Substrate, electrostatic chuck device, and method for manufacturing substrate

Abstract

The present invention provides a novel base using MMC as a material, a novel electrostatic chuck device having such a base, and a base manufacturing method capable of easily manufacturing such a base. The base is provided with: a first member made of a metal-based composite material; a second member which is made of a metal-based composite material and which overlaps the first member; and an adhesive layer which is made of an organic material and which adheres the first member and the second member, the first member having a ridge portion on the side facing the second member, and the adhesive layer being sandwiched between the top surface of the ridge portion and the surface of the second member facing the first member. A space surrounded by the second member and the groove portion formed between adjacent ridge portions is a flow path through which a refrigerant flows.

Description

Technical Field

[0001] The present invention relates to a pedestal, an electrostatic chuck device, and a method for manufacturing a pedestal. Background Art

[0002] Conventionally, in semiconductor manufacturing processes for manufacturing semiconductors such as ICs, LSIs, and VLSIs, when performing plasma processing on a plate-shaped specimen such as a silicon wafer, an electrostatic chuck device that electrostatically adsorbs the plate-shaped specimen is used. In the plate-shaped specimen held by the electrostatic chuck device, the temperature distribution during processing is uniformly controlled so that the processing state of the plate-shaped specimen during plasma processing does not become uneven.

[0003] For example, as an electrostatic chuck device, an electrostatic chuck device having an electrostatic chuck member made of ceramic and a pedestal made of a metal matrix composite (MMC), which is a composite material of metal and ceramic, has been proposed (for example, refer to Patent Document 1). In Patent Document 1, an electrostatic chuck device has been realized that can easily transfer heat and can easily and uniformly control the temperature distribution of the plate-shaped specimen during processing by the characteristics of the MMC that constitutes the pedestal (base substrate).

[0004] In addition, as a pedestal of an electrostatic chuck device, a structure having a flow path inside through which a refrigerant flows is known (for example, refer to Patent Document 2). In the electrostatic chuck device having such a pedestal, by flowing a refrigerant through the pedestal, it is possible to appropriately cool the plate-shaped specimen adsorbed by the electrostatic chuck member.

[0005] Patent Document 1: Japanese Patent Laid-Open No. 11-163109

[0006] Patent Document 2: Japanese Patent Laid-Open No. 2020-167220

[0007] In recent years, with the diversification of semiconductor processes, the temperature of the plate-shaped specimen during processing is controlled within a wider temperature range than in the past. To achieve such temperature control, as a new type of pedestal, a pedestal made of MMC and having a flow path inside is being studied. However, compared with metals, MMC is difficult to machine and needs to be improved. Summary of the Invention

[0008] The present invention has been completed in view of these circumstances, and an object thereof is to provide a new type of pedestal made of MMC. And, an object is to provide a new type of electrostatic chuck device having such a pedestal. In addition, another object is to provide a method for manufacturing a pedestal that can easily manufacture such a pedestal.

[0009] To solve the above problems, one aspect of the present invention includes the following aspects.

[0010] [1]A base, comprising: a first component made of a metal matrix composite material; a second component made of a metal matrix composite material and overlapping the first component; and an adhesive layer made of an organic material and bonding the first component and the second component. The first component has a rib portion on a side facing the second component. The adhesive layer is sandwiched between the top surface of the rib portion and the surface of the second component facing the first component, and the space surrounded by the groove portion formed between adjacent rib portions and the second component is a flow path for refrigerant to flow.

[0011] [2]The base according to [1], wherein the adhesive layer is formed only at a position in contact with the top surface of the rib portion.

[0012] [3]The base according to [1] or [2], wherein the thickness of the adhesive layer is 30 μm or more and 300 μm or less.

[0013] [4]The base according to any one of [1] to [3], wherein the adhesive layer is located at a position lower than the upper end of the flow path.

[0014] [5]An electrostatic chuck device, comprising: an electrostatic chuck component made of a ceramic material; the base according to any one of [1] to [4]; and a bonding layer bonding the electrostatic chuck component and the base. When the whole electrostatic chuck component is set to 100% by volume, the electrostatic chuck component contains 50% by volume or more of alumina.

[0015] [6]The electrostatic chuck device according to [5], wherein the bonding layer contains a resin material and a thermally conductive filler, and the content of the thermally conductive filler in the bonding layer is 50% by mass or more and 80% by mass or less.

[0016] [7]A method for manufacturing a base, having: a forming process of forming a precursor in which a groove portion is formed in at least one of a pair of green sheets; a manufacturing process of manufacturing a sintered body obtained by firing the precursor and infiltrating metal, and a first component made of a metal matrix composite material and a second component made of a metal matrix composite material and overlapping the first component; and a bonding process of opposing the first component and the second component with the groove portion as the inside and bonding the first component and the second component with an organic sheet adhesive.

[0017] Advantages of the Invention

[0018] According to the present invention, a novel base made of MMC can be provided. Moreover, a novel electrostatic chuck device having such a base can be provided. In addition, a method for manufacturing a base that can easily manufacture such a base can be provided. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a schematic cross-sectional view showing the electrostatic chuck device 1A.

