulating tube 50 accommodated in the hole upper portion 34a; a resin tube 60 accommodated in the hole lower portion 34b, having an upper surface 61 bonded to the hole step portion 34c via an adhesive layer 80, and having a diameter larger than that of the insulating tube 50; and a power supply member 70 having an upper surface connected to the electrostatic electrode 22 and inserted into the insulating tube 50 and the resin tube 60. A protruding ring 62 for securing a gap G is provided on the upper surface 61 of the resin tube 60, and the gap G is filled with the adhesive layer 80.

Description

Wafer mounting table

[0001] The present invention relates to a wafer mounting table.

[0002] Conventionally, a wafer mounting table including an insulating ceramic plate having built-in electrodes and a conductive cooling plate having a refrigerant flow path inside has been known. For example, the wafer mounting table described in Patent Document 1 has a stepped hole penetrating the cooling plate in the vertical direction. The stepped hole has a small-diameter upper hole, a large-diameter lower hole, and a hole step portion between the upper hole and the lower hole. An insulating tube made of ceramic is inserted into the upper hole of the stepped hole. A resin tube (fixing plate) having a larger diameter than the insulating tube is disposed in the lower hole of the stepped hole. The lower surface of the insulating tube is inserted into the upper surface of the resin tube. A power supply member is inserted into the insulating tube and the resin tube. The upper surface of the power supply member is connected to the electrode. In Patent Document 1, it is exemplified that the resin tube and the cooling plate are fixed by screwing.

[0003] Japanese Unexamined Patent Application Publication No. 2015-207765

[0004] By the way, in Patent Document 1, it is also conceivable to fix the upper surface of the resin tube and the hole step portion of the cooling plate with an adhesive layer. (Such a configuration is not described in Patent Document 1). However, in that case, if the thickness of the adhesive layer is thin (for example, 20 to 30 μm), the shear strain due to the thermal expansion difference between the resin tube and the cooling plate during use of the wafer mounting table is large, and the fixing plate may be peeled off.

[0005] The present invention has been made to solve such problems, and the main object is to prevent the resin tube fixed to the base plate via the adhesive layer from peeling off.

[0006] [1] The wafer mounting stand of the present invention comprises: a ceramic plate having a wafer mounting surface on its upper surface and containing electrodes; a base plate provided on the lower side of the ceramic plate and having a refrigerant flow path inside; a stepped hole penetrating the base plate in the vertical direction and having a small diameter upper hole, a large diameter lower hole, and a hole step between the upper and lower holes, with the lower hole being located below the refrigerant flow path; an insulating tube inserted into the upper hole; a resin tube inserted into the lower hole, with its upper surface bonded to the hole step via an adhesive layer and having a larger diameter than the insulating tube; and a power supply member whose upper surface is connected to the electrodes and inserted into the insulating tube and the resin tube, wherein a convex member is provided on the upper surface of the resin tube to secure a gap between the upper surface of the resin tube and the hole step of the stepped hole, and the adhesive layer is filled into the gap.

[0007] In this wafer mounting stand, power supply components are inserted into insulating tubes and resin tubes provided in stepped holes in the base plate. The insulating tubes are inserted into the upper part of the stepped holes. The resin tubes, which have a larger diameter than the insulating tubes, are inserted into the lower part of the stepped holes, and their upper surfaces are bonded to the stepped portion of the holes via an adhesive layer. The upper surface of the resin tubes is provided with a convex member to ensure a gap between the upper surface of the resin tubes and the stepped portion of the holes, and the adhesive layer is filled into this gap. Therefore, in this wafer mounting stand, the adhesive layer can be made thicker compared to when the upper surface of the resin tubes is flat, and the shear strain of the adhesive layer can be reduced. As a result, in environments where high and low temperatures are repeatedly observed, the adhesive layer becomes less likely to break and the resin tubes become less likely to peel off.

[0008] [2] In the wafer mounting stage of the present invention (the wafer mounting stage described in [1] above), the convex member may be a ring member. In this case, the convex member can be formed relatively easily.

[0009] [3] In the wafer mounting stand of the present invention (the wafer mounting stand described in [1] above), the convex member may be composed of a plurality of small protrusions of the same height. This makes it easier to increase the contact area between the stepped portion of the stepped hole in the base plate and the upper surface of the resin tube.

