Base, electrostatic chuck device, and method for manufacturing base

Abstract

To provide a novel base made of MMC, provide a novel electrostatic chuck device having such a base, and provide a method for manufacturing the base that enables easy production of such a base.SOLUTION: A base comprises: a first member made of a metal group composite material; a second member made of a metal group composite material and overlapping the first member; and an adhesive layer made of an organic material and bonding the first member and the second member together. The first member has a projection portion on a side facing the second member, and the adhesive layer is sandwiched between a top surface of the projection portion and a surface of the second member facing the first member. A space between a groove portion formed between the adjacent projection portions and the second member is a flow path through which a refrigerant flows.SELECTED DRAWING: Figure 1

Description

Technical Field

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

Background Art

[0002] Conventionally, in a semiconductor manufacturing process for manufacturing semiconductors such as ICs, LSIs, and VLSIs, when plasma-treating a plate-shaped sample such as a silicon wafer, an electrostatic chuck device that electrostatically adsorbs the plate-shaped sample has been used. The temperature distribution during processing is controlled uniformly so that unevenness does not occur in the processing state of the plate-shaped sample in plasma processing.

[0003] For example, as an electrostatic chuck device, an electrostatic chuck device having an electrostatic chuck member made of ceramics and a base made of a metal matrix composite (MMC), which is a composite material of metal and ceramics, has been proposed (see, for example, Patent Document 1). In Patent Document 1, an electrostatic chuck device that easily conducts heat and easily controls the temperature distribution of the plate-shaped sample during processing is realized due to the characteristics of the MMC that constitutes the base (base substrate).

[0004] In addition, as a base of an electrostatic chuck device, a configuration having a flow path for flowing a refrigerant inside is known (see, for example, Patent Document 2). In an electrostatic chuck device having a base with such a configuration, by flowing a refrigerant through the base, it becomes possible to suitably cool the plate-shaped sample adsorbed by the electrostatic chuck member.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0006] In recent years, with the diversification of semiconductor processes, the temperature of plate-shaped samples during processing has been controlled in a wider temperature range than before. To achieve such temperature control, a base made of MMC with internal flow paths has been considered as a new base material. However, MMC is more difficult to process than metal and improvement has been demanded.

[0007] The present invention has been made in view of such circumstances, and an object thereof is to provide a novel base made of MMC. Another object is to provide a novel electrostatic chuck device having such a base. A further object is to provide a method for manufacturing a base that enables such a base to be easily manufactured.

Means for Solving the Problems

[0008] To solve the above problems, one aspect of the present invention includes the following aspects.

[0009] [1] A first member made of a metal matrix composite material, a second member made of a metal matrix composite material and overlapping the first member, and an adhesive layer made of an organic material and bonding the first member and the second member, wherein the first member has a rib portion on a side facing the second member, and the adhesive layer is sandwiched between a top surface of the rib portion and a surface of the second member facing the first member, and a groove portion formed between adjacent rib portions and a space surrounded by the second member is a flow path for flowing a refrigerant.

[0010] [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.

[0011] [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.

[0012] [4] The base according to any one of [1] to [3], wherein the adhesive layer is located below the upper end of the flow path.

[0013] [5] An electrostatic chuck device comprising an electrostatic chuck member made of a ceramic material, a base according to any one of [1] to [4], and a bonding layer that bonds the electrostatic chuck member and the base, wherein the electrostatic chuck member contains 50% by volume or more of aluminum oxide when the total volume of the electrostatic chuck member is 100% by volume.

[0014] [6] The electrostatic chuck device according to [5], wherein the bonding layer includes a resin material and a thermally conductive filler, and the content of the thermally conductive filler in the adhesive layer is 50% by mass or more and 80% by mass or less.

[0015] [7] A method for manufacturing a base, comprising: forming a precursor in which at least one of a pair of green sheets has a groove formed therein; infiltrating a metal into a sintered body obtained by firing the precursor to produce a first member made of a metal matrix composite material and a second member made of a metal matrix composite material and overlapping the first member; and bonding the first member and the second member with an organic sheet adhesive with the groove inside and the first member and the second member facing each other.

