Members for semiconductor manufacturing equipment

Abstract

A ceramic substrate having an upper surface for placing a wafer and a lower surface opposite to the upper surface, a plug placement hole penetrating the ceramic substrate in the vertical direction, a dielectric plug embedded in the plug placement hole, the dielectric plug having a lower surface and a gas passage portion penetrating the dielectric plug, a film having a lower volume resistivity than the dielectric plug covering at least a part of the lower surface of the dielectric plug, a conductive base plate bonded to the lower surface of the ceramic substrate via a resin adhesive layer, a gas passage for supplying gas to the gas passage portion of the dielectric plug passing through the base plate and the resin adhesive layer, a conductive connecting portion provided in the gas passage and having an upper end electrically connected to the film and a lower end electrically connected to the base plate, and at least a part of the film covering the lower surface of the dielectric plug is in contact with the resin adhesive layer, a member for a semiconductor manufacturing apparatus.

Description

Technical Field

[0001] The present invention relates to a member for a semiconductor manufacturing apparatus.

Background Art

[0002] Conventionally, members for semiconductor manufacturing apparatuses used for holding, temperature control, conveyance, etc. of wafers are known. This type of member for a semiconductor manufacturing apparatus is also referred to as a wafer stage, an electrostatic chuck, a susceptor, etc., and generally has a function of applying electrostatic adsorption power to built-in electrodes and adsorbing a wafer by electrostatic force, and a function of controlling the temperature of the wafer by flowing a gas between the wafer mounting surface and the wafer which is an object to be adsorbed is also known.

[0003] As a member for a semiconductor manufacturing apparatus, for example, a ceramic substrate having an upper surface for mounting a wafer and a lower surface opposite to the upper surface, a gas passage portion penetrating the ceramic substrate in the vertical direction, and a conductive base plate joined to the lower surface of the ceramic substrate are known.

[0004] In such a member for a semiconductor manufacturing apparatus, a large potential difference may occur between the wafer and the base plate, and discharge (dielectric breakdown) may occur between the wafer and the base plate through the gas passage portion. For this reason, various techniques have been developed to suppress discharge.

[0005] Patent Document 1 proposes a plug having a gas flow path portion penetrating a dense main body portion while being bent in the thickness direction. It is also proposed that at least a part of the entire length of the gas flow path portion be made of an insulating and breathable porous material. And Patent Document 1 describes that in the porous section, since the three-dimensionally (for example, three-dimensional network) continuous pores existing in the porous material serve as gas flow paths, the substantial flow path length in the gas flow path portion becomes longer than when the entire gas flow path portion is a cavity, and discharge is less likely to occur.

[0006] Patent Document 2 discloses an electrostatic chuck comprising a ceramic dielectric substrate having a first main surface on which an object to be adsorbed is placed and a second main surface opposite to the first main surface, a base plate that supports the ceramic dielectric substrate and has a gas introduction passage, and a first porous portion provided between the base plate and the first main surface of the ceramic dielectric substrate at a position facing the gas introduction passage. The ceramic dielectric substrate has a first hole portion located between the first main surface and the first porous portion. The first porous portion has a porous portion having a plurality of holes and a first dense portion denser than the porous portion. When projected onto a plane perpendicular to a first direction from the base plate toward the ceramic dielectric substrate, the first dense portion and the first hole portion overlap, and the porous portion and the first hole portion are configured not to overlap.

[0007] According to Patent Document 2, in this electrostatic chuck, since the first dense portion and the first hole portion are configured to overlap, the generated current tries to flow around the first dense portion. Therefore, the distance (conductive path) through which the current flows can be increased, making it difficult for electrons to be accelerated, and thus suppressing the occurrence of arc discharge.

[0008] Patent Document 3 discloses an electrostatic chuck comprising a ceramic dielectric substrate having a first main surface on which an object to be adsorbed is placed and a second main surface opposite to the first main surface, a base plate that supports the ceramic dielectric substrate and has a gas introduction passage, and a first porous portion provided between the base plate and the first main surface of the ceramic dielectric substrate at a position facing the gas introduction passage. The first porous portion has a plurality of porous portions having a plurality of holes and a dense portion having a density higher than that of the porous portions. Each of the plurality of porous portions extends in a first direction from the base plate toward the ceramic dielectric substrate, the dense portion is located between the plurality of porous portions, the porous portion has the holes and a wall portion provided between the holes, and in a second direction substantially orthogonal to the first direction, the minimum value of the dimension of the wall portion is smaller than the minimum value of the dimension of the dense portion.