[0010] [4] In the wafer mounting stand of the present invention (the wafer mounting stand described in any of [1] to [3] above), the convex member may be provided so as to be in contact with the outer edge of the upper surface of the resin tube. This makes it easier to hold the upper surface of the resin tube and the hole step portion parallel to each other compared to the case where the convex member is provided along the opening edge of the hole in the resin tube.

[0011] [5] In the wafer mounting stage of the present invention (the wafer mounting stage described in any of [1] to [4] above), the height of the convex member may be 50 μm or more and 300 μm or less. This makes it possible to make the adhesive layer sufficiently thicker compared to the case where the upper surface of the resin tube is flat.

[0012] [6] In the wafer mounting stage of the present invention (the wafer mounting stage described in any of [1] to [5] above), the resin tube may be made of engineering plastic. Engineering plastics are suitable as a material for resin tubes because they have high heat resistance and are generally cheaper than ceramics.

[0013] [7] In the wafer mounting stand of the present invention (the wafer mounting stand described in any of [1] to [6] above), the lower end of the insulating tube may be fitted into a stepped groove provided on the upper surface of the resin tube. This further improves the insulation between the power supply member and the base plate.

[0014] [8] In the wafer mounting stage of the present invention (the wafer mounting stage described in any of [1] to [7] above), the base plate may have an average coefficient of linear expansion of 10 ppm / K or less at 40 to 570°C. This increases the difference in linear expansion between the base plate and the resin tube, thus increasing the effect obtained when the present invention is applied.

[0015] [9] In the wafer mounting stage of the present invention (the wafer mounting stage described in any of [1] to [8] above), the material of the base plate may be a composite material of metal and ceramic. Since composite materials of metal and ceramic are generally difficult to process, there is great value in fixing the resin tube with adhesive rather than with screws.

[0016] Plan view of the wafer mounting stage 10. Cross-sectional view A-A in Figure 1. Enlarged section of Figure 2. Plan view of the resin tube 60. Cross-sectional view B-B in Figure 4A. Graph showing the relationship between shear strain and shear strength of the adhesive layer 80 after heat treatment. Cross-sectional view of a partial embodiment using the resin tube 160. Plan view of the resin tube 160. Cross-sectional view C-C in Figure 7A. Cross-sectional view of a partial embodiment using the resin tube 260. Plan view of the resin tube 260. Cross-sectional view D-D in Figure 9A. Cross-sectional view of another embodiment. Cross-sectional view of another embodiment.

[0017] Preferred embodiments of the present invention will be described with reference to the drawings. Figure 1 is a plan view of the wafer mounting stage 10, Figure 2 is a cross-sectional view taken along line A-A in Figure 1, Figure 3 is a partially enlarged view of Figure 2 (enlarged view within the frame indicated by the dashed line), and Figure 4 is an explanatory diagram of the resin tube 60.

[0018] As shown in Figure 2, the wafer mounting stage 10 includes a ceramic plate 20, a base plate 30, a bonding layer 40, a base plate through hole 34, an insulating tube 50, a resin tube 60, and a power supply member 70.

[0019] The ceramic plate 20 is a ceramic disc (for example, 300 mm in diameter and 5 mm thick) made of an alumina sintered body or an aluminum nitride sintered body. The upper surface of the ceramic plate 20 is a wafer mounting surface 21 on which the wafer W is placed. The ceramic plate 20 incorporates electrostatic electrodes 22. On the wafer mounting surface 21 of the ceramic plate 20, although not shown in the figure, an annular sealing band is formed along the outer edge, and a plurality of small circular protrusions are formed on the entire inner surface of the sealing band. The electrostatic electrodes 22 are planar mesh electrodes and are connected to an external DC power supply (not shown) via a power supply member 70. When a DC voltage is applied to the electrostatic electrodes 22, the wafer W is attracted and fixed to the wafer mounting surface 21 by electrostatic attraction force, and when the application of the DC voltage is removed, the attraction and fixation of the wafer W to the wafer mounting surface 21 is released.