[0020] Figure 2 It is a process chart showing an example of the manufacturing method of the base 3A.

[0021] Figure 3 It is a process chart showing an example of the manufacturing method of the base 3A.

[0022] Figure 4 It is a process chart showing an example of the manufacturing method of the base 3A.

[0023] Figure 5 It is an explanatory view of the base according to the modified example.

[0024] Figure 6 It is an explanatory view of the base according to the modified example.

[0025] REFERENCE SIGNS LIST

[0026] 1A - Electrostatic chuck device, 2 - Electrostatic chuck member, 2a - Loading surface, 3A, 3B, 3C - Base, 3f - Flow path, 4 - Bonding layer, 31, 36 - First member, 31x, 36x, 37x, 301x - Groove portion, 32, 37 - Second member, 33, 35 - Adhesive layer, 300 - Green sheet, 311, 361, 371 - Rib portion, 311a, 361a, 371a - Top surface. DETAILED DESCRIPTION

[0027] [First Embodiment]

[0028] Hereinafter, with reference to Figure 1 , the base, the method for manufacturing the base, and the electrostatic chuck device according to the present embodiment will be described. In addition, in all the following drawings, in order to easily observe the drawings, the dimensions, ratios, etc. of each component are appropriately different.

[0029] 《Base, Electrostatic Chuck Device》

[0030] Figure 1 It is a schematic cross-sectional view showing the electrostatic chuck device 1A. The electrostatic chuck device 1A includes an electrostatic chuck member 2, a base 3A, a bonding layer 4, a support plate 5, an insulator (insertion part) 23, and a power supply terminal 16. The electrostatic chuck member 2 and the base 3A are laminated on each other via the bonding layer 4.

[0031] In this specification, the direction in which the stacked electrostatic chuck member 2 and the base 3A are stacked is referred to as the stacking direction. Further, the side on which the electrostatic chuck member 2 is disposed with respect to the base 3A is referred to as one side in the stacking direction, and the opposite side is referred to as the other side in the stacking direction. And, in the following description, each part of the electrostatic chuck device 1A is described with the vertical direction as the stacking direction. However, the vertical direction here is only a direction used for simplifying the description and does not limit the posture when using the electrostatic chuck device 1A. Further, the upper side corresponds to one side in the stacking direction, and the lower side corresponds to the other side in the stacking direction.

[0032] [Electrostatic chuck member]

[0033] The electrostatic chuck member 2 includes a dielectric substrate 11 and a suction electrode 13 located inside the dielectric substrate 11. A placement surface 2a for placing the suction wafer W is provided on the upper surface of the electrostatic chuck member 2. A focus ring for surrounding the wafer W can be disposed outside the placement surface 2a of the electrostatic chuck member 2.

[0034] The dielectric substrate 11 is made of a composite sintered body having sufficient mechanical strength and durability against corrosive gases and their plasmas. As the dielectric material constituting the dielectric substrate 11, ceramics having mechanical strength and durability against corrosive gases and their plasmas can be preferably used.

[0035] As the ceramics constituting the dielectric substrate 11, alumina (Al2O3) is included as the main component. "Main component" means more than 50% by volume of the whole. For example, an alumina (Al2O3) sintered body, an alumina (Al2O3)-silicon carbide (SiC) composite sintered body, etc. can be preferably used. In particular, from the viewpoints of dielectric characteristics at high temperatures, high corrosion resistance, plasma resistance, and heat resistance, the material constituting the dielectric substrate 11 is preferably an Al2O3-SiC composite sintered body.

[0036] The dielectric substrate 11 is in the shape of a circular plate when viewed from above. The dielectric substrate 11 has a placement surface 2a for placing the wafer W and a back surface 2b facing the opposite side of the placement surface 2a. For example, a plurality of protrusions (not shown) can be formed at a predetermined interval on the placement surface 2a. In this case, the placement surface 2a supports the wafer W at the front ends of the plurality of protrusions.

[0037] The suction electrode 13 is disposed inside the dielectric substrate 11. The suction electrode 13 extends in a plate shape along the placement surface 2a of the dielectric substrate 11. The suction electrode 13 generates an electrostatic suction force for holding the wafer W on the placement surface 2a of the dielectric substrate 11 by applying a voltage. A power supply terminal 16 for applying a DC voltage to the suction electrode 13 is connected to the suction electrode 13.

[0038] The adsorption electrode 13 is composed of a composite of an insulating material and a conductive material. The insulating material contained in the adsorption electrode 13 is not particularly limited. For example, it is preferably at least one selected from the group including aluminum oxide (Al2O3), aluminum nitride (AlN), silicon nitride (Si3N4), yttrium(III) oxide (Y2O3), yttrium aluminum garnet (YAG), and SmAlO3. The conductive material contained in the adsorption electrode 13 is preferably at least one selected from the group including molybdenum carbide (MO2C), molybdenum (Mo), tungsten carbide (WC), tungsten (W), tantalum carbide (TaC), tantalum (Ta), silicon carbide (SiC), carbon black, carbon nanotubes, and carbon nanofibers.