[0009] According to Patent Document 3, in this electrostatic chuck, since the first porous portion is provided with a hydrophobic portion and a dense portion extending in the first direction, it is said that while ensuring resistance to arc discharge and gas flow rate, the mechanical strength (rigidity) of the first porous portion can be improved.

[0010] Patent Document 4 describes an invention that aims to provide a holding device capable of controlling the temperature of an object with high precision while reducing the occurrence of abnormal discharge. Specifically, it includes a ceramic substrate having a first surface for holding an object and a second surface located on the opposite side of the first surface, a base member disposed on the second surface side of the ceramic substrate and having a third surface located on the opposite side of the ceramic substrate, and a bonding material disposed between the ceramic substrate and the base member. (1) In the ceramic substrate and the base member, a flow path is formed that allows fluid to move communicatively between an outflow hole provided in the first surface and an inflow hole provided in the third surface, or (2) in the ceramic substrate, a flow path is formed that allows fluid to move communicatively between an outflow hole provided in the first surface and an inflow hole provided in the second surface, and the flow path is provided with a porous ceramic region, and the porous ceramic region includes a hydrophobic region and a dense region having a lower porosity than the hydrophobic region and disposed closer to the first surface side than the hydrophobic region. A holding device is described.

[0011] In Patent Document 5, in a wafer mounting table, an insulating first porous portion disposed in a through hole of a ceramic plate and an insulating second porous portion fitted into a recess provided on the ceramic plate side of a base plate so as to face the first porous portion are provided. The gas supplied to the gas introduction path passes through the second porous portion and the first porous portion and flows into the space between the wafer mounting surface and the wafer, and is used for cooling the object. It is described that the presence of the first porous portion and the second porous portion can suppress the occurrence of discharge (arc discharge) caused by plasma when processing the wafer while ensuring the gas flow rate from the gas introduction passage to the wafer mounting surface.

Prior Art Documents

Patent Documents

[0012]

Patent Document 1

Patent Document 2

Patent Document 3

Patent Document 4

Patent Document 5

Summary of the Invention

Problems to be Solved by the Invention

[0013] Thus, in the member for a semiconductor manufacturing apparatus, various techniques for improving the structure of the gas passage portion penetrating the ceramic substrate in the vertical direction have been proposed in order to suppress the discharge generated between the wafer and the base plate. However, it is considered meaningful for the development of the technology of the member for a semiconductor manufacturing apparatus to develop a technology for suppressing discharge by a different approach. In particular, there is still room for improvement in the technology for suppressing the discharge generated in the vicinity of the joint portion between the ceramic substrate and the base plate of the gas passage portion penetrating the ceramic substrate in the vertical direction.

[0014] In view of the above circumstances, an object of the present invention in one embodiment is to provide a member for a semiconductor manufacturing apparatus suitable for suppressing the discharge generated in the vicinity of the joint portion between the ceramic substrate and the base plate of the gas passage portion penetrating the ceramic substrate in the vertical direction.

Means for Solving the Problems

[0015] The present inventor has intensively studied to solve the above problems and created the present invention exemplified below.