[0020] The base plate 30 is a disc with good electrical and thermal conductivity (for example, a disc with the same or larger diameter as the ceramic plate 20 and a thickness of 25 mm). A refrigerant flow path 32 is formed inside the base plate 30 through which the refrigerant circulates. The refrigerant flowing through the refrigerant flow path 32 is preferably a liquid and preferably electrically insulating. Examples of electrically insulating liquids include fluorine-based inert liquids. As shown in Figure 1, the refrigerant flow path 32 is formed in a spiral shape in a single continuous line across the entire base plate 30 in a plan view, from one end (inlet 32in) to the other end (outlet 32out). The inlet 32in and outlet 32out of the refrigerant flow path 32 are connected to a supply port and a recovery port of an external refrigerant device (not shown), respectively. The refrigerant supplied from the supply port of the external refrigerant device to the inlet 32in of the refrigerant flow path 32 passes through the refrigerant flow path 32 and returns to the recovery port of the external refrigerant device from the outlet 32out of the refrigerant flow path 32. After temperature adjustment, it is supplied again from the supply port to the inlet 32in of the refrigerant flow path 32. The base plate 30 is connected to a high-frequency (RF) power supply and is also used as an RF electrode.

[0021] The material of the base plate 30 can be, for example, a metal or a composite material of metal and ceramic. Examples of metal materials include Al, Ti, Mo, or alloys thereof. Examples of composite materials of metal and ceramic include metal matrix composites (MMC) and ceramic matrix composites (CMC). Specific examples of such composite materials include materials containing Si, SiC, and Ti (also called SiSiCTi), materials in which Al and / or Si are impregnated into a porous SiC body (also called AlSiC), and composite materials of Al2O3 and TiC. It is preferable to select a material for the base plate 30 that has a coefficient of thermal expansion similar to that of the ceramic plate 20. For example, if the material of the ceramic plate 20 is alumina, the material of the base plate 30 may be a material with a thermal expansion coefficient of 4.4 to 14.2 ppm / K (e.g., antimony, gold, tungsten, titanium, pure iron, cast iron, carbon steel, chromium steel, chromium-nickel steel, nickel-chromium alloy, nickel, Monel metal, platinum, platinum-iridium, molybdenum, thorium, zirconium, carbon, beryllium, niobium, chromium, cobalt, iridium, palladium, etc.). Of these, titanium, SiSiCTi, or AlSiC are preferred as the material for the base plate 30 from the viewpoint of the difference in thermal expansion coefficient with the ceramic plate 20 and the productivity of the base plate 30.

[0022] The bonding layer 40 is a metal layer that joins the lower surface of the ceramic plate 20 to the upper surface of the base plate 30. The metal layer can be formed by a well-known thermal compression bonding (TCB) using a metal bonding material (e.g., an Al-Mg-based bonding material or an Al-Si-Mg-based bonding material).

[0023] The base plate through-hole 34 is a circular cross-section hole that penetrates the base plate 30 vertically, and is provided so as not to penetrate the refrigerant flow path 32. The base plate through-hole 34 is a stepped hole, and as shown in Figure 3, it has a small diameter upper part 34a, a large diameter lower part 34b, and a stepped portion 34c between the upper part 34a and the lower part 34b. The upper part 34a penetrates the refrigerant flow path 32 formation region 32a of the base plate 30 (the wall portion of the base plate 30 that separates the refrigerant flow paths 32 from each other) vertically. The upper part 34a communicates with a bonding layer through-hole 44 that penetrates the bonding layer 40 vertically. The lower part 34b is formed below the refrigerant flow path 32 and is larger in diameter than the upper part 34a. Therefore, the diameter of the lower part 34b can be sufficiently large regardless of the shape of the refrigerant flow path 32. The lower part 34b is formed so as to reach the lower surface of the base plate 30 from the outer circumference of the stepped portion 34c. The length of the upper part 34a of the hole is longer than the length of the lower part 34b of the hole.

[0024] The insulating tube 50 is housed in the upper part 34a of the through-hole 34 in the base plate and in the through-hole 44 of the bonding layer. The insulating tube 50 is electrically insulating and is a straight-shaped member made of ceramic such as alumina. The insulating tube 50 has an insulating tube through-hole 54 that extends along the central axis of the insulating tube 50. The insulating tube 50 is fixed to the inner circumferential surface of the upper part 34a of the through-hole 34 in the base plate via an adhesive layer (not shown). The lower end 50a of the insulating tube 50 fits into a stepped groove 63 provided on the upper surface 61 of the resin tube 60.