Advantages of the Invention

[0016] According to the present invention, a novel base made of MMC can be provided. Further, a novel electrostatic chuck device having such a base can be provided. Furthermore, a method for manufacturing a base that enables such a base to be easily manufactured can be provided.

Brief Description of the Drawings

[0017]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

BEST MODE FOR CARRYING OUT THE INVENTION

[0018] [First Embodiment] Hereinafter, with reference to FIG. 1, the base, the method for manufacturing the base, and the electrostatic chuck device according to the present embodiment will be described. In all the following drawings, for the sake of easy viewing of the drawings, the dimensions, ratios, etc. of each component are appropriately different.

[0019] 《Base, Electrostatic Chuck Device》 FIG. 1 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, a dielectric (inserted 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.

[0020] In this specification, the direction in which the electrostatic chuck member 2 and the base 3A are laminated is referred to as the lamination 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 lamination direction, and the opposite side is referred to as the other side. In the following description, each part of the electrostatic chuck device 1A will be described with the vertical direction as the lamination direction. However, the vertical direction here is merely a direction used for simplification of the description and does not limit the posture of the electrostatic chuck device 1A during use. Note that the upper side corresponds to one side in the lamination direction, and the lower side corresponds to the other side in the lamination direction.

[0021] [Electrostatic Chuck Member] The electrostatic chuck member 2 has a dielectric substrate 11 and a suction electrode 13 located inside the dielectric substrate 11. On the upper surface of the electrostatic chuck member 2, a placement surface 2a for sucking the wafer W is provided. A focus ring surrounding the wafer W may be arranged outside the placement surface 2a of the electrostatic chuck member 2.

[0022] 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 are preferably used.

[0023] The ceramics constituting the dielectric substrate 11 contain aluminum oxide (Al2O3) as a main component. "Main component" means occupying 50% by volume or more of the whole. For example, an aluminum oxide (Al2O3) sintered body, an aluminum oxide (Al2O3)-silicon carbide (SiC) composite sintered body, etc. are preferably used. In particular, from the viewpoints of dielectric properties at high temperatures, high corrosion resistance, plasma resistance, and heat resistance, the material constituting the dielectric substrate 11 is preferably an Al2O3-SiC composite sintered body.

[0024] The dielectric substrate 11 is circular and plate-shaped in plan view. The dielectric substrate 11 has a placement surface 2a on which the wafer W is placed and a back surface 2b facing the opposite side of the placement surface 2a. On the placement surface 2a, for example, a plurality of protrusions (not shown) may be formed at predetermined intervals. In this case, the placement surface 2a supports the wafer W at the tip portions of the plurality of protrusions.

[0025] The suction electrode 13 is arranged inside the dielectric substrate 11. The suction electrode 13 extends in a plate shape along the placement surface 2a of the dielectric substrate 11. When a voltage is applied to the suction electrode 13, an electrostatic suction force for holding the wafer W on the placement surface 2a of the dielectric substrate 11 is generated. A power supply terminal 16 for applying a DC voltage to the suction electrode 13 is connected to the suction electrode 13.

[0026] The suction electrode 13 is composed of a composite of an insulating material and a conductive material. The insulating material contained in the suction electrode 13 is not particularly limited, but for example, it is preferably at least one selected from the group consisting of 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 suction electrode 13 is preferably at least one selected from the group consisting of 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.

[0027] 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 high. Also, when the thickness of the electrostatic chuck member 2 is 5 mm or less, the heat capacity of the electrostatic chuck member 2 becomes small, so it becomes easier to keep the temperature of the plate-shaped sample, which is the object to be processed, uniform during plasma processing.

[0028] [Base] The base 3A supports the electrostatic chuck member 2 from below. The base 3A has a 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 via the bonding layer 4. The base 3A supports the electrostatic chuck member 2 on the support surface 3a.

[0029] Inside the base 3A, a flow path 3f for flowing and circulating a refrigerant is provided. As the refrigerant flowing through the flow path 3f, water, He gas, N2 gas, etc. are adopted. The flow path 3f extends along the support surface 3a. The refrigerant in the flow path 3f cools the entire base 3A and also cools the electrostatic chuck member 2 via the support surface 3a.