[0016] [Aspect 1] A ceramic substrate having an upper surface for placing a wafer and a lower surface opposite to the upper surface, A plug placement hole penetrating the ceramic substrate in the vertical direction, A dielectric plug embedded in the plug placement hole, the dielectric plug having a lower surface and a gas passage portion penetrating the dielectric plug, A first film covering at least a part of the lower surface of the dielectric plug and made of a material having a lower volume resistivity than the material constituting the dielectric plug, A conductive base plate adhesively bonded to the lower surface of the ceramic substrate via a resin adhesive layer, A gas passage for supplying gas to the gas passage portion of the dielectric plug through the base plate and the resin adhesive layer, A conductive connecting portion provided in the gas passage, having an upper end electrically connected to the first film and a lower end electrically connected to the base plate, Comprising, At least a part of the first film is in contact with the resin adhesive layer, or at least a part of the lower surface of the ceramic substrate is covered with a second film made of a material having a lower volume resistivity than the material constituting the ceramic substrate, and at least a part of the second film is in contact with the resin adhesive layer and in contact with the first film, A member for a semiconductor manufacturing apparatus. [Aspect 2] The member for a semiconductor manufacturing apparatus according to Aspect 1, wherein at least a part of the first film is in contact with the resin adhesive layer. [Aspect 3] The member for a semiconductor manufacturing apparatus according to Aspect 1 or 2, wherein at least a part of the lower surface of the ceramic substrate is covered with a second film made of a material having a lower volume resistivity than the material constituting the ceramic substrate, and at least a part of the second film is in contact with the resin adhesive layer and in contact with the first film. [Aspect 4] The connecting part has a member with elasticity, and the member with elasticity is pressed against a first film on the lower surface of the dielectric plug and compressed. The member for a semiconductor manufacturing apparatus according to any one of Aspects 1 to 3. [Aspect 5] The connecting part has a member with elasticity, and the member with elasticity is pressed against a second film on the lower surface of the ceramic substrate and compressed. The member for a semiconductor manufacturing apparatus according to any one of Aspects 1 to 4. [Aspect 6] The material constituting the dielectric plug and the material constituting the ceramic substrate both contain one or more selected from aluminum oxide, aluminum nitride, quartz, and zirconia. The member for a semiconductor manufacturing apparatus according to any one of Aspects 1 to 5. [Aspect 7] The first film on the lower surface of the dielectric plug contains a metal, carbon, a conductive ceramic, or a composite material of two or more of these. The member for a semiconductor manufacturing apparatus according to any one of Aspects 1 to 6. [Aspect 8] The second film on the lower surface of the ceramic substrate contains a metal, carbon, a conductive ceramic, or a composite material of two or more of these. The member for a semiconductor manufacturing apparatus according to any one of Aspects 1 to 7. [Aspect 9] The dielectric plug is an inorganic dielectric plug having a dense outer peripheral surface, and the outer peripheral surface is embedded in the plug placement hole so as to directly fit with the inner peripheral surface of the plug placement hole. The member for a semiconductor manufacturing apparatus according to any one of Aspects 1 to 8. [Aspect 10] The inner peripheral edge of the through-hole of the resin adhesive layer that partitions the gas passage is configured such that the gas passage widens upward. The member for a semiconductor manufacturing apparatus according to any one of Aspects 1 to 9. [Aspect 11] The inner peripheral surface of the plug placement hole that fits with the dense outer peripheral surface of the dielectric plug is dense. The member for a semiconductor manufacturing apparatus according to the aspect 9 described. [Advantages of the Invention]

[0017] The member for a semiconductor manufacturing apparatus according to an embodiment of the present invention is effective in suppressing discharge generated between a wafer and a base plate, particularly discharge generated in the vicinity of the joint between the ceramic substrate and the base plate of a gas passage portion that penetrates the ceramic substrate in the vertical direction.

Brief Description of the Drawings

[0018]

Figure 1

Figure 2A

Figure 2B

Figure 3

Embodiments for Carrying Out the Invention

[0019] Next, embodiments of the present invention will be described in detail with reference to the drawings. It should be understood that the present invention is not limited to the following embodiments, and design changes, improvements, etc. can be appropriately made based on the ordinary knowledge of those skilled in the art without departing from the spirit of the present invention. Also, in this specification, "upper" and "lower" are used to conveniently represent the relative positional relationship when the base plate of the member for a semiconductor manufacturing apparatus is placed on a horizontal plane with the base plate on the lower side, and do not represent an absolute positional relationship. Therefore, depending on the orientation of the member for a semiconductor manufacturing apparatus, "upper" and "lower" may become "lower" and "upper", "left" and "right", or "front" and "rear".

[0020] <1. Configuration of the Member for a Semiconductor Manufacturing Apparatus> Referring to FIGS. 2A and 2B, a member 10 for a semiconductor manufacturing apparatus according to an embodiment of the present invention includes a ceramic substrate 20 having an upper surface 21 for placing a wafer and a lower surface 23 opposite to the upper surface 21, and a plug arrangement hole 50 that penetrates the ceramic substrate 20 in the vertical direction, and A dielectric plug 55 embedded in the plug placement hole 50, the dielectric plug 55 having a lower surface 55a and a gas passage portion 55c passing through the dielectric plug 55, A first film 56 covering at least a part of the lower surface 55a of the dielectric plug 55 and made of a material having a lower volume resistivity than the material constituting the dielectric plug 55, A conductive base plate 30 adhesively bonded to the lower surface 23 of the ceramic substrate 20 via a resin adhesive layer 40, A gas passage 60 for supplying gas to the gas passage portion 55c of the dielectric plug 55 through the base plate 30 and the resin adhesive layer 40, A conductive connecting portion 70 provided in the gas passage 60, having an upper end 70a electrically connected to the first film 56 and a lower end 70b electrically connected to the base plate 30, is provided.