[0025] The resin pipe 60 is housed in the lower part 34b of the hole 34 through the base plate. The resin pipe 60 is a straight-shaped member made of an electrically insulating resin. Examples of materials for the resin pipe 60 include heat-resistant resins. Examples of such resins include engineering plastics (including super engineering plastics), specifically PEEK (polyether ether ketone), PPA (aromatic polyamide), PPS (polyphenylene sulfide), PSU (polysulfone), PES (polyethersulfone), PEI (polyetherimide), and PAI (polyamideimide). Among these, PEEK is preferred from the viewpoint of heat resistance and the difference in thermal expansion coefficient with respect to the base plate 30. The thermal expansion coefficient of the resin is not particularly limited, but is preferably 30 ppm / K or more and 200 ppm / K or less. The difference in thermal expansion coefficient with respect to the base plate 30 is not particularly limited, but is preferably 25 ppm / K or more and 185 ppm / K or less.

[0026] The resin pipe 60 has a resin pipe through-hole 64 that extends along the central axis of the resin pipe 60. The resin pipe through-hole 64 communicates with the insulating pipe through-hole 54. The outer diameter of the resin pipe 60 is larger than the outer diameter of the insulating pipe 50. That is, the resin pipe 60 has a larger diameter than the insulating pipe 50. This increases the creepage distance (insulation distance) between the outer surface of the power supply member 70 and the inner surface of the lower part 34b of the base plate through-hole 34. The outer diameter of the resin pipe 60 is preferably, for example, 15 mm or more and 50 mm or less. A convex ring 62 is provided on the upper surface 61 of the resin pipe 60, which is concentric with the resin pipe 60. The convex ring 62 is a member that secures a gap G between the upper surface 61 of the resin pipe 60 and the hole step portion 34c of the base plate through-hole 34. The gap G is secured by the upper surface of the convex ring 62 contacting the hole step portion 34c. The gap G is filled with an adhesive layer 80. The adhesive layer 80 is preferably made of an elastic adhesive (for example, silicone or modified silicone). The convex ring 62 is provided so as to be in contact with the outer edge of the upper surface 61 of the resin pipe 60. That is, the outer diameter of the convex ring 62 is the same as the outer diameter of the upper surface 61 of the resin pipe 60. The height of the convex ring 62 is preferably 50 μm or more and 300 μm or less.

[0027] A space S is provided between the outer surface of the resin tube 60 and the inner surface of the lower part 34b of the hole through the base plate 34. When the wafer mounting stand 10 is used in an environment where the temperature fluctuates, a difference in thermal expansion occurs between the resin tube 60 and the base plate 30, and the space S is provided to be wider than this difference in thermal expansion. The adhesive layer 80 may be present in part of the space S. The adhesive layer 80 may also be present between the upper surface of the convex ring 62 and the hole step portion 34c.

[0028] The power supply member 70 is, for example, a metal rod. The metal used for the power supply member 70 is, for example, W, Mo, Ni, and it is preferable that the thermal expansion coefficient of the metal is close to that of the ceramic plate 20. The power supply member 70 is inserted into the resin pipe through hole 64, the insulating pipe through hole 54, and the ceramic plate bottomed hole 24, and is electrically connected to the electrostatic electrode 22 exposed at the bottom of the ceramic plate bottomed hole 24. The ceramic plate bottomed hole 24 is a substantially cylindrical hole provided so as to extend from the lower surface 23 of the ceramic plate 20 to the electrostatic electrode 22. The power supply member 70 is electrically insulated from the base plate 30 by the insulating pipe 50, the resin pipe 60, and the adhesive layer 80. The outer surface of the power supply member 70 may or may not be in contact with the inner surface of the insulating pipe 50 or the inner surface of the resin pipe 60.