[0030] The base 3A is a disc-shaped member in plan view and is made of a material having a thermal conductivity of 140 W / m·K or more. In this specification, "plan view" refers to the view seen from the thickness direction of the electrostatic chuck member 2.

[0031] 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 adhered via the adhesive layer 33. That is, the first member 31 and the second member 32 are integrated via the adhesive layer 33 by the adhesive layer 33 adhering to both of them.

[0032] (First member, second member) The first member 31 is a disc-shaped member in plan view and has a rib portion 311 on the side facing the second member 32. A groove portion 31x is formed between adjacent rib portions 311.

[0033] The second member 32 is a disc-shaped member in plan view. The contour of the second member 32 overlaps (coincides) with the contour of the first member 31 in plan view.

[0034] The space surrounded by the groove portion 31x and the second member 32 corresponds to the flow path 3f.

[0035] The first member 31 and the second member 32 can use a known metal matrix composite (Metal Material Composite, hereinafter referred to as MMC) as the material. MMC can be adjusted by a known method (metal infiltration method, forging method) of introducing metal into the pores of a porous ceramic substrate after adjusting the porous ceramic substrate.

[0036] The material for forming the first member 31 and the material for forming the second member 32 may be different, but it is preferably the same material. "The same material" means that both the material of the ceramic substrate constituting the MMC and the metal introduced into the pores are the same. When the material for forming the first member 31 and the material for forming the second member 32 are the same material, it is more preferable that the ratio of the metal introduced into the ceramic substrate is also the same.

[0037] More specifically, the MMC that is the material of the first member 31 and the second member 32 preferably contains SiC as a material. Specifically, when the entire first member 31 and the second member 32 are taken as 100% by volume, the MMC preferably contains 75% by volume or more but less than 100% by volume of SiC, and more preferably 75% by volume or more but less than 99% by volume.

[0038] The MMC contains one or more elements selected from the group consisting of aluminum (Al), silicon (Si), and magnesium (Mg) as the metal introduced into the pores. The inclusion of these elements in SiC improves the thermal conductivity of the base 3A, facilitating heat dissipation through the base 3A. In an MMC containing 75% or more by volume of SiC, the thermal expansion coefficient can be reduced to 2.8 × 10 by adjusting the counter material contained in the material. -6 / K~6.8×10 -6 It can be controlled within the range of / K.

[0039] The absolute value of the difference in thermal expansion coefficient between the MMC and the ceramic material of the electrostatic chuck member 2 is 10 ppm / K or less, and preferably 7.0 ppm / K or less. When the material of the base 3A and the material of the electrostatic chuck member 2 satisfy the above relationship, internal stress due to thermal deformation during heating can be easily suppressed.

[0040] The MMC preferably contains 75 to 99 volume % of SiC and 1 to 25 volume % of Al, Si, or Mg, when the entire MMC is taken as 100 volume %. The base 3A formed from an MMC of this composition has a thermal expansion coefficient very close to that of the Al2O3-SiC constituting the electrostatic chuck member 2, and the difference in thermal expansion amount between the base 3A and the electrostatic chuck member 2 during heating is small.

[0041] Examples of MMCs that can be used include Mg-SiC (7.0 ppm / K), Al-SiC (6.8 ppm / K), and Si-SiC (2.8 ppm / K). The amount of metal contained in each MMC can be adjusted appropriately within the above content range depending on the desired thermal expansion coefficient.

[0042] (Adhesive layer) The adhesive layer 33 is made of an organic material and is provided on the entire surface 32a of the second member 32, and is sandwiched between the top surface 311a of the protruding ridge portion 311 and the surface (surface 32a) of the second member 32 facing the first member 31.

[0043] Examples of materials for the adhesive layer 33 include silicone resin, acrylic resin, epoxy resin, and polyimide resin.

[0044] 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 even more preferably 50 μm or more and 120 μm or less.

[0045] 1, the adhesive layer 33 is located below the upper end of the flow path 3 f. In this configuration, the adhesive layer 33 is not interposed between the mounting surface 2 a and the flow path 3 f, so that the adhesive layer 33 made of an organic material is unlikely to impede heat transfer.

