Holding device

Abstract

To provide a holding device which can be improved in property of drawing heat away from a to-be-held object.SOLUTION: An electrostatic chuck 1 is provided, comprising a plate-shaped member 10 (10a, 10b), a base member 20, and a joining layer 30 joining the plate-shaped member 10 and the base member 20. The plate-shaped member 10 has a first region R1 at the center in the plane direction and a second region R2 at the periphery in the plane direction. The joining layer 30 has a first joining layer 30a arranged between the base member 20 and the first region R1, and a second joining layer 30b arranged between the base member 20 and the second region R2. The thermal conductivity of the first joining layer 30a is greater than the thermal conductivity of the second joining layer 30b. The Young's modulus of the first joining layer 30a is greater than the Young's modulus of the second joining layer 30b.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present disclosure relates to a holding device for holding an object.

Background Art

[0002] In the semiconductor manufacturing process, an electrostatic chuck (holding device) is used to hold a semiconductor wafer. As such an electrostatic chuck, a ceramic substrate (plate-like member) for holding an object on a mounting surface (holding surface), and a base (base member) joined to the ceramic substrate via a joining layer are widely known. And, in order to make the temperature distribution on the mounting surface uniform, for example, in the one described in Patent Document 1, the joining layer is divided into a central portion and its outer peripheral portion, and the thermal conductivity of the joining layer (second joining material) in the outer peripheral portion is made higher than the thermal conductivity of the joining layer (first joining material) in the central portion.

[0003]

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, in the above-described electrostatic chuck, since the thermal conductivity of the joining layer in the central portion is lower than the thermal conductivity of the joining layer in the outer peripheral portion, heat transfer in the central portion becomes worse than heat transfer in the outer peripheral portion. Therefore, in the central portion of the object being held, heat transfer (heat extraction) from the object to the base (base member) deteriorates, and the temperature of the object cannot be efficiently reduced.

[0005] ​That's a possibility. In other words, there's a risk that the heat dissipation from the object being held will deteriorate.

[0005] Furthermore, in recent years, high voltages have been applied to electrostatic chucks (they are used at high power). It is increasing. As a result, the temperature of the object being held becomes higher than before. As the temperature increases, the efficiency of the process on the object decreases, therefore the object The requirement is for heat dissipation capabilities that can lower the temperature in a short time (improved heat dissipation capabilities).

[0006] Therefore, this disclosure is made to resolve the above-mentioned problems, and the subject matter is The objective is to provide a holding device that can improve heat dissipation from objects. [Means for solving the problem]

[0007] One form of this disclosure made to solve the above problem is: A plate-shaped member, a base member, and a bonding layer that joins the plate-shaped member and the base member, In a holding device, The plate-like member has a first region in the center in the plane direction and a second region in the outer periphery in the plane direction. The bonding layer comprises a first bonding layer disposed between the first region and the base member, and It has a second bonding layer disposed between the second region and the base member, The thermal conductivity of the first bonding layer is greater than the thermal conductivity of the second bonding layer. The Young's modulus of the first bonding layer is greater than that of the second bonding layer. .

[0008] In this holding device, the thermal conductivity of the first bonding layer is made greater than that of the second bonding layer. This allows the heat between the plate-like member and the base member in the first region via the first bonding layer to be released. Movement can be promoted. Therefore, heat transfer from the object to be held to the plate-like member and the base member is efficiently performed, so that the heat extraction property from the object to be held can be improved .

[0009] Also, by making the Young's modulus of the first bonding layer larger than that of the second bonding layer, at the outer peripheral portion where the heat deformation of the base member tends to be large, the thermal expansion difference between the plate-like member and the base member can be firmly absorbed by the second bonding layer. Therefore, when thermal deformation occurs in the holding device, at the outer peripheral portion where poor bonding between the base member and the plate-like member is likely to occur, the second bonding layer can prevent the occurrence of poor bonding between the base member and the plate-like member.

[0010] In the holding device described above, it is preferable that the first bonding layer is formed separately from the second bonding layer.

[0011] Thus, since the first bonding layer and the second bonding layer are separated in the bonding layer, the arrangement positions of the first bonding layer and the second bonding layer can be freely adjusted in the thickness direction . Thereby, the thicknesses of the plate-like member in the first region and the second region can be independently controlled , so that the heat extraction property from the object to be held can be further improved. Also, the balance of heat transfer in the first region and the second region can be adjusted . .

[0012] Also, in any of the holding devices described above, it is preferable that the first bonding layer is formed of a bonding material mainly composed of a metal material.

[0013] Thus, by forming the first bonding layer of a bonding material mainly composed of a metal material, the first ​​​Heat transfer between the plate-like member and the base member in the area can be further promoted. Therefore, since heat transfer from the object to be held to the plate-like member and the base member is performed more efficiently, the heat extraction performance from the object to be held can be further improved.