[0029] Next, an example of using the wafer mounting stand 10 configured in this way will be described. First, with the wafer mounting stand 10 installed in a chamber (not shown), the wafer W is placed on the wafer mounting surface 21. Then, the pressure inside the chamber is reduced using a vacuum pump to adjust to a predetermined vacuum level, and a DC voltage is applied to the electrostatic electrode 22 of the ceramic plate 20 to generate electrostatic adsorption force, thereby adsorbing and fixing the wafer W to the wafer mounting surface 21. Next, the inside of the chamber is made into a reaction gas atmosphere with a predetermined pressure (for example, several tens to several hundreds of Pa), and in this state, an RF voltage is applied between an upper electrode (not shown) provided on the ceiling of the chamber and the base plate 30 of the wafer mounting stand 10 to generate plasma. The surface of the wafer W is treated by the generated plasma. Coolant is circulated in the coolant channel 32 of the base plate 30 as needed. When the wafer W is treated with plasma in this way, the heat input by the plasma is dissipated by the base plate 30, and the wafer mounting surface 21 is controlled to a desired temperature. In this configuration, the power supply member 70 is electrically insulated from the base plate 30 by the insulating tube 50, the resin tube 60, and the adhesive layer 80. This prevents electrical discharge from occurring between the power supply member 70 and the base plate 30.

[0030] In the wafer mounting table 10 described in detail above, the power supply member 70 is inserted into an insulating tube 50 and a resin tube 60 provided in a through-hole 34 of the base plate (a stepped hole in the base plate 30). The insulating tube 50 is inserted into the upper part 34a of the hole. The resin tube 60, which has a larger diameter than the insulating tube 50, is inserted into the lower part 34b of the hole, and its upper surface 61 is bonded to the stepped portion 34c of the hole via an adhesive layer 80. A convex ring 62 (convex member) is provided on the upper surface 61 of the resin tube 60 to secure a gap G between the upper surface 61 of the resin tube 60 and the stepped portion 34c of the through-hole 34 of the base plate, and the adhesive layer 80 is filled into this gap G. Therefore, in this wafer mounting table 10, the adhesive layer 80 can be made thicker compared to the case where the upper surface 61 of the resin tube 60 is flat, and the shear strain of the adhesive layer 80 can be reduced. As a result, in environments where the temperature fluctuates repeatedly, the adhesive layer 80 becomes less likely to break, and the resin pipe 60 becomes less likely to peel off.

[0031] The shear strain of the adhesive layer 80 is expressed as (difference in thermal expansion ΔL between the base plate 30 and the resin pipe 60) / (thickness t of the adhesive layer 80). For example, Figure 5 shows an example of a graph showing the relationship between the shear strain and shear strength of the adhesive layer 80 after heat treatment. Here, we assume that the difference in thermal expansion ΔL is 100 μm. When the upper surface 61 of the resin pipe 60 is a flat surface (a surface without the convex ring 62), the thickness t of the adhesive layer 80 is approximately 20 to 30 μm. In that case, the shear strain ΔL / t is 3.3 to 5 (see the lightly shaded area in Figure 5), but since the shear strain ΔL / t at the fracture point is approximately 4.5, there is a risk that the adhesive layer 80 will fracture. In contrast, when a convex ring 62 is provided on the upper surface 61 of the resin pipe 60 and the thickness t of the adhesive layer 80 is controlled to 50 to 300 μm, the shear strain ΔL / t becomes 0.3 to 2 (see the darkly shaded area in Figure 5), and since it is far from the fracture point, there is little risk of the adhesive layer 80 rupturing.

[0032] Furthermore, the convex ring 62 can be formed relatively easily on the upper surface 61 of the resin pipe 60 by grinding or the like during the manufacturing process of the resin pipe 60.

[0033] Furthermore, the convex ring 62 is provided so as to be in contact with the outer edge of the upper surface 61 of the resin pipe 60. Therefore, the position of the convex ring 62 when it comes into contact with the hole step portion 34c is more stable compared to when the convex ring is provided along the opening edge of the resin pipe through hole 64. As a result, it is easier to keep the upper surface 61 of the resin pipe 60 and the hole step portion 34c parallel.

[0034] Furthermore, the height of the convex ring 62 is preferably 50 μm or more and 300 μm or less. This allows the adhesive layer 80 to be sufficiently thicker compared to the case where the upper surface 61 of the resin pipe 60 is flat.

[0035] Furthermore, the resin pipe 60 may be made of engineering plastic. Engineering plastics are suitable as a material for the resin pipe 60 because they have high heat resistance and are often cheaper than ceramics.