[0039] The thickness of the electrostatic chuck member 2 is preferably 0.5 mm or more and 5 mm or less. When the thickness of the electrostatic chuck member 2 is 0.5 mm or more, the withstand voltage of the electrostatic chuck member 2 becomes higher. And when the thickness of the electrostatic chuck member 2 is 5 mm or less, the heat capacity of the electrostatic chuck member 2 becomes smaller, so it is easy to keep the temperature of the plate-like specimen as the object to be processed uniform in plasma processing.

[0040] [Base]

[0041] The base 3A supports the electrostatic chuck member 2 from below. The base 3A has an upper support surface 3a facing upward and a lower surface 3b facing downward. The support surface 3a faces the back surface 2b of the dielectric substrate 11 in the vertical direction with the bonding layer 4 interposed therebetween. In the base 3A, the electrostatic chuck member 2 is supported on the support surface 3a.

[0042] A flow path 3f for allowing a refrigerant to flow and circulate is provided inside the base 3A. As the refrigerant flowing through the flow path 3f, water, He gas, N2 gas, etc. can be used. The flow path 3f extends along the support surface 3a. The refrigerant in the flow path 3f cools the entire base 3A and cools the electrostatic chuck member 2 via the support surface 3a.

[0043] The base 3A is a member having a disc shape in a plan view and is made of a material having a thermal conductivity of 140 W / m·K or more. In this specification, "plan view" means a view field observed from the thickness direction of the electrostatic chuck member 2.

[0044] The base 3A has a first member 31, a second member 32, and an adhesive layer 33. The first member 31 and the second member 32 are bonded via the adhesive layer 33. That is, with respect to the first member 31 and the second member 32, the two are bonded by the adhesive layer 33, and thus are integrated via the adhesive layer 33.

[0045] (First member, second member)

[0046] The first component 31 is a component that is disc-shaped when viewed from above, and has a rib portion 311 on the side facing the second component 32. A groove portion 31x is formed between adjacent rib portions 311.

[0047] The second component 32 is a component that is disc-shaped when viewed from above. The contour of the second component 32 overlaps (coincides) with the contour of the first component 31 when viewed from above.

[0048] The space surrounded by the groove portion 31x and the second component 32 corresponds to the flow path 3f.

[0049] The first component 31 and the second component 32 can use a known metal matrix composite (Metal Matrix Composite, hereinafter, MMC) as the material. After adjusting the porous ceramic substrate, MMC can be adjusted by a known method (metal infiltration method, forging method) of introducing metal into the pores of the ceramic substrate.

[0050] The material forming the first component 31 and the material forming the second component 32 may be different, but preferably the same material. "The same material" means that the materials constituting the MMC, that is, the material of the ceramic substrate and the metal introduced into the pores are the same. When the material forming the first component 31 and the material forming the second component 32 are the same material, it is more preferable that the ratio of the metal introduced into the ceramic substrate is also the same.

[0051] More specifically, the MMC as the material of the first component 31 and the second component 32 preferably contains SiC as the material. Specifically, when the whole of the first component 31 and the second component 32 is set to 100% by volume, the above MMC contains 75% by volume or more and less than 100% by volume of SiC, preferably contains 75% by volume or more and 99% by volume or less of SiC.

[0052] As the metal introduced into the pores, the above MMC contains one or more elements selected from the group including aluminum (Al), silicon (Si), and magnesium (Mg). By including these elements in SiC, the thermal conductivity of the base 3A is increased, and heat dissipation via the base 3A is facilitated. In the MMC containing 75% by volume or more of SiC, by adjusting the compounding materials contained in the material, the coefficient of thermal expansion can be controlled within the range of 2.8×10 -6 / K to 6.8×10 -6 / K.

[0053] The absolute value of the difference in the coefficient of thermal expansion between the above-mentioned MMC and the ceramic material used as the material of the electrostatic chuck member 2 is 10 ppm / K or less, preferably 7.0 ppm / K or less. By having the above relationship between the material of the base 3A and the material of the electrostatic chuck member 2, internal stress caused by thermal deformation during heating can be easily suppressed.

[0054] When the entire MMC is set to 100% by volume, the above-mentioned MMC contains 75% by volume or more and 99% by volume or less of SiC, and is preferably a material containing 1% by volume or more and 25% by volume or less of Al, Si, or Mg. The coefficient of thermal expansion of the base 3A formed of MMC with this composition is very close to that of Al2O3 - SiC constituting the electrostatic chuck member 2, and the difference in the amount of thermal expansion from the electrostatic chuck member 2 during heating becomes smaller.

[0055] For example, Mg - SiC (7.0 ppm / K), Al - SiC (6.8 ppm / K), and Si - SiC (2.8 ppm / K) can be used as the MMC. The amount of metal contained in each MMC can be appropriately adjusted within the above-mentioned content rate range according to the desired coefficient of thermal expansion.

[0056] (Adhesive layer)

[0057] The adhesive layer 33 is made of an organic material. The adhesive layer 33 is provided on the entire surface of one surface 32a of the second member 32, and is sandwiched between the top surface 311a of the rib portion 311 and the surface (one surface 32a) of the second member 32 facing the first member 31.