[0014] Also, in any of the holding devices described above, the plate-like member is formed of ceramics, and it is preferable that the base member is formed of ceramics or a metal-ceramics composite material. That is.

[0015] Thus, by forming the base member of ceramics or a metal-ceramics composite material, the difference in thermal expansion coefficient between the plate-like member and the base member can be reduced. Therefore, even when a metal bonding material is used, the plate-like member and the base member can be firmly joined. Therefore, even when the plate-like member and the base member are joined using a metal bonding material, no poor bonding occurs. As a result, heat transfer from the object to be held to the plate-like member and the base member is efficiently performed, and the heat extraction performance from the object to be held can be improved.

[0016] Also, when the plate-like member and the base member are joined using a resin bonding material, the thickness of the bonding layer can be made thinner. Therefore, compared with the conventional device, heat transfer from the object to be held to the plate-like member and the base member is promoted, and the heat extraction performance from the object to be held can be improved. That is.

[0017] Also, in any of the holding devices described above, it is preferable that the thickness of the first bonding layer is less than or equal to the thickness of the second bonding layer.

[0018] A thinner bonding layer improves heat dissipation, while a thicker layer provides stress relaxation. Therefore, by making the thickness of the first bonding layer less than or equal to the thickness of the second bonding layer, the inside of the bonding layer ( The first bonding layer can improve heat dissipation, while the outer layer (second bonding layer) can improve heat dissipation. It can absorb the difference in expansion. Therefore, heat dissipation is improved on the inside of the bonding layer (first bonding layer). This allows the outer layer (second bonding layer) to absorb the difference in thermal expansion, thus creating an effect in such bonding layers. The effect can be further enhanced by controlling the thickness.

[0019] Furthermore, in any of the above-mentioned holding devices, A connecting electrode is formed on the surface of the base member. Preferably, the connecting electrode is electrically connected to the first junction layer.

[0020] In this way, by forming connecting electrodes on the surface of the base member, the metal material is used. Since the first bonding layer can be used as a high-frequency electrode, the internal electrical components provided within the plate-shaped member The poles can be reduced. This reduces the plate-like portion of the area where the object is placed (first area). Because the thickness of the material can be reduced, heat dissipation can be further improved. Also, Since it is not necessary to provide through holes in the base member for arranging connection terminals, the object can be preserved. It can also improve the uniformity of heat distribution on the holding surface.

[0021] Furthermore, in order to ensure the insulation of the connecting electrodes, the connecting electrodes are insulated by thermal spraying or other methods. It will do well if you cover it with a film.

[0022] Furthermore, in any of the above-mentioned holding devices, The base member is formed by stacking multiple members, It is preferable that the materials of the aforementioned multiple components are different.

[0023] In this way, by forming the base member by stacking multiple members, the plate-shaped member comes into contact with the base member. The part on the surface side has a small difference in thermal expansion coefficient with the plate-like member and a high thermal conductivity (for example, metal). Using ceramic composite materials, etc., the opposite side has a surface that contacts the plate-shaped member and Different materials (for example, ceramics, etc.) can be used.

[0024] This configuration allows for improved heat dissipation of the plate-shaped member, and also... The ability to prevent foreign matter from being generated from through holes in the member (e.g., lift pin holes, gas holes, etc.) It can be improved. As a result, in the chamber of semiconductor manufacturing equipment that uses a holding device It can prevent contamination.

[0025] Furthermore, because the materials of the multiple components are different, the surface portion that contacts the plate-shaped member and On the opposite side, a component made of a different material can be used. Therefore, on the side opposite to the surface in contact with the plate-shaped member, for example, a material that is easy to process or an inexpensive material is used. By using these components, the productivity (machinability) of the holding device is improved, as well as the manufacturing cost. It can also be reduced.

[0026] Another form of this disclosure made to solve the above problems is: A plate-shaped member, a base member, and a bonding layer that joins the plate-shaped member and the base member, In a holding device, The plate-like member has a first region in the center in the plane direction and a second region in the outer periphery in the plane direction. The bonding layer comprises a first bonding layer disposed between the first region and the base member, and It comprises a second bonding layer disposed between the second region and the base member, The first bonding layer is formed spaced apart from the second bonding layer. The first bonding layer is characterized by being formed of a bonding material mainly composed of a metal material. .

[0027] In this holding device, since the first bonding layer is formed of a metal bonding material, in the first region This can promote heat transfer between the plate-shaped member and the base member. Therefore, the object to be held... Because heat transfer from the object being held is efficiently performed to the plate-shaped member and the base member, This can improve heat dissipation.