[0046] The adhesive layer 33 may be formed by applying a paste-like adhesive to one surface of the second member 32 and hardening it, or by placing a sheet-like adhesive between the first member 31 and the second member 32 and hardening it.

[0047] When the first member 31 and the second member 32 are made of a metal material, methods for joining and integrating them include Si bonding and silver brazing. However, the inventors' investigations revealed that using these methods to integrate members made of MMC unexpectedly poses the following problems.

[0048] First, in the case of Si bonding, when the first member 31 and the second member 32 made of Si-SiC (MMC) were Si-bonded, a location where Si contained in the MMC was ejected inside the formed flow path 3f was confirmed. This is presumably because the metal that had penetrated into the MMC melted due to the heating during Si bonding. If Si ejects into the flow path 3f, there is a risk of blocking the flow path 3f. Also, even if the flow path 3f is not blocked, the cross-sectional area of the flow path 3f decreases, causing pressure loss, which leads to a degradation in the performance of the base 3A.

[0049] The above problem can occur not only when the MMC is Si-SiC, but also when Al-SiC or Mg-SiC in which Al or Mg with a melting point lower than Si has penetrated inside.

[0050] Also, in the case of silver brazing, Si contained in the MMC diffuses from the bonding surface into the silver brazing material, forming an Ag-Si alloy. This may lead to a decrease in the bonding strength between the first member 31 and the second member 32, resulting in a possible decrease in the reliability of the base 3A.

[0051] The above problem can occur not only when the MMC is Si-SiC, but also when it is Al-SiC or Mg-SiC.

[0052] Based on the above findings, in the base 3A of the present embodiment, the first member 31 and the second member 32 are adhered and integrated with an adhesive layer 33 made of an organic-based 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 ejection of the metal in the MMC can be suppressed. Also, the metal in the MMC does not diffuse into the adhesive layer 33 made of the organic-based material.

[0053] A method for manufacturing such a base will be described later.

[0054] The surface of the base 3A is preferably coated with a metal film. As the metal film, for example, an Al sprayed film can be adopted. The film thickness of the metal film can be, 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).

[0055] A hole 3h is provided in the base 3A. The hole 3h extends along the vertical direction. The hole 3h penetrates the base 3A in the vertical direction and opens to the support surface 3a and the lower surface 3b of the base 3A, respectively. The hole 3h is, for example, circular in plan view. An insulator 23 described later is inserted into the hole 3h.

[0056] (Bonding layer) The bonding layer 4 is interposed 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 is preferably a layer made of a mixture containing a resin material and a heat-conductive filler (hereinafter simply referred to as a filler).

[0057] (Bonding layer) The bonding layer 4 is sandwiched between the electrostatic chuck member 2 and the base 3A and adheres 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).

[0058] The bonding layer 4 containing the resin material is relatively more likely to deform than the electrostatic chuck member 2 and the base 3A. Therefore, the bonding layer 4 is more likely to deform following the expansion or contraction of the electrostatic chuck member 2 and the base 3A due to temperature changes, as compared with a bonding layer formed by brazing. Further, for example, even if there is a difference in the thermal expansion amount between the electrostatic chuck member 2 and the base 3A, the internal stress caused by the difference in the thermal expansion amount can be suppressed by the deformation of the bonding layer 4.

[0059] The resin is not particularly limited as long as it is difficult to cause cohesive failure due to thermal stress. For example, silicone resin, acrylic resin, epoxy resin, phenolic resin, polyurethane resin, unsaturated polyester resin, etc. can be mentioned. Among these, silicone resin is preferred because of its high degree of expansion and contraction and its difficulty in causing cohesive failure due to changes in thermal stress.

[0060] The filler has a function of improving the thermal conductivity in the thickness direction of the bonding layer 4. Due to this function, as the filler, one or more selected from the group consisting of inorganic oxides, inorganic nitrides, and inorganic oxynitrides can be mentioned. For example, it is preferable that the filler contains surface-coated aluminum nitride (AlN) particles having a coating layer made of silicon oxide (SiO2) or aluminum oxide (Al2O3) formed on the surface of aluminum nitride (AlN) particles.