[0036] Furthermore, the lower end 50a of the insulating pipe 50 fits into a stepped groove 63 provided on the upper surface 61 of the resin pipe 60. As a result, the insulation between the power supply member 70 and the base plate 30 is further enhanced.

[0037] Furthermore, it is preferable that the base plate 30 has an average coefficient of linear expansion of 10 ppm / K or less at 40 to 570°C. This increases the difference in linear expansion between the base plate 30 and the resin tube 60, resulting in greater effects when the present invention is applied. Examples of materials for the base plate 30 that satisfy this condition include titanium, SiSiCTi, or AlSiC.

[0038] The base plate 30 may be made of a composite material of metal and ceramic (as mentioned above). Since composite materials of metal and ceramic are generally difficult to process, there is a significant advantage in fixing the resin pipe with adhesive rather than with screws.

[0039] It goes without saying that the present invention is not limited in any way to the embodiments described above, and can be implemented in various forms as long as they fall within the technical scope of the present invention.

[0040] In the embodiment described above, a convex ring 62 is provided on the upper surface 61 of the resin pipe 60 along its outermost circumference, but the invention is not limited to this. For example, as shown in Figures 6 and 7, a resin pipe 160 may be used instead of the resin pipe 60 in the embodiment described above. In Figures 6 and 7, the same reference numerals are used for the same components as in the embodiment described above. On the upper surface 61 of the resin pipe 160, a plurality of small protrusions 162 of the same height are provided at equal intervals on a circumference concentric with the resin pipe 60. Even in this case, the adhesive layer 80 can be made thicker compared to the case where the upper surface 61 of the resin pipe 160 is flat, making the adhesive layer 80 less likely to break and the resin pipe 160 less likely to peel off. In this case, the adhesive area between the hole step portion 34c of the base plate through hole 34 and the upper surface 61 of the resin pipe 60 can be easily increased. It is preferable that the circumference on which the plurality of small protrusions 162 are arranged is located on the outer edge side rather than on the resin pipe through hole 64 side. Furthermore, the multiple small protrusions 162 may be arranged at random intervals on a circumference concentric with the resin pipe 60. Also, the multiple small protrusions 162 may be arranged regularly (for example, in a grid pattern) or randomly across the entire upper surface 61 of the resin pipe 60.

[0041] Alternatively, as shown in Figures 8 and 9, a resin pipe 260 may be used instead of the resin pipe 60 in the above-described embodiment. In Figures 8 and 9, the same components as in the above-described embodiment are denoted by the same reference numerals. A convex ring 262 is provided on the upper surface 61 of the resin pipe 260, and is concentric with the resin pipe 260. The convex ring 262 is not in contact with the outer edge of the upper surface 61 of the resin pipe 60, but is provided between the outer edge of the upper surface 61 and the center of the upper surface 61. The outer diameter of the convex ring 62 is smaller than the outer diameter of the upper surface 61 of the resin pipe 60. Even in this case, the adhesive layer 80 can be made thicker compared to the case where the upper surface 61 of the resin pipe 260 is flat, so the adhesive layer 80 is less likely to break and the resin pipe 260 is less likely to peel off. However, since the convex ring 262 is provided between the outer edge of the upper surface 61 and the center of the upper surface 61, the position of the convex ring 262 when it comes into contact with the hole step portion 34c is less stable than in the above-described embodiment.

[0042] In the embodiment described above, the lower end 50a of the insulating tube 50 is positioned to fit into a stepped groove 63 provided on the upper surface 61 of the resin tube 60, but the embodiment is not limited to this. For example, as shown in Figure 10, the stepped groove 63 may not be provided on the upper surface 61 of the resin tube 60, and the lower end 50a of the insulating tube 50 may be in contact with the upper surface 61 of the resin tube 60. Alternatively, as shown in Figure 11, the lower end 50a of the insulating tube 50 may be positioned between the upper surface 61 of the resin tube 60 and the stepped portion 34c of the through-hole 34 of the base plate. In this case, the lower end 50a of the insulating tube 50 is located inside the adhesive layer 80. However, considering the insulation between the power supply member 70 and the base plate 30, it is preferable to position the lower end 50a of the insulating tube 50 to fit into the stepped groove 63 provided on the upper surface 61 of the resin tube 60, as in the embodiment described above. Note that in Figures 10 and 11, the same reference numerals are used for the same components as in the embodiment described above.