[0028] Furthermore, it has a first bonding layer and a second bonding layer which are formed with a gap between them. In the thickness direction, the positioning of the first bonding layer and the second bonding layer can be freely adjusted. This is possible. Therefore, the thickness of the plate-like member in the first region can be reduced, This allows for improved heat dissipation from the object being held. Furthermore, the first and second regions... It is also possible to adjust the balance of heat transfer in each region. [Effects of the Invention]

[0029] According to this disclosure, a holding device is provided that can improve the heat dissipation from the object being held. It can be provided. [Brief explanation of the drawing]

[0030] [Figure 1] This is a schematic perspective view of the electrostatic chuck according to the embodiment. [Figure 2] This is a schematic diagram of the XZ cross-section of the electrostatic chuck according to the embodiment. [Figure 3] This is a cross-sectional view of the base member in a modified electrostatic chuck. [Modes for carrying out the invention]

[0031] The holding device, which is an embodiment of the present disclosure, will be described in detail with reference to the drawings. In this embodiment, the holding device is, for example, an etching device (a plasma etching device, etc.). Semiconductor manufacturing equipment such as (and) and thin-film deposition equipment (CVD deposition equipment, sputtering deposition equipment, etc.) An example of an electrostatic chuck used for installation will be provided to illustrate the point.

[0032] Therefore, the electrostatic chuck 1 of this embodiment will be described with reference to Figures 1 and 2. The electrostatic chuck 1 of this embodiment is a device that holds a semiconductor wafer W by attracting it with electrostatic force. For example, to fix a semiconductor wafer W in a vacuum chamber of a semiconductor manufacturing apparatus. It is used for the following. As shown in Figures 1 and 2, the electrostatic chuck 1 consists of a plate-shaped member 10 and a base part It comprises a material 20 and a bonding layer 30 that joins the plate-shaped member 10 and the base member 20.

[0033] For the sake of clarity, the XYZ axes are defined as shown in Figure 1 in the following explanation. The Z-axis is the axis in the axial direction (up and down direction in Figure 1) of the electrostatic chuck 1, and the X-axis and Y-axis This is the radial axis of the electrostatic chuck 1. Also, the direction of the XY plane is the "plane direction" of this disclosure. This is just one example.

[0034] As shown in Figure 1, the plate-shaped member 10 is a disc-shaped member and is made of ceramics. Specifically, the plate-shaped member 10 has a first region R1 in the center of the XY plane direction (surface direction). The inner part 10a is located at the XY plane (surface direction), and the outer part is located in the second region R2 at the outer periphery. It has side portions 10b and a convex central portion. And the inner portion 10 of the plate-shaped member 10 A semiconductor wafer W is placed on the upper surface 11a of a (first region R1), and the outer part 1 of the plate-shaped member 10 An annular member (Focus Ri) surrounding the semiconductor wafer W is located on the upper surface 11b of 0b (second region R2). A FR (Ring FR) will be placed.

[0035] Various ceramics can be used to form the plate-shaped member 10. However, from the viewpoint of strength, wear resistance, plasma resistance, etc., for example, aluminum oxide (aluminum Ceramics mainly composed of aluminum nitride (Al2O3) or aluminum nitride (AlN) are used. It is preferable that this be done. Note that the main component referred to here is the component with the highest proportion (for example) This refers to components with a volume content of 90 vol% or more.

[0036] The inner portion 10a of the plate-shaped member 10 is disc-shaped, as shown in Figures 1 and 2, and is a semiconductor material. The upper surface 11a is a holding surface that holds the w, and the Z-axis direction is provided on the opposite side from the upper surface 11a. It is equipped with a lower surface 12a. The diameter of the inner part 10a is, for example, 150 mm to 300 mm. It is approximately as follows. Furthermore, the thickness of the inner part 10a is, for example, about 1 mm to 10 mm. The thermal conductivity of the inner part 10a is 10 W / mK to 50 W / mK (more preferably 18 W / mK). A range of K to 33 W / mK is desirable.

[0037] As shown in Figure 2, the inner portion 10a of such a plate-shaped member 10 contains a chuck electric It is equipped with poles 50. The chuck electrode 50 is, for example, approximately circular in shape when viewed in the Z-axis direction. It is made of a conductive material (for example, tungsten or molybdenum). The electrode 50 is electrically connected via vias 61 and terminal pads 62 (not shown). The power supply terminal 63, which is connected to an external power supply, is electrically connected. Note that via 61 and terminal The pad 62 is formed of a conductive material (for example, tungsten or molybdenum). Then, the power supply terminal 63, terminal pad 62 and via 61 are connected to the external power supply. When a voltage is applied to electrode 50, an electrostatic attraction (adsorption force) is generated, and this electrostatic attraction The semiconductor wafer W is then adsorbed and fixed to the upper surface 11a.

[0038] The outer portion 10b of the plate-shaped member 10 is annular, as shown in Figures 1 and 2, and the focus The upper surface 11b on which the ring FR is positioned, and the side opposite to the upper surface 11b in the Z-axis direction. It is equipped with a lower surface 12b. The outer diameter of the outer part 10b is, for example, about 180mm to 400mm. The outer part 10b has a thickness of approximately 1 mm to 10 mm. The thermal conductivity of part 10b is 10 W / mK to 50 W / mK (more preferably 18 W / mK to 50 W / mK). A range of 33 W / mK is desirable.