[0058] Examples of the material of the adhesive layer 33 include silicone resins, acrylic resins, epoxy resins, and polyimide resins.

[0059] The thickness of the adhesive layer 33 is preferably 30 μm or more and 300 μm or less, more preferably 75 μm or more and 150 μm or less, and further preferably 75 μm or more and 120 μm or less.

[0060] And, in Figure 1 the adhesive layer 33 is located at a position lower than the upper end of the flow path 3f. In this structure, since there is no adhesive layer 33 between the placement surface 2a and the flow path 3f, heat transfer is not easily blocked by the adhesive layer 33 formed of an organic material.

[0061] The adhesive layer 33 can be formed by applying a paste adhesive to one surface of the second member 32 and curing it, or by disposing a sheet adhesive between the first member 31 and the second member 32 and curing it.

[0062] When the first component 31 and the second component 32 are made of a metal material, as a method of connecting and integrating the two, Si bonding or silver solder bonding can be considered. However, as a result of research by the inventors and the like, when integrating components made of MMC with each other, the following problems were unexpectedly found when using these methods.

[0063] First, in the case of performing Si bonding, as a result of Si bonding the first component 31 and the second component 32 made of Si-SiC (MMC), it was confirmed that there were sites where Si contained in the MMC was ejected inside the formed 3f. This is considered because the metal that penetrated into the MMC was melted by heating during Si bonding. If Si is ejected into the flow path 3f, it may block the flow path 3f. And even if it does not cause blockage of the flow path 3f, the cross-sectional area of the flow path 3f will decrease and a pressure loss will occur, resulting in a decrease in the performance of the base 3A.

[0064] The above problems are not limited to the case where the MMC is Si-SiC, and the same may occur even in the case of Al-SiC or Mg-SiC in which Al or Mg with a lower melting point than Si penetrates inside.

[0065] And, in the case of performing silver solder bonding, Si contained in the MMC diffuses from the bonding surface into the silver solder to form an Ag-Si alloy. As a result, the bonding strength between the first component 31 and the second component 32 decreases, and the reliability of the base 3A may decrease.

[0066] The above problems are not limited to the case where the MMC is Si-SiC, and the same may occur even in the case of Al-SiC or Mg-SiC.

[0067] Based on the above insights, in the base 3A of the present embodiment, the first component 31 and the second component 32 are bonded and integrated by a bonding layer 33 made of an organic material as a forming material. When curing the adhesive, even if heating is required, the reaction temperature of the adhesive (for example, 130 °C) is lower than the heating temperature during Si bonding, and the ejection of the metal in the MMC can be suppressed. And the metal in the MMC does not diffuse into the bonding layer 33 of the organic material either.

[0068] The manufacturing method of such a base will be described later.

[0069] The surface of the base 3A is preferably covered with a metal film. As the metal film, for example, an Al spray coating film can be used. The film thickness of the metal film can be set to, for example, 100 μm or more and 300 μm or less. Thereby, the base 3A can be used as an internal electrode for plasma generation. The base 3A is connected to an external high-frequency power supply 22 via a matcher (not shown).

[0070] The base 3A is provided with a hole portion 3h. The hole portion 3h extends in the vertical direction. The hole portion 3h penetrates the base 3A in the vertical direction and opens at the support surface 3a and the lower surface 3b of the base 3A, respectively. The hole portion 3h is, for example, circular in a plan view. An insulator 23 to be described later is inserted into the hole portion 3h.

[0071] (Bonding layer)

[0072] The bonding layer 4 is interposed between the electrostatic chuck member 2 and the base 3A to bond the electrostatic chuck member 2 and the base 3A. The bonding layer 4 is preferably a layer made of a mixture containing a resin material and a heat-conductive filler (hereinafter simply referred to as a filler).

[0073] (Bonding layer)

[0074] The bonding layer 4 is sandwiched between the electrostatic chuck member 2 and the base 3A and bonds the electrostatic chuck member 2 and the base 3A. The bonding layer 4 contains a resin material and a heat-conductive filler (hereinafter simply referred to as a filler).

[0075] The bonding layer 4 containing the resin material is relatively more deformable than the electrostatic chuck member 2 and the base 3A. Therefore, compared with a joint layer formed by brazing, the bonding layer 4 is more likely to deform accordingly when the electrostatic chuck member 2 and the base 3A expand or contract due to temperature changes. And, for example, even if there is a difference in the thermal expansion amount between the electrostatic chuck member 2 and the base 3A, internal stress caused by the difference in thermal expansion amount can be suppressed by the deformation of the bonding layer 4.

[0076] As the resin, as long as it is not likely to cause cohesive failure due to thermal stress, there is no particular limitation, and examples thereof include silicone resin, acrylic resin, epoxy resin, phenolic resin, polyurethane resin, unsaturated polyester resin, etc. Among these, from the viewpoint of high elongation and being less likely to cause cohesive failure due to changes in thermal stress, silicone resin is preferred.