[0043] In the embodiment described above, the insulating tube 50 is made of ceramic, but it may also be made of resin. However, since resin generally has lower thermal conductivity than ceramic, the heat dissipation performance of a resin insulating tube 50 is lower than that of a ceramic insulating tube 50. For this reason, it is preferable to use ceramic for the insulating tube 50.

[0044] In the above-described embodiment, a metal layer was exemplified as the bonding layer 40, but it is not particularly limited thereto. For example, a resin layer may be adopted as the bonding layer 40, or an inorganic adhesive may be adopted. Examples of the material of the resin layer include insulating resins such as epoxy resin, acrylic resin, and silicone resin. The bonding layer 40 may be one in which a filler is contained in the insulating resin. The filler preferably has a higher thermal conductivity than the insulating resin of the bonding layer 40, and may be, for example, alumina or aluminum nitride. Note that from the viewpoint of thermal conductivity, the metal layer is more preferable as the bonding layer 40.

[0045] In the above-described embodiment, the ceramic plate 20 incorporated the electrostatic electrode 22, but it is not particularly limited thereto. For example, instead of or in addition to the electrostatic electrode 22, a heater electrode (resistance heating element) may be incorporated, or an electrode for plasma generation (RF electrode) may be incorporated.

[0046] This application claims priority based on Japanese Patent Application No. 2024-158444 filed on September 12, 2024, and the entire content thereof is incorporated herein by reference.

[0047] The present invention can be used in a semiconductor manufacturing apparatus.

[0048] 10 Wafer mounting table, 20 Ceramic plate, 21 Wafer mounting surface, 22 Electrostatic electrode, 24 Bottomed hole of ceramic plate, 30 Base plate, 32 Refrigerant flow path, 32in Inlet, 32out Outlet, 34 Through hole of base plate, *34a Upper part of hole*, *34b Lower part of hole*, *34c Step part of hole*, 40 Bonding layer, 44 Through hole of bonding layer, 50 Insulating tube, 54 Through hole of insulating tube, 60 Resin tube, 62 Convex ring, 63 Step groove, 64 Through hole of resin tube, 70 Power supply member, 80 Adhesive layer, 160 Resin tube, 162 Small projection, 260 Resin tube, 262 Convex ring, G Gap, S Space, W Wafer.

Claims

1. A wafer mounting stand comprising: a ceramic plate having a wafer mounting surface on its upper surface and containing electrodes; a base plate provided on the lower side of the ceramic plate and having a refrigerant flow path inside; a stepped hole penetrating the base plate in the vertical direction and having a small diameter upper hole, a large diameter lower hole, and a hole step between the upper and lower holes, with the lower hole being located below the refrigerant flow path; an insulating tube inserted into the upper hole; a resin tube with a larger diameter than the insulating tube, inserted into the lower hole and with its upper surface bonded to the hole step via an adhesive layer; and a power supply member with its upper surface connected to the electrodes and inserted into the insulating tube and the resin tube, wherein a convex member is provided on the upper surface of the resin tube to secure a gap between the upper surface of the resin tube and the hole step of the stepped hole, and the adhesive layer is filled into the gap.

2. The wafer mounting stage according to claim 1, wherein the convex member is a ring member.

3. The wafer mounting platform according to claim 1 or 2, wherein the convex member is composed of a plurality of small protrusions of the same height.

4. The wafer mounting platform according to claim 1 or 2, wherein the convex member is provided so as to be in contact with the outer edge of the upper surface of the resin tube.

5. The wafer mounting stage according to claim 1 or 2, wherein the height of the convex member is 50 μm or more and 300 μm or less.

6. The wafer mounting stage according to claim 1 or 2, wherein the resin tube is made of engineering plastic.

7. The wafer mounting platform according to claim 1 or 2, wherein the lower end of the insulating tube is fitted into a stepped groove provided on the upper surface of the resin tube.

8. The wafer mounting platform according to claim 1 or 2, wherein the base plate has an average coefficient of linear expansion of 10 ppm / K or less at 40 to 570°C.

9. The wafer mounting stage according to claim 1 or 2, wherein the material of the base plate is a composite material of metal and ceramic.

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