[0061] The content of the filler in the bonding layer 4 is 50% by mass or more and 80% by mass or less. The content of the filler is preferably 55% by mass or more, more preferably 60% by mass or more. Also, the content of the filler is preferably 75% by mass or less, more preferably 70% by mass or less. The upper limit value and the lower limit value of the filler content can be arbitrarily combined.

[0062] If the content 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. If the content of the filler is at most the upper limit value, the electrostatic chuck member 2 and the base 3A are likely to deform following the expansion or contraction due to temperature changes.

[0063] When a bonding layer containing a resin material is employed, in a well-known electrostatic chuck device, Al is used as the material for the base. The base made of Al has a larger coefficient of thermal expansion than the electrostatic chuck member made of ceramics and greatly deforms during heating. 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 risk that the bonding layer containing the resin material will break. However, since the base 3A of the present embodiment is made of MMC, the difference in the amount of thermal expansion from the electrostatic chuck member 2 can be reduced, and breakage of the bonding layer can be suppressed.

[0064] Furthermore, in the electrostatic chuck device 1A of the present embodiment, by adopting the base 3A made of MMC, compared with an electrostatic chuck device adopting an Al base, the amount of deformation required of the bonding layer for absorbing the thermal expansion of the electrostatic chuck member 2 and the base 3A can be small. Therefore, compared with an electrostatic chuck device adopting an Al base, the amount of filler included 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.

[0065] When the amount of filler contained in the bonding layer 4 increases, the filler tends to aggregate when the resin material (adhesive) before curing and the filler are kneaded, and it is difficult to disperse the filler in the resin. In order to promote the dispersion of the filler during kneading, the filler is preferably spherical rather than plate-shaped or fibrous.

[0066] Also, in order to promote the dispersion of the filler during kneading, the filler preferably has a bimodal particle size distribution.

[0067] That the filler is in a certain shape and the particle size distribution of the filler is bimodal can be confirmed by the following method.

[0068] 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 for each of the plurality of fillers included in the obtained image, the particle diameter is measured by image analysis. The particle diameter of the filler can be obtained by analysis using the image analysis software attached to the SEM.

[0069] The magnification of the SEM image is not limited as long as the particle diameter of the filler included in the bonding layer 4 can be measured, but it is preferably at a magnification at which at least 200 fillers are included in one field of view of the SEM image. The magnification of the SEM image is preferably, for example, from 100 times to 5000 times.

[0070] The shape (plate-like, fibrous, spherical) of the filler included in the SEM image is confirmed from the obtained measurement values.

[0071] Also, the particle size distribution of the fillers included in the SEM image is obtained from the obtained measurement values, and it is confirmed whether or not it is a bimodal particle size distribution.

[0072] In this embodiment, the filler being "bimodal" means that in the particle size distribution obtained by the above method, there are two or more, preferably two, peaks showing maxima. Regarding the filler used as the material of the electrostatic chuck device 1A being bimodal, in addition to the above method, the particle size distribution of the filler may be measured by a known laser diffraction scattering method for judgment.

[0073] The average particle diameter of the heat conductive filler included in the bonding layer 4 is preferably 1 / 2 or less of the thickness of the bonding layer 4, and more preferably 1 / 2000 or more and 1 / 2 or less. When the average particle diameter of the heat conductive filler is 1 μm or more and 100 μm or less, the thickness of the bonding layer 4 is preferably 2 μm or more and 200 μm or less. By setting the thickness of the bonding layer 4 in this way, it becomes easy to form the bonding layer 4 containing the filler to a uniform thickness, and uneven cooling can be reduced (the heat uniformity can be enhanced).

[0074] The average particle diameter of the filler can be determined by image analysis from the above-described SEM image.

[0075] Such a bonding layer 4 preferably has a thermal conductivity of 0.3 W / mK or more, and 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 apparatus can be appropriately cooled.