[0077] The filler has a function of increasing the thermal conductivity coefficient in the thickness direction of the bonding layer 4. For this function, as the filler, one or more selected from the group including inorganic oxides, inorganic nitrides, and inorganic oxynitrides can be cited. For example, it is preferable that the filler contains surface-coated aluminum nitride (AlN) particles in which a coating layer made of silicon oxide (SiO2) or aluminum oxide (Al2O3) is formed on the surface of aluminum nitride (AlN) particles.

[0078] The content rate of the filler in the bonding layer 4 is 50% by mass or more and 80% by mass or less. The content rate of the filler is more preferably 55% by mass or more, and preferably 60% by mass or more. Also, the content rate of the filler is preferably 75% by mass or less, and more preferably 70% by mass or less. The upper limit value and the lower limit value of the content rate of the filler can be arbitrarily combined.

[0079] As long as the content rate of the filler is at least the lower limit value, sufficient thermal conductivity can be imparted to the bonding layer 4, and the transfer of heat from the electrostatic chuck member 2 to the base 3A can be promoted. As long as the content rate of the filler is at most the upper limit value, it is easy to deform accordingly when the electrostatic chuck member 2 and the base 3A expand or contract due to temperature changes.

[0080] In the case of using a bonding layer containing a resin material, in a well-known electrostatic chuck device, Al is used as the material of the base. Compared with the base made of Al and the electrostatic chuck member made of ceramic, the coefficient of thermal expansion is larger, and it significantly deforms when heated. Therefore, when the electrostatic chuck member and the base thermally expand in the plasma process, the difference in the amount of thermal expansion between the electrostatic chuck member and the base is large, and there is a possibility that the bonding layer containing the resin material breaks. However, since the base 3A of the present embodiment uses MMC as the material, the difference in the amount of thermal expansion from the electrostatic chuck member 2 can be reduced, and the breakage of the bonding layer can be suppressed.

[0081] In addition, in the electrostatic chuck device 1A of the present embodiment, by using the base 3A made of MMC, compared with the electrostatic chuck device using an Al base, the amount of deformation required for the bonding layer for absorbing the thermal expansion of the electrostatic chuck member 2 and the base 3A can be smaller. Therefore, compared with the electrostatic chuck device using an Al base, the amount of filler contained in the bonding layer can be increased to 50% by mass or more and 80% by mass or less, and the thermal conductivity of the bonding layer can be further improved.

[0082] If there are more fillers contained in the bonding layer 4, the fillers are likely to aggregate when the resin material (adhesive) before curing is kneaded with the fillers, and it is difficult for the fillers to disperse in the resin. In order to promote the dispersion of the fillers during kneading, the fillers are preferably spherical rather than plate-shaped or fibrous.

[0083] Also, in order to promote the dispersion of the fillers during kneading, it is preferable that the fillers have a bimodal particle size distribution.

[0084] The shape of the fillers and the bimodality of the particle size distribution of the fillers can be confirmed by the following method.

[0085] First, the electrostatic chuck member 2 or the base 3A is peeled off from the electrostatic chuck device 1A to expose the bonding layer 4, and the surface of the exposed bonding layer 4 is ion milled to be flattened. An SEM image of the obtained cross section is taken, and the particle size of each of the plurality of fillers contained in the obtained image is measured by image analysis. Regarding the particle size of the fillers, it can be analyzed and obtained by the image analysis software attached to the SEM.

[0086] The magnification of the SEM image is not limited as long as it can measure the particle size of the fillers contained in the bonding layer 4, but a magnification that includes at least 200 fillers in one field of view of the SEM image is sufficient. The magnification of the SEM image can be, for example, from 100 times to 5000 times.

[0087] Confirm the shape (plate-like, fibrous, spherical) of the fillers contained in the SEM image from the obtained measurement values.

[0088] And, based on the obtained measurement values, the particle size distribution of the fillers contained in the SEM image is obtained, and it is confirmed whether it is a bimodal particle size distribution.

[0089] In the present embodiment, for the filler to be "bimodal" means that in the particle size distribution obtained by the above method, there are two or more maxima, preferably two. In addition, for the case where the filler used as the material of the electrostatic chuck device 1A is bimodal, in addition to the above method, it is also possible to measure the particle size distribution of the filler by a known laser diffraction scattering method for judgment.

[0090] The average particle size of the heat-conductive fillers contained in the bonding layer 4 is preferably 1 / 2 or less of the thickness of the bonding layer 4, more preferably 1 / 2000 or more and 1 / 2 or less. When the average particle size of the heat-conductive fillers is 1 μm or more and 100 μm or less, it is preferable that the thickness of the bonding layer 4 is 2 μm or more and 200 μm or less. By setting the thickness of the bonding layer 4 in this way, it is easy to form the bonding layer 4 containing the fillers into a uniform thickness, and uneven cooling (improvement of thermal uniformity) can be reduced.

[0091] The average particle size of the fillers can be obtained from the above-mentioned SEM image by image analysis.

[0092] The thermal conductivity of such a bonding layer 4 is preferably 0.3 W / mK or more, more preferably 1.0 W / mK or more. When the bonding layer 4 has such a thermal conductivity, heat can be appropriately transferred from the electrostatic chuck member 2 to the base 3A, and the entire device can be appropriately cooled.