[0021] The ceramic substrate 20 can be, for example, a ceramic disk (e.g., with a diameter of 300 to 400 mm and a thickness of 1 to 5 mm) such as an alumina sintered body or an aluminum nitride sintered body. The upper surface 21 of the ceramic substrate 20 has a wafer placement surface for placing the wafer W. The ceramic substrate 20 incorporates electrodes 22. As shown in FIG. 1, an annular seal band 21a is formed along the outer edge on the upper surface 21 of the ceramic substrate 20, and a plurality of small protrusions 21b are formed on the entire inner surface of the seal band 21a. The shape of the small protrusions 21b is not limited, and can be, for example, a cylinder, a prism, etc. The seal band 21a and the small protrusions 21b are preferably of the same height, and the height can be, for example, 5 to 100 μm, and typically 10 to 30 μm. The electrode 22 is a planar electrode used as an electrostatic electrode and is connected to an external DC power supply via a power supply member (not shown). A low-pass filter may be arranged in the middle of the power supply member. The power supply member is electrically insulated from the resin adhesive layer 40 and the base plate 30. When a DC voltage is applied to this electrode 22, the wafer W is adsorbed and fixed to the wafer placement surface (specifically, the upper surfaces of the seal band 21a and the small protrusions 21b) by the electrostatic adsorption force, and when the application of the DC voltage is released, the adsorption and fixation of the wafer W to the wafer placement surface is released. Note that the portion of the upper surface 21 of the ceramic substrate 20 where the seal band 21a and the small protrusions 21b are not provided is referred to as a reference surface 21c.

[0022] As the electrode 22, instead of or in addition to the electrostatic electrode, a heater electrode (resistance heating element) may be incorporated. In this case, a heater power supply is connected to the heater electrode. The ceramic substrate 20 may incorporate one layer of electrodes, or may incorporate two or more layers with a gap therebetween.

[0023] The conductive base plate 30 is a disk (a disk having the same diameter as or a larger diameter than the ceramic substrate 20) with good electrical conductivity and thermal conductivity. Inside the base plate 30, a refrigerant flow path 32 through which a refrigerant circulates may be formed. The refrigerant flowing through the refrigerant flow path 32 is preferably a liquid and preferably has electrical insulation properties. Examples of the electrically insulating liquid include fluorine-based inert liquids. The refrigerant flow path 32 can be formed, for example, in one continuous stroke from one end (inlet) to the other end (outlet) over the entire base plate 30 in a plan view. At one end and the other end of the refrigerant flow path 32, a supply port and a recovery port of an external refrigerant device (not shown) are respectively connected. The refrigerant supplied from the supply port of the external refrigerant device to one end of the refrigerant flow path 32 returns from the other end of the refrigerant flow path 32 to the recovery port of the external refrigerant device after passing through the refrigerant flow path 32, and after being temperature-adjusted, is again supplied from the supply port to one end of the refrigerant flow path 32. The base plate 30 is connected to a high-frequency (RF) power supply and can also be used as an RF electrode.

[0024] Examples of the material of the base plate 30 include a metal material and a composite material of a metal and ceramics. Examples of the metal material include Al, Ti, Mo, W, or their alloys. Examples of the composite material of a metal and ceramics include a metal matrix composite material (MMC) and a ceramic matrix composite material (CMC). Specific examples of such composite materials include a material containing Si, SiC, and Ti (also referred to as SiSiCTi), a material obtained by impregnating a SiC porous body with Al and / or Si, and a composite material of Al2O3 and TiC. A material obtained by impregnating a SiC porous body with Al is called AlSiC, and a material obtained by impregnating a SiC porous body with Si is called SiSiC. As the material of the base plate 30, it is preferable to select a material having a thermal expansion coefficient close to that of the material of the ceramic substrate 20. For example, when the ceramic substrate 20 is made of alumina, the base plate is preferably made of SiSiCTi or AlSiC.