[0039] As shown in Figure 2, the outer portion 10b of such a plate-shaped member 10 has a chuck inside. It is equipped with an electrode 51. The chuck electrode 51 has, for example, a roughly annular shape when viewed in the Z-axis direction. It is formed from a conductive material (for example, tungsten or molybdenum). The buck electrode 51 is electrically connected via 64 and terminal pad 65, as shown in the figure. The power supply terminal 66, which is connected to an external power supply, is electrically connected. Voltage is supplied to the chuck electrode 51 via the power supply terminal 66, terminal pad 65 and via 64. When applied, electrostatic attraction (attraction force) is generated, and this electrostatic attraction causes the focus ring FR to move. It is adsorbed and fixed to the upper surface 11b.

[0040] Furthermore, the outer portion 10b of the plate-shaped member 10 is equipped with a high-frequency electrode 52 inside. The wave electrode 52, when viewed in the Z-axis direction, is for example, roughly annular in shape and is made of a conductive material (for example, tan). It is formed from gusten or molybdenum, etc. This high-frequency electrode 52 is electrically connected The power supply terminal is connected to an external power supply (not shown) via the connected via 67 and terminal pad 68. Child 69 is electrically connected. Vias 64, 67 and terminal pads 65, 68 are It is made of a conductive material (for example, tungsten or molybdenum).

[0041] As shown in Figure 1, the base member 20 is positioned on the lower side of the plate-shaped member 10. The base member 20 is formed, for example, in a cylindrical shape, and in this embodiment, the first of the plate-shaped member 10 The portion that joins with region R1 (inner part 10a) is convex. 20 is, for example, ceramics (e.g., SiC) or metal-ceramic composite materials (Ti / It is formed from SiC composite material, MMC (Al / SiC composite material), etc. This makes it possible to reduce the difference in thermal expansion coefficients between the base member 20 and the plate-shaped member 10.

[0042] Then, as shown in Figures 1 and 2, the base member 20 has an inner part of the plate-shaped member 10 on its upper side. The upper surface 21a to which 10a is joined and the upper surface 21b to which the outer part 10b of the plate-shaped member 10 is joined It also includes a lower surface 22 provided on the opposite side of the upper surfaces 21a and 21b in the Z-axis direction. Furthermore, the upper surfaces 21a and 21b of the base member 20 are below the inner portion 10a of the plate-shaped member 10. Surface 12a and the lower surface 12b of the outer part 10b of the plate-shaped member 10, and the bonding layer 30 (30a, 30b They are thermally connected via ).

[0043] The diameter of the base member 20 is, for example, about 180 mm to 400 mm. The thickness of material 20 (dimension in the Z-axis direction) is, for example, about 20mm to 50mm. The thermal conductivity of component 20 (assuming ceramics or MMC) is 30 W / mK to 200 A range of W / mK (preferably around 100 W / mK) is desirable.

[0044] A refrigerant (for example, a fluorine-based inert liquid or water) is flowed through such a base member 20. A refrigerant flow path 23 is formed. By flowing refrigerant through this refrigerant flow path 23, The member 20 is cooled, and the plate-shaped member 10 is cooled via the bonding layer 30. This cools the semiconductor wafer W, whose temperature rises during various process operations, and the semiconductor Heat is removed from the wafer W.

[0045] Furthermore, connecting electrodes 70 may be formed on the surface of the base member 20. Therefore, it is also acceptable if the connecting electrode 70 is formed on the entire surface of the base member 20 except for the upper surface 21a. i. This connecting electrode 70 is made by, for example, spraying aluminum (cold spray method) and the base This can be manufactured by forming a coating on the surface of the component 20. This connecting electrode 70 is It is electrically connected to the first bonding layer 30a, which will be described later. In addition, the connecting electrode 70 has a base A power supply terminal 71 connected to a high-frequency power supply is connected to the lower surface 22 side of the member 20. Oh, the connecting electrode 70 only needs to be shaped in a way that it can supply power to the first bonding layer 30a, and the base member 20 It does not need to be formed on the entire surface, but rather on a part of the surface of the base member 20. They may be present, or they may be formed in a manner that excludes a portion of the entire surface of the base member 20.

[0046] Furthermore, in order to ensure the insulation of the connecting electrode 70, the connecting electrode 70 is covered with an insulating film 72. In other words, in this embodiment, the connecting electrode 70 is located on the surface of the base member 20 excluding the upper surface 21a. Because it is formed over the entire surface, the entire surface of the base member 20, excluding the upper surface 21a, is covered by the insulating film 72. It is covered with a solvent. This insulating film 72 is made of, for example, alumina, anodized aluminum, yttria, etc. It can be formed by injection.