[0093] Further, regarding the bonding layer 4, the elastic modulus at 25°C is preferably 10,000 MPa or less, more preferably 1,000 MPa or less. When the electrostatic chuck device 1A is repeatedly heated and cooled in the plasma process, the bonding layer 4 may experience interfacial peeling due to internal stress caused by the thermal expansion difference between the electrostatic chuck member 2 and the base 3A. In contrast, if the bonding layer 4 has the above elastic modulus, the bonding layer 4 can relieve the above internal stress and suppress peeling.

[0094] The above thermal conductivity and elastic modulus can be controlled by adjusting the addition amount of the filler. Tables 1 to 2 below show the thermal conductivity, elastic modulus when each filler is added to the silicone resin, and whether there is peeling after bonding of the MMC base (82 vol% SiC, 18 vol% Si) / ceramic material (Al2O3 - SiC).

[0095] [Table 1]

[0096]

[0097] [Table 2]

[0098]

[0099] The bonding layer 4 can be formed by clamping a liquid adhesive between the electrostatic chuck member 2 and the base 3A and curing it, or by clamping a sheet-like or film-like adhesive between the electrostatic chuck member 2 and the base 3A.

[0100] When the material of the bonding layer 4 is a liquid adhesive, the viscosity of the adhesive is preferably 500 Pa·s or less.

[0101] As described above, if the amount of filler contained in the bonding layer 4 increases, the adhesive force between the bonding layer 4 and the base 3A tends to decrease. Therefore, a primer layer is preferably formed on the surface of the base 3A that contacts the bonding layer 4.

[0102] The primer layer uses an organosilicon compound having a functional group and an alkoxy group that react with the resin material (adhesive) used as the material of the bonding layer 4. As the functional group, epoxy group, vinyl group, methacrylic group, and mercapto group can be exemplified. Further, the above organosilicon compound has one or more alkoxy groups. In addition, the organosilicon compound can be a single molecule or a polymer. As such an organosilicon compound, known compounds used as the material of the primer layer can be used.

[0103] This silicone compound is applied to the surface of the base 3A, and the alkoxy groups of the silicone compound react with the surface of the base 3A to form bonds. Also, the functional groups of the silicone compound react with the adhesive to form bonds. Thus, when a primer layer is formed, a higher adhesive force is generated between the bonding layer 4 and the base 3A compared to the case without a primer layer.

[0104] Also, the bonding layer 4 can be a layer formed of a metallic material.

[0105] Regarding the bonding layer 4, when the entire bonding layer 4 is set to 100% by volume, an alloy containing 50% by volume or more of Al or Ag and containing 0.02% by volume or more and 40% by volume or less of at least one metal selected from the group consisting of Ti, Zr, and Hf is used as the forming material. By the bonding layer 4 containing at least one metal selected from the group consisting of Ti, Zr, and Hf, when the electrostatic chuck member 2 is joined to the base 3A, the molten alloy obtained by melting the material of the bonding layer 4 easily wets and spreads on the surface of the ceramic (electrostatic chuck member 2), facilitating joining. Also, by the bonding layer 4 containing the above metals, the above metals easily adhere closely to the ceramic (electrostatic chuck member 2), suppressing the generation of voids at the interface and enabling firm joining.

[0106] The thickness of the bonding layer 4 is preferably 0.005 mm or more and 0.5 mm or less.

[0107] When manufacturing the electrostatic chuck device 1A, as the material of the bonding layer 4, a metal foil can be used, or a metal paste obtained by adding an adhesive to metal powder can be used. These materials are disposed between the electrostatic chuck member 2 and the base 3A and heated to a temperature above the melting point of the metallic material forming the bonding layer. By the molten metallic material wetting and spreading between the electrostatic chuck member 2 and the base 3A, the bonding layer 4 can be formed.

[0108] (Support plate)

[0109] The support plate 5 supports the base 3A from the lower surface 3b of the base 3A. Also, the support plate 5 has a hole 5h through which the insulator 23 is inserted. The support plate 5 is made of a material having a Young's modulus higher than that of the base 3A. For example, any of metal, MMC, and ceramic can be used as the material of the support plate 5. Among them, as the support plate 5, it is preferable to use a ceramic plate such as Al2O3 having a Young's modulus higher than that of the base 3A.

[0110] The ceramic used in the support plate 5 is preferably the same as the material used in the electrostatic chuck member 2. As specific ceramics, alumina or aluminum nitride can be cited. By using the same material in the support plate 5 and the electrostatic chuck member 2, the difference in the coefficient of thermal expansion between the support plate 5 and the electrostatic chuck member 2 can be reduced, and warping of the electrostatic chuck device 1A can be suppressed.

[0111] (Insulator)

[0112] The insulator 23 is inserted into the hole portions 3h and 5h and assembled to the base 3A. That is, the insulator 23 functions as an insertion part inserted into the hole portions 3h and 5h. The insulator 23 is a cylindrical shape extending in the vertical direction (lamination direction). A power supply terminal 16 is disposed in the through hole 23h of the insulator 23. The outer peripheral surface of the insulator 23 is joined to the inner side surfaces of the hole portions 3h and 5h by joining means such as adhesion. The insulator 23 insulates the base 3A made of metal from the power supply terminal 16.