[0076] Also, the bonding layer 4 preferably has an elastic modulus at 25°C of 10,000 MPa or less, and more preferably 1,000 MPa or less. When the electrostatic chuck device 1A is used in a plasma process and heated and cooled repeatedly, the bonding layer 4 may be peeled at the interface due to internal stress caused by the difference in thermal expansion between the electrostatic chuck member 2 and the base 3A. On the other hand, when the bonding layer 4 has the above elastic modulus, the bonding layer 4 can relieve the above internal stress and suppress peeling.

[0077] 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, and the presence or absence of peeling after bonding of an MMC base (82% by volume of SiC, 18% by volume of Si) / ceramic material (Al2O3 - SiC) when each filler is added to a silicone resin.

[0078]

Table 1

[0079]

Table 2

[0080] The bonding layer 4 may be formed by sandwiching a liquid adhesive between the electrostatic chuck member 2 and the base 3A and curing it, or by sandwiching a sheet-like or film-like adhesive between the electrostatic chuck member 2 and the base 3A and forming it.

[0081] When the material of the bonding layer 4 is a liquid adhesive, the viscosity of the adhesive is preferably 500 Pa·s or less.

[0082] As described above, when the amount of the filler contained in the bonding layer 4 increases, the adhesive force between the bonding layer 4 and the base 3A tends to decrease. Therefore, it is preferable that a primer layer is formed on the surface of the base 3A that contacts the bonding layer 4.

[0083] The primer layer is made of an organosilicon compound having a functional group that reacts with the resin material (adhesive) which is the material of the bonding layer 4 and an alkoxy group. Examples of the functional group include an epoxy group, a vinyl group, a methacrylic group, and a mercapto group. Further, the organosilicon compound has one or more alkoxy groups. Furthermore, the organosilicon compound may be a single molecule or a polymer. As such an organosilicon compound, a compound known as a material for the primer layer can be used.

[0084] By applying such an organosilicon compound to the surface of the base 3A, the alkoxy group possessed by the organosilicon compound reacts with the surface of the base 3A to form a bond. Also, the functional group possessed by the organosilicon compound reacts with the adhesive to form a bond. Thereby, when the primer layer is formed, a higher adhesive force is generated between the bonding layer 4 and the base 3A compared to the case where there is no primer layer.

[0085] Also, the bonding layer 4 may be a layer made of a metal material as a forming material.

[0086] When the entire bonding layer 4 is taken as 100% by volume, the bonding layer 4 is made of 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 as a forming material. By the bonding layer 4 containing at least one metal selected from the group consisting of Ti, Zr, and Hf, when joining the electrostatic chuck member 2 and the base 3A, the molten alloy obtained by melting the material of the bonding layer 4 easily spreads and wets on the surface of the ceramics (electrostatic chuck member 2), and the joining becomes easy. Further, by the bonding layer 4 containing the above metal, the above metal and the ceramics (electrostatic chuck member 2) easily adhere to each other, generation of voids at the interface can be suppressed, and strong joining becomes possible.

[0087] The thickness of the bonding layer 4 is preferably 0.005 mm or more and 0.5 mm or less.

[0088] When manufacturing the electrostatic chuck device 1A, as the material of the bonding layer 4, a metal foil may be used, or a metal paste obtained by adding a binder to metal powder may be used. These materials are disposed between the electrostatic chuck member 2 and the base 3A, heated to a temperature equal to or higher than the melting point of the metal material forming the bonding layer, and the bonding layer 4 can be formed by the molten metal material spreading and wetting between the electrostatic chuck member 2 and the base 3A.

[0089] (Support plate) The support plate 5 supports the base 3A from the lower surface 3b of the base 3A. Further, 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 higher Young's modulus than the material of the base 3A. For example, as the material of the support plate 5, any of metal, MMC, and ceramics can be adopted. Among them, as the support plate 5, it is preferable to use a ceramic plate such as Al2O3 having a higher Young's modulus than the base 3A.

[0090] The ceramic used for the support plate 5 is preferably the same as the material used for the electrostatic chuck member 2. Specific examples of the ceramic include aluminum oxide and aluminum nitride. By using the same material for 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 the warping of the electrostatic chuck device 1A can be suppressed.