[0047] Furthermore, the base member 20 has a structure that penetrates the space between the upper surfaces 21a, 21b and the lower surface 22 in the Z-axis direction. Through holes 24, 25, 26 are formed. These through holes 24, 25, 26 are for supplying These are holes for arranging electrical terminals 63, 66, and 69.

[0048] Furthermore, the base member 20 has the upper surfaces 11a and 11b of the plate-shaped member 10 and the semiconductor held there An inert gas (e.g., He gas) is introduced into the minute space between EHA W and the focus ring FR. The gas holes 15 and 16 for supplying gas, and the semiconductor wafer W held on the upper surface 11a are lifted. A through hole is also formed, which is part of the lift pin hole 17 for arranging the lift pin. Yes, they are.

[0049] The bonding layer 30 is positioned between the plate-shaped member 10 and the base member 20, as shown in Figures 1 and 2. The plate-shaped member 10 and the base member 20 are joined together. This joining layer 30 is connected to the plate-shaped member 1 A first bonding layer 30 is placed between the first region R1 (inner part 10a) of 0 and the base member 20. a is positioned between the second region R2 (outer part 10b) of the plate-shaped member 10 and the base member 20. It has a second bonding layer 30b.

[0050] As shown in Figure 2, the first bonding layer 30a is formed on the lower surface 12a of the inner portion 10a of the plate-shaped member 10 and It is positioned between the upper surface 21a of the base member 20 and the inner part 10a and the base member 20, and heat transfers between them. The materials are joined in a way that allows them to reach each other. This first joining layer 30a is a metal joining material whose main component is a metal material. It is composed of the following. As such a metal bonding material, for example, metal powder or metal foil is used. Metal adhesives for joining, metal fibers, porous materials, mesh structures, and brazing materials. This may consist of, or of, multiple columnar metal pieces and brazing material. It is possible. As the metal used to form metal adhesives, metal meshes, and metal pieces, aluminum is used. Indium, titanium, nickel, copper, brass, alloys thereof, or stainless steel, etc. It can be used. Note that "primarily composed of metal materials" means that the bonding material contains metal components. This means that it contains the most of [the substance].

[0051] The thickness of this first bonding layer 30a (dimension in the Z-axis direction) is, for example, 0.05 mm to 0.5 mm. The thickness is approximately (preferably 0.1 mm to 0.3 mm). The thermal conductivity of the first bonding layer 30a is, for example, For example, 100W / mK to 200W / mK (preferably 150W / mK to 180W / mK) A range within this spectrum is desirable. Furthermore, the Young's modulus of the first bonding layer 30a should be, for example, 0.5 GPa to 10 A range of 0 GPa (preferably 20 GPa to 80 GPa) is desirable.

[0052] As shown in Figure 2, the second bonding layer 30b is formed on the lower surface 12b of the outer portion 10b of the plate-shaped member 10 and It is positioned between the upper surface 21b of the base member 20 and the outer part 10b, and heat transfers between the outer part 10b and the base member 20. The second bonding layer 30b is made of, for example, a silicone resin or an acrylic resin. It is composed of resin adhesives such as resins and epoxy resins.

[0053] The thickness of this second bonding layer 30b (dimension in the Z-axis direction) is, for example, 0.05 mm to 0.5 mm. The thickness is approximately (preferably 0.1 mm to 0.5 mm). Also, the thermal conductivity of the second bonding layer 30b For example, this is 1.0 W / mK. Note that the second bonding layer 30b (assuming a silicone-based resin) The thermal conductivity is 0.1 W / mK to 2.0 W / mK (preferably 0.5 W / mK to 1.5 A range of W / mK is desirable. Also, the Young's modulus of the second bonding layer 30b should be, for example, 0.5M. A range of Pa ~ 100 MPa (preferably 1 MPa ~ 10 MPa) is desirable.

[0054] Furthermore, in this embodiment, in the bonding layer 30, the first bonding layer 30a and the second bonding layer 30b are They are formed with a gap between them. Specifically, the first bonding layer 30a and the second bonding layer 30b are separated. An insulating film 72 is formed in the space. The thermal conductivity of the first bonding layer 30a is The thermal conductivity of the second bonding layer 30b is greater than that of the first bonding layer 30a. However, it is greater than the Young's modulus of the second bonding layer 30b. Furthermore, the first bonding layer 30a The thickness is smaller (thinner) than the thickness of the second bonding layer 30b.

[0055] The electrostatic chuck 1 having the above configuration is manufactured by the following procedure. First, the plate-shaped member 10 The inner portion 10a is joined to the upper surface 20a of the base member 20 via the first bonding layer 30a. Then, a connecting electrode 70 is formed on the surface of the base member 20. And, so as to cover the connecting electrode 70 Next, an insulating film 72 is formed on the surface of the base member 20. Finally, the outer portion 10b of the plate-shaped member 10 The upper surface 21b of the base member 20 (more specifically, the insulating film 72 formed on the upper surface 21b) The two bonding layers are joined via a second bonding layer 30b. The first bonding layer 30a and the second bonding layer are spaced apart. An insulating film 72 is located between the composite layer 30b and the other layer. Subsequently, processing and other operations are carried out on each part. And with that, electrostatic chuck 1 is complete.