[0113] The insulator 23 uses, for example, ceramic as a forming material. That is, the insulator 23 is composed of an insulating member. Thereby, the insulator 23 can suppress the gas introduction hole from becoming a starting point of abnormal discharge. The insulator 23 has durability against plasma. As the ceramic constituting the insulator 23, one or more ceramics selected from AlN, Al2O3, Si3N4, zirconia (ZrO2), silicon aluminum oxynitride (SiAlON), boron nitride (BN), and SiC can be adopted.

[0114] The end surface on the upper side (one side in the lamination direction) of the insulator 23 (hereinafter, the upper end surface 23a) abuts on the electrostatic chuck member 2 or is disposed adjacent to the electrostatic chuck member 2 with an insulating adhesive interposed therebetween.

[0115] (Power supply terminal)

[0116] The power supply terminal 16 extends downward from the adsorption electrode 13. The power supply terminal 16 is connected to an external power supply 21. The power supply 21 applies a voltage to the adsorption electrode 13. The number, shape, etc. of the power supply terminals 16 are determined according to the form of the adsorption electrode 13, that is, according to the monopolar type or the bipolar type.

[0117] The power supply terminal 16 is inserted through a hole 11h provided in the lower part of the dielectric substrate 11 and reaching the adsorption electrode 13 and the through hole 23h of the insulator 23.

[0118] The hole 11h and the through hole 23h are circular when viewed from the lamination direction and communicate with each other. The inner diameters of the hole 11h and the through hole 23h are slightly larger than the outer diameter of the power supply terminal 16.

[0119] According to the base configured as described above, a new base using MMC as a material can be manufactured.

[0120] In addition, the electrostatic chuck device configured as described above can provide a novel electrostatic chuck device using a base made of MMC.

[0121] "Method for Manufacturing Base"

[0122] Figures 2 to 4 It is a process diagram showing an example of the manufacturing method of the base 3A, and is a cross-sectional view in the same field of view as Figure 1 the same.

[0123] First, SiC powder, a binder, a plasticizer, etc. are mixed at a predetermined ratio to form a slurry, and the slurry is coated and dried to form a pair of green sheets of SiC. The green sheets can use commercially available products.

[0124] Next, as Figure 2 shown, a pair of green sheets 300 are processed to form a first precursor 301 that is a precursor of the first component and a second precursor 302 that is a precursor of the second component (process of forming precursors). Specifically, at least one of the pair of green sheets 300 is processed, and a groove portion 301x is formed on one surface 301a. In addition, a through hole 301h that penetrates in the thickness direction is formed in the green sheet 300 to obtain the first precursor 301.

[0125] And, a through hole 302h that penetrates in the thickness direction is formed in the other green sheet 300 to obtain the second precursor 302.

[0126] Next, as Figure 3 shown, the first component 31 is manufactured from the first precursor 301, and the second component 32 is manufactured from the second precursor 302 (process of manufacturing the first component and the second component).

[0127] Specifically, the first component 31 is manufactured by firing the first precursor 301 and infiltrating a metal (Si, Al, or Mg) by a known metal infiltration method. The groove portion 301x of the first precursor 301 maintains its shape and becomes the groove portion 31x of the first component 31. Similarly, the through hole 301h becomes the through hole 31h of the first component 31. A rib portion 311 that protrudes relative to the groove portion 31x is formed in the first component 31.

[0128] Similarly, the second component 32 is manufactured by calcining the second precursor 302 and infiltrating a metal by a known metal infiltration method. The through hole 302h of the second precursor 302 becomes the through hole 32h of the second component 32.

[0129] Next, as Figure 4As shown, the first component 31 is bonded to the second component 32 (bonding process). Specifically, with the groove portion 31x of the first component 31 on the inner side, the first component 31 and the second component 32 are opposed to each other, and they are bonded with an adhesive. Thus, the top surface 311a of the rib portion 311 is bonded to one surface 32a of the second component 32 (the surface opposing the first component 31). The adhesive cures to form the bonding layer 33. The bonding layer 33 is sandwiched between the top surface 311a and the one surface 32a.

[0130] As the adhesive, a paste-like or gel-like adhesive with fluidity can be used, or a sheet-like adhesive can also be used. Since extrusion is easily suppressed and processing is easy, it is preferably to use a sheet-like adhesive.

[0131] The space surrounded by the groove portion 31x and one surface 32a of the second component 32 (the bonding layer 33 formed on the one surface 32a) becomes the flow path 3f.

[0132] In the bonding layer 33, a through hole 33h that overlaps with the through hole 31h of the first component 31 and the through hole 32h of the second component 32 in a plane is formed. By curing the adhesive, a hole portion 3h that connects the through hole 31h, the through hole 32h, and the through hole 33h is obtained.

[0133] According to the manufacturing method of the base constituted as described above, since the green sheet is used as the starting material, it is possible to easily manufacture a base made of MMC that is difficult to process. And by using an organic material (organic adhesive) when bonding the first component 31 and the second component 32, it is possible to preferably integrate the two to manufacture the base 3A.