[0091] (Insulator) The insulator 23 is inserted into the hole 3h and the hole 5h and assembled to the base 3A. That is, the insulator 23 functions as an inserted part inserted into the hole 3h and the hole 5h. The insulator 23 has 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 surfaces of the hole 3h and the hole 5h using a joining means such as adhesion. The insulator 23 insulates the metal base 3A and the power supply terminal 16.

[0092] The insulator 23 is made of, 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, ceramics containing one or more selected from AlN, Al2O3, Si3N4, zirconium oxide (ZrO2), sialon, boron nitride (BN), and SiC can be adopted.

[0093] The upper end surface (hereinafter, the upper end surface 23a) of the insulator 23 on the upper side (one side in the lamination direction) abuts on the electrostatic chuck member 2 or is disposed adjacent thereto with an insulating adhesive interposed therebetween and the electrostatic chuck member.

[0094] (Power supply terminal) The power supply terminal 16 extends downward from the suction electrode 13. The power supply terminal 16 is connected to an external power supply 21. The power supply 21 applies a voltage to the suction electrode 13. The number, shape, etc. of the power supply terminals 16 are determined by the form of the suction electrode 13, that is, whether it is a unipolar type or a bipolar type.

[0095] The power supply terminal 16 is inserted into a hole 11h provided in the lower part of the dielectric substrate 11 and reaching the adsorption electrode 13, and a through hole 23h of the insulator 23.

[0096] The hole 11h and the through hole 23h are circular when viewed from the stacking 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.

[0097] According to the base having the above configuration, a novel base made of MMC can be obtained.

[0098] Also, according to the electrostatic chuck device having the above configuration, a novel electrostatic chuck device using a base made of MMC can be provided.

[0099] 《Manufacturing method of the base》 Figs. 2 to 4 are process diagrams showing an example of the manufacturing method of the base 3A, and are cross-sectional views in the same field of view as Fig. 1.

[0100] First, SiC powder, a binder, a plasticizer, etc. are mixed at a predetermined ratio to form a slurry, which is applied and dried to form a pair of green sheets of SiC. Commercially available products may be used as the green sheets.

[0101] Next, as shown in Fig. 2, a pair of green sheets 300 are processed to form a first precursor 301 which is a precursor of the first member and a second precursor 302 which is a precursor of the second member (step of forming the precursor). Specifically, at least one of the pair of green sheets 300 is processed to form a groove portion 301x on one surface 301a. Further, a through hole 301h penetrating in the thickness direction of the green sheet 300 is formed to obtain the first precursor 301.

[0102] Also, a through hole 302h penetrating in the thickness direction is formed in the other green sheet 300 to obtain the second precursor 302.

[0103] Next, as shown in FIG. 3, the first member 31 is manufactured from the first precursor 301, and the second member 32 is manufactured from the second precursor 302 (step of manufacturing the first member and the second member).

[0104] Specifically, the first member 31 is manufactured by firing the first precursor 301 and infiltrating a metal (Si, Al, or Mg) by, for example, 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 member 31. Similarly, the through-hole 301h becomes the through-hole 31h of the first member 31. In the first member 31, a rib portion 311 that protrudes relatively to the groove portion 31x is formed.

[0105] Similarly, the second member 32 is manufactured by firing 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 member 32.

[0106] Next, as shown in FIG. 4, the first member 31 and the second member 32 are adhered (adhering step). Specifically, with the groove portion 31x of the first member 31 on the inner side, the first member 31 and the second member 32 are opposed to each other and adhered with an adhesive. Thereby, the top surface 311a of the rib portion 311 and one surface 32a of the second member 32 (the surface facing the first member 31) are adhered. The adhesive cures to become the adhesive layer 33. The adhesive layer 33 is sandwiched between the top surface 311a and the one surface 32a.

[0107] I As the adhesive, a paste-like or gel-like adhesive having fluidity may be used, or a sheet-like adhesive may be used. Since it is easy to suppress bleeding and easy to process, it is preferable to use a sheet-like adhesive.

[0108] The space surrounded by the groove portion 31x and one surface 32a of the second member 32 (the adhesive layer 33 formed on the one surface 32a) becomes the flow path 3f.