[0056] In this embodiment of the electrostatic chuck 1, the plate-shaped member 10 is located in the first region R1. It has an inner portion 10a and an outer portion 10b located in the second region R2. 30 comprises a first bonding layer 30a and a second bonding layer 30b, and via the first bonding layer 30a The inner portion 10a of the plate-shaped member 10 is joined to the base member 20 via the second joining layer 30b. The outer portion 10b of the plate-shaped member 10 is joined to the base member 20.

[0057] Furthermore, the thermal conductivity of the first bonding layer 30a is greater than that of the second bonding layer 30b. The first region R1 (inner part 10a) of the plate-shaped member 10 and the base member are separated by the first bonding layer 30a. This can facilitate heat transfer between 20 and the semiconductor wafer W. Because heat transfer to member 10 and base member 20 is carried out efficiently, the high temperature of the semiconductor The EHA W can be cooled efficiently in a short time. In other words, from the semiconductor wafer W being held This can improve the heat dissipation performance.

[0058] Furthermore, since the Young's modulus of the first bonding layer 30a is greater than that of the second bonding layer 20b, The difference in thermal deformation between the base member 20 and the plate-shaped member 10 tends to be large for the plate-shaped member 10. In the second region R2, the difference in thermal expansion between the plate-shaped member 10 (outer part 10b) and the base member 20 is The second bonding layer 30b can absorb the heat effectively. Therefore, the electrostatic chuck 1 does not undergo thermal deformation. When this occurs, poor bonding is likely to occur between the base member 20 and the plate-shaped member 10. In the second region R2 (outer part 10b), the base member 20 and the plate are joined by the second bonding layer 30b. This prevents the occurrence of poor bonding with the shaped member 10.

[0059] Furthermore, since the first bonding layer 30a is formed with a bonding material whose main component is metal, the plate-shaped member In the first region R1 of 10, heat transfer between the base member 20 and the region can be further promoted. This allows for improved heat dissipation from the semiconductor wafer W being held. .

[0060] Here, if a metal bonding material is used, the difference in thermal expansion coefficient between the plate-shaped member 10 and the base member 20 becomes large. If the electrostatic chuck 1 is thermally deformed, there is a risk of a faulty connection occurring. In the electrostatic chuck 1, the base member 20 is made of ceramics or a metal-ceramic composite material. It is forming.

[0061] Therefore, since the difference in thermal expansion coefficient between the plate-shaped member 10 and the base member 20 is small, the first bonding layer 3 Even if a metal bonding material is used in 0a, the plate-shaped member 10 and the base member 20 will be firmly joined. Therefore, the first bonding layer 30a using a metal bonding material allows the first bonding of the plate-shaped member 10 This prevents poor bonding between region R1 and the base member 20. Heat transfer from the semiconductor wafer W to the plate-shaped member 10 (inner part 10a) and the base member 20. Because the movement is carried out efficiently, the heat dissipation from the semiconductor wafer W can be improved.

[0062] Furthermore, since the difference in thermal expansion coefficients between the plate-shaped member 10 and the base member 20 is small, the plate-shaped member 10 Even if the thickness of the second bonding layer 30b that joins the two regions R2 and the base member 20 is reduced, bonding defects persist. This does not occur. Therefore, the thickness of the second bonding layer 30b using the resin bonding material is reduced. Therefore, compared to conventional devices, the focus ring FR and semiconductor wafer W that are held are This promotes heat transfer to the plate-shaped member 10 and the base member 20. As a result, the electrostatic chuck The heat dissipation performance in step 1 can be further improved.

[0063] Furthermore, in the bonding layer 30, the first bonding layer 30a and the second bonding layer 30b are made into separate structures. Therefore, the first bonding layer and the second bonding layer are separated. As a result, in the Z-axis direction, the first bonding layer The positions of the bonding layer 30a and the second bonding layer 30b can be freely adjusted. This makes it possible to reduce the thickness of the first region R1 (inner portion 10a) of the plate-shaped member 10. Therefore, the heat dissipation from the semiconductor wafer W being held can be further improved. In member 10, the balance of heat transfer between the first region R1 and the second region R2. You can also adjust it.

[0064] Furthermore, the thickness of the first bonding layer 30a is less than or equal to the thickness of the second bonding layer 30b. The thickness of the joint is important because a thinner joint improves heat dissipation, while a thicker joint provides stress relief. The heat dissipation can be improved on the inside of layer 30 (first bonding layer 30a), and on the outside (The second bonding layer 30b) can absorb the difference in thermal expansion. In this way, bonding layer 30( By controlling the thickness of the first bonding layer 30a and the second bonding layer 30b, the inside of the bonding layer 30 The first bonding layer 30a located on the outside has improved heat dissipation, and the second bonding layer 30b located on the outside This further enhances the effect of absorbing the difference in thermal expansion.