[0134] (Variant example)

[0135] In addition, in the present embodiment, on the base 3A, the bonding layer 33 is provided on the entire surface of one surface 32a of the second component 32, but it is not limited thereto.

[0136] Figure 5 、 Figure 6 is an explanatory diagram of the base according to the variant example, and is a diagram corresponding to Figure 4 corresponding.

[0137] Figure 5 The base 3B shown has a first component 31, a second component 32, and a bonding layer 35. The bonding layer 35 has a through hole 35h that overlaps with the hole portion 3h, and has a through hole 35x that overlaps with the groove portion 31x of the first component 31. That is, in the base 3B, the bonding layer 35 is only formed at the position in contact with the top surface 311a of the rib portion 311.

[0138] In this base 3B, a flow path 3f is formed by a space surrounded by the groove portion 31x, one surface 32a of the second member 32, and the through hole 35x.

[0139] Figure 6 The shown base 3C has a first member 36, a second member 37, and an adhesive layer 35.

[0140] The first member 36 is a member having a disk shape in a plan view. The first member 36 has a rib portion 361 on the side facing the second member 37, and has a through hole 36h penetrating the first member 36 in the thickness direction. In the first member 36, a groove portion 36x is formed between adjacent rib portions 361.

[0141] The second member 37 is a member having a disk shape in a plan view. The outline of the second member 37 overlaps the outline of the first member 36 in a plan view. The second member 37 has a rib portion 371 on the side facing the first member 36, and has a through hole 37h penetrating the second member 37 in the thickness direction. In the second member 37, a groove portion 37x is formed between adjacent rib portions 371.

[0142] The first member 36 and the second member 37 can be manufactured by the same method as the method for manufacturing the above-described first member 31.

[0143] In the base 3C, the adhesive layer 35 is formed only at a position in contact with the top surface 361a of the rib portion 361. Thus, the adhesive layer 35 is sandwiched between the top surface 361a of the rib portion 361 and the top surface 371a of the rib portion 371.

[0144] In the base 3C, a space surrounded by the groove portion 36x, the groove portion 37x, and the through hole 35x forms a flow path 3f. And, the through hole 36h, the through hole 37h, and the through hole 35h are communicated to form a hole portion 3h.

[0145] The adhesive layer 35 provided in the base 3B and the base 3C can be formed by the same method as the adhesive layer 33.

[0146] This base 3B or base 3C can be used as a base provided in an electrostatic chuck device by replacing Figure 1 the base 3A provided in the shown electrostatic chuck device 1A.

[0147] The base 3B and the base 3C are new bases using MMC as a material. And, compared with the base 3A, the area of the adhesive layer exposed on the inner surface of the flow path 3f in the base 3B and the base 3C is smaller. Therefore, in the electrostatic chuck device having the base 3B and the base 3C, heat transfer is not easily hindered by the adhesive layer, and heat transferred from the mounting surface can be preferably removed, and uniformization of the temperature distribution of the mounting surface can be achieved.

[0148] As described above, with reference to the accompanying drawings, preferred embodiments of the present invention have been described. However, the present invention is not limited to this example. The shapes or combinations of the respective components shown in the above examples are merely examples, and various modifications can be made according to design requirements and the like without departing from the gist of the present invention.

Claims

1. A abutment, characterized in that, Comprising: A first component made of a metal matrix composite material; A second component made of a metal matrix composite material and overlapping the first component; and An adhesive layer made of an organic material and bonding the first component and the second component, The first component has a rib portion on a side facing the second component, The adhesive layer is sandwiched between the top surface of the rib portion and the surface of the second component facing the first component, The space surrounded by the groove portion formed between adjacent rib portions and the second component is a flow path for refrigerant to flow.

2. The base according to claim 1, wherein: The adhesive layer is formed only at positions in contact with the top surface of the rib portion.

3. The base according to claim 1 or 2, wherein: The thickness of the adhesive layer is 30 μm or more and 300 μm or less.

4. The base according to claim 1 or 2, wherein: The adhesive layer is located at a position lower than the upper end of the flow path.

5. An electrostatic chuck device, characterized in that, Comprising: An electrostatic chuck component made of a ceramic material; The base according to claim 1 or 2; and A bonding layer bonding the electrostatic chuck component and the base, When the entire electrostatic chuck component is set to 100% by volume, the electrostatic chuck component contains 50% by volume or more of alumina.

6. The electrostatic chuck device according to claim 5, wherein: The bonding layer contains a resin material and a thermally conductive filler, The content rate of the thermally conductive filler in the bonding layer is 50% by mass or more and 80% by mass or less.

7. A manufacturing method of an abutment, characterized in that Having: A forming process for forming a precursor in which a groove portion is formed in at least one of a pair of green sheets; A manufacturing process for manufacturing a sintered body obtained by firing the precursor into which metal has penetrated and having a first component made of a metal matrix composite material and a second component made of a metal matrix composite material and overlapping the first component; And A bonding process in which the first component and the second component are opposed with the groove portion as the inner side and the first component and the second component are bonded with an organic sheet adhesive.

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