[0109] In the subsequent layer 33, a through-hole 33h is formed so as to overlap the through-hole 31h of the first member 31 and the through-hole 32h of the second member 32 in a planar manner. By curing the adhesive, a hole portion 3h in which the through-hole 31h, the through-hole 32h, and the through-hole 33h communicate with each other is obtained.

[0110] According to the method for manufacturing the base having the above-described configuration, since the green sheet is used as a starting material, it is possible to easily manufacture a base made of MMC that is difficult to process. Further, by using an organic material (organic adhesive) for bonding the first member 31 and the second member 32, the two can be suitably integrated to manufacture the base 3A.

[0111] (Modification example) In the present embodiment, in the base 3A, the adhesive layer 33 is provided on the entire surface of one surface 32a of the second member 32, but the present invention is not limited to this.

[0112] FIGS. 5 and 6 are explanatory views of a base according to a modification example and correspond to FIG. 4.

[0113] The base 3B shown in FIG. 5 includes a first member 31, a second member 32, and an adhesive layer 35. The adhesive layer 35 has a through-hole 35h that overlaps the hole portion 3h and a through-hole 35x that overlaps the groove portion 31x of the first member 31. That is, in the base 3B, the adhesive layer 35 is formed only at a position in contact with the top surface 311a of the rib portion 311.

[0114] In such a base 3B, a space surrounded by the groove portion 31x, one surface 32a of the second member 32, and the through-hole 35x forms a flow path 3f.

[0115] The base 3C shown in FIG. 6 includes a first member 36, a second member 37, and an adhesive layer 35.

[0116] The first member 36 is a disc-shaped member in 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.

[0117] The second member 37 is a disc-shaped member in plan view. The contour of the second member 37 overlaps the contour of the first member 36 in 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.

[0118] Such first member 36 and second member 37 can be manufactured by the same method as the method for manufacturing the above-described first member 31.

[0119] 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. Thereby, 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.

[0120] 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. Further, the through hole 36h, the through hole 37h, and the through hole 35h communicate with each other to form a hole portion 3h.

[0121] 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.

[0122] Such a base 3B or base 3C can be used as the base provided in the electrostatic chuck device by replacing it with the base 3A of the electrostatic chuck device 1A shown in FIG. 1.

[0123] The base plates 3B and 3C are novel base plates made of MMC. Also, compared with the base plate 3A, the area of the adhesive layer exposed on the inner surface of the flow path 3f is smaller in the base plates 3B and 3C. Therefore, in the electrostatic chuck device having the base plates 3B and 3C, heat transfer is less likely to be inhibited by the adhesive layer, the heat transmitted from the mounting surface can be suitably removed, and the temperature distribution on the mounting surface can be made uniform.

[0124] As described above, the preferred embodiments of the present invention have been described with reference to the accompanying drawings, but the present invention is not limited to such examples. The various shapes, combinations, etc. of the constituent members shown in the above examples are merely examples, and can be variously changed based on design requirements and the like without departing from the gist of the present invention.

Explanation of Reference Numerals

[0125] 1A...Electrostatic chuck device, 2...Electrostatic chuck member, 2a...Mounting surface, 3A, 3B, 3C...Base plates, 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

Claims

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

2. The base according to claim 1, wherein the adhesive layer is formed only at a position in contact with the top surface of the ribbed 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 below the upper end of the flow path.

5. An electrostatic chuck member made of a ceramic material; The base according to claim 1 or 2; A bonding layer for bonding the electrostatic chuck member and the base, and comprising: The electrostatic chuck member contains 50% by volume or more of aluminum oxide when the entire electrostatic chuck member is 100% by volume.

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

7. A step of forming a precursor in which a groove portion is formed in at least one of a pair of green sheets; A step of infiltrating a metal into a sintered body obtained by firing the precursor to produce a first member made of a metal matrix composite material and a second member made of a metal matrix composite material and overlapping the first member; A method for manufacturing a base, comprising a step of opposing the first member and the second member with the groove portion on the inner side and bonding the first member and the second member with an organic sheet adhesive.

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