[0065] Furthermore, in the electrostatic chuck 1, a connecting electrode 70 is formed on the surface of the base member 20, and the connection The electrode 70 is electrically connected to the first bonding layer 30a. And the lower surface of the base member 20 On side 22, the power supply terminal 71, which is connected to the high-frequency power supply, is connected to the connecting electrode 70. .

[0066] This allows the first bonding layer 30a to be used as a high-frequency electrode. Therefore, The number of internal electrodes provided in the first region R1 of the plate-shaped member 10 can be reduced. Therefore, The portion of the plate-shaped member 10 located in the region (first region R1) on which the semiconductor wafer W is placed ( This allows the thickness of the inner part 10a) to be reduced, thus improving heat dissipation from the semiconductor wafer W. It can be further improved. Also, through holes for arranging power supply terminals in the base member 20 Since it becomes unnecessary to provide a [specific component], the uniform heat distribution on the upper surface 11a that holds the semiconductor wafer W is improved. It can also be raised.

[0067] As described above, according to the electrostatic chuck 1 of this embodiment, the bonding layer 30 is the first bonding layer 30a The first bonding layer 30a is provided with a second bonding layer 30b, and the thermal conductivity of the first bonding layer 30a is equal to that of the second bonding layer 30b. It is greater than the thermal conductivity. Therefore, the first region R1 of the plate-shaped member 10 via the first bonding layer 30a This can promote heat transfer between the base member 20 and the semiconductor. Because heat transfer from the wafer W to the plate-shaped member 10 and the base member 20 is performed efficiently, This improves the heat dissipation from the conductive wafer W. As a result, the semiconductor becomes hotter. The temperature of the wafer W can be reduced in a short time.

[0068] Furthermore, since the Young's modulus of the first bonding layer 30a is greater than that of the second bonding layer 30b, In the second region R2 of the plate-shaped member 10, where the difference in thermal deformation with the base member 20 tends to be large, The difference in thermal expansion between the plate-shaped member 10 (outer part 10b) and the base member 20 is transferred to the second bonding layer 30b. Therefore, it can be absorbed effectively. Consequently, thermal deformation occurs in the electrostatic chuck 1. When this occurs, the second region R2 of the plate-shaped member 10, which is prone to bonding defects with the base member 20, Then, the second bonding layer 30b connects the base member 20 and the plate-shaped member 10 (outer part 10b). This can prevent the occurrence of fitting defects.

[0069] <Variation> Next, a modified example of the above embodiment will be described with reference to Figure 3. The basic configuration is the same as the embodiment described above, but it consists of multiple members made of different base material materials. The difference lies in the fact that it is composed of the same components. Therefore, the same reference numerals are used for components that are the same as those in the above embodiment. Therefore, I will omit that explanation and focus on explaining the differences.

[0070] In the modified electrostatic chuck 1a, as shown in Figure 3, the base member 120 is the first base It comprises a base member 121 and a second base member 122. And the first base member 121 and The second base member 122 is joined and integrated by the base bonding layer 123. The base member 120 is formed by stacking multiple members.

[0071] The first base member 121 is made of the same material as the base member 20 in the above embodiment. For example, ceramics (e.g., SiC) or metal-ceramic composite materials (Ti / SiC composite) It is formed from composite materials, such as MMC (Al / SiC composite material). On the other hand, the second base The member 122 is made of the same material as the plate-shaped member 10 in the above embodiment (for example, an oxidized material). It is mainly composed of aluminum (alumina, Al2O3) or aluminum nitride (AlN). It is formed from ceramics, etc.

[0072] Then, on the upper surface side of the first base member 121, plate-shaped members 10 (first plate-shaped member 10a, second A plate-shaped member 10b) is joined to it. In other words, similar to the embodiment described above, the plate-shaped member 10 is joined to it. In contrast, the first base member 121 has a small difference in thermal expansion coefficient with the plate-shaped member 10 and high thermal conductivity. The two are joined together. Therefore, the heat dissipation of the plate-shaped member 10 can be improved, and the plate-shaped member 1 This prevents the occurrence of poor bonding between component 0 and the base member 20.

[0073] On the other hand, the lower surface side of the first base member 121 is made of a different material from the first base member 121. A second base member 122, made of a material with excellent corrosion resistance, is joined to it. While the body itself has sufficient corrosion resistance, the second base component is made of ceramics, which has even better corrosion resistance. By forming 122, through holes (for example, gas holes 15 or lifts) in the base member 120 are formed. This prevents foreign matter from being generated from pin holes 17, etc. Therefore, electrostatic chuck 1a is used. This can prevent contamination inside the chamber of the semiconductor manufacturing equipment used.

[0074] Furthermore, in the base member 120, it is positioned on the opposite side from the upper surface that is in contact with the plate-shaped member 10. For the second base component, use a material that is easy to process and inexpensive (for example, alumina). This improves the productivity (machining performance) of the electrostatic chuck 1a and lowers manufacturing costs. It can also be reduced.

[0075] According to the modified electrostatic chuck 1a, the base member 120 is connected to multiple members ( The first base member 121 and the second base member 122 are stacked to form the first base member 1 For 21, a material with a small difference in thermal expansion coefficient from the plate-shaped member 10 and high thermal conductivity is used, and the second bell The component 122 uses a material that has excellent corrosion resistance, is easy to process, and is inexpensive. This improves the heat dissipation of the plate-shaped member 10, and also improves the through-holes of the base member 120. This prevents the generation of foreign matter from (for example, gas holes 15 or lift pin holes 17). Furthermore, to improve the productivity (machining performance) of the electrostatic chuck 1a and reduce manufacturing costs. It can also be done this way.

[0076] The above embodiments are merely illustrative examples and do not limit the present disclosure in any way. Of course, various improvements and modifications are possible as long as they do not deviate from the gist of the text. In the above embodiment, the plate-shaped member 10 has a separate structure consisting of an inner portion 10a and an outer portion 10b. The example given shows that they are separated, but the inner part 10a and the outer part 10b are integrated. This disclosure can be applied even if [the information is missing].

[0077] Furthermore, although the above embodiment illustrates the case in which the first bonding layer 30a is formed with a metal bonding material, The first bonding layer 30a has a higher thermal conductivity and a higher Young's modulus than the second bonding layer 30b. The application is not limited to metal bonding materials. For example, the first bonding layer 30a has higher thermal conductivity than the second bonding layer. It can also be formed with a resin bonding material that has a high ratio and Young's modulus. The first bonding layer 30a When using resin adhesives, for example, silicone resins, acrylic resins, and epoxy resins are used. These can be used. Also, by changing the amount of filler added, the first bonding layer can be changed. The thermal conductivity and Young's modulus of 30a can be made greater than those of the second bonding layer 30b.

[0078] Furthermore, although the above embodiment illustrates the case in which the second bonding layer 30b is formed with a resin bonding material, The second bonding layer 30b has a lower thermal conductivity and a lower Young's modulus than the first bonding layer, and the resin The bonding material is not limited to this. For example, the second bonding layer 30b has higher thermal conductivity than the first bonding layer 30a. It can also be formed with a metal bonding material having a low ratio and Young's modulus. The second bonding layer 30b When using metal joining materials, for example, aluminum, indium, titanium, nickel, copper, Brass, these alloys, or stainless steel can be used.

[0079] Furthermore, in the above embodiment, a connecting electrode 70 is formed on the surface of the base member 20. The above examples illustrate the case where the base member 20 is conductive (for example, if the base member is made of metal or MM If formed of C, the connecting electrode 70 does not need to be formed. The base member 20 is conductive This is because, when held, the base member 20 and the first bonding layer 30a can be electrically connected. [Explanation of symbols]

[0080] 1. Electrostatic Chuck 10 Plate-shaped member 10a Inner part 10b Outer part 20 Base members 30 Bonding layer 30a 1st bonding layer 30b 2nd bonding layer 70 Connecting electrodes 120 Base member 121 First base member 122 Second base member 123 Base bonding layer FR Focus Ring R1 1st area R2 2nd area W Semiconductor wafer

Claims

1. A holding device comprising a plate-shaped member, a base member having a refrigerant flow path formed therein, and a bonding layer that joins the plate-shaped member and the base member, The plate-like member has a first region in the center in the plane direction and a second region in the outer periphery in the plane direction. The bonding layer comprises a first bonding layer disposed between the first region and the base member, and a second bonding layer disposed between the second region and the base member. The first bonding layer is formed spaced apart from the second bonding layer. The first bonding layer is formed of a bonding material mainly composed of a metal material. A connecting electrode is formed on the surface of the base member. The connecting electrode is electrically connected to the first bonding layer. The base member has a first bottom surface facing the plate-shaped member, a second bottom surface provided on the opposite side of the first bottom surface, and a side surface connecting the first bottom surface and the second bottom surface. The connecting electrode is provided on the side surface of the base member. A holding device characterized by the following features.

2. In the holding device described in claim 1, The plate-like member is made of ceramics, The base member is formed of ceramics or a metal-ceramic composite material. A holding device characterized by the following features.

3. In the holding device described in claim 1, The thickness of the first bonding layer is less than or equal to the thickness of the second bonding layer. A holding device characterized by the following features.

4. In the holding device described in claim 1, The base member is formed by stacking multiple members, The materials of the aforementioned multiple components are different. A holding device characterized by the following features.

5. In the holding device described in Claim 1, An insulating film is formed on the surface of the connecting electrode. A holding device characterized by the following features.

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