[0025] As shown in FIGS. 2A and 2B, the upper surface 31 of the base plate 30 is adhered to the lower surface 23 of the ceramic substrate 20 via a resin adhesive layer 40. The resin adhesive layer 40 can be composed of, for example, a cured product of a silicone resin-based adhesive, an epoxy resin-based adhesive, an acrylic resin-based adhesive, or a urethane resin-based adhesive. The uncured adhesive is preferably provided in the form of a resin adhesive sheet. There is no particular limitation on the curing method, but for example, a heat curing method can be mentioned. For the reason of increasing the adhesive strength, a method of curing while heating and pressurizing (e.g., autoclave) is preferable. In order to improve the uniformity of the thickness of the resin adhesive layer 40, a spacer (not shown) may be disposed between the upper surface 31 of the base plate 30 and the lower surface 23 of the ceramic substrate 20.

[0026] As shown in FIGS. 2A and 2B, the plug placement hole 50 is a hole that penetrates the ceramic substrate 20 in the vertical direction. The plug placement hole 50 is a gas passage from the lower surface 23 of the ceramic substrate 20 to the reference surface 21c of the upper surface 21. The horizontal opening diameter of the plug placement hole 50 (when the cross section of the plug placement hole is not circular, it means the equivalent diameter of a circle) is not limited, but for example, it can be in the range of 1 to 5 mm at any height position, and typically can be in the range of 3 to 4 mm. In the present embodiment, the plug placement hole 50 tapers from bottom to top, and the inner peripheral surface 50a of the plug placement hole 50 is a tapered surface. Thereby, even if an upward pushing force is applied to the dielectric plug 55 from the connecting portion 70, the possibility that the dielectric plug 55 moves upward and the contact with the connecting portion 70 becomes weak or the dielectric plug 55 is pulled out from the ceramic substrate 20 can be reduced.

[0027] As shown in FIG. 1, a plurality (here, 36) of plug placement holes 50 are provided. The plug placement holes 50 can have, for example, a frustum of a cone shape or a frustum of a pyramid shape. A dielectric plug 55 is embedded in the plug placement holes 50. The plug 55 has a gas passage portion 55c that penetrates the inside of the plug 55. In one embodiment, the gas passage portion 55c has one opening on the lower surface 55a of the plug 55 and the other opening on the upper surface 55d, and penetrates the inside of the plug 55 in the vertical direction. In another embodiment, the gas passage portion 55c has one opening on the lower surface 55a of the plug 55 and the other opening on the outer peripheral surface 55b, and penetrates the inside of the plug 55. Here, the dielectric plug 55 is fixed in a state of being filled in the plug placement hole 50. There is no particular limitation on the fixing method, but for example, the outer peripheral surface 55b of the dielectric plug 55 and the inner peripheral surface 50a of the plug placement hole 50 may be directly fixed so as to fit. As a method of direct fitting, a method of embedding by press-fitting the dielectric plug 55 into the plug placement hole 50 can be mentioned. The dielectric plug 55 preferably has an outer shape that is the same shape (e.g., frustum of a cone shape or frustum of a pyramid shape) as the plug placement hole 50. In this case, in order to obtain a desired fixing strength, the horizontal cross-sectional diameter at an arbitrary height position of the dielectric plug 55 is preferably slightly larger (e.g., about 5 to 20 μm in terms of the equivalent diameter of a circle) than the cross-sectional diameter of the plug placement hole 50 at the same height position. Also, as a method of direct fitting, a method in which a male screw portion provided on the outer peripheral surface 55b of the dielectric plug 55 is screwed into a female screw portion provided on the inner peripheral surface 50a of the plug placement hole 50 can be mentioned. Further, the outer peripheral surface 55b of the dielectric plug 55 and the inner peripheral surface 50a of the plug placement hole 50 may be adhered via an adhesive. However, in the case of the fixing method using an adhesive, since the fixing strength of the plug is likely to decrease due to the consumption or deterioration of the adhesive, it is preferable to adopt the method of direct fitting. By directly fitting the two, no gap is generated between the dielectric plug 55 and the plug placement hole 50 due to deterioration such as corrosion or erosion of the adhesive. For this reason, the advantage of being able to prevent discharge caused by deterioration of the adhesive and the dropout of the dielectric plug 55 can be obtained.

[0028] The height position of the upper surface 55d of the dielectric plug 55 is not limited. Therefore, it may be the same height as the reference surface 21c of the ceramic substrate 20 or a different height. However, it is preferable that the height position of the upper surface 55d of the dielectric plug 55 is the same height as the reference surface 21c. When the upper surface of the dielectric plug 55 is lower than the reference surface 21c, it is preferable to arrange it at a lower position within a range of 0.5 mm or less (preferably 0.2 mm or less, more preferably 0.1 mm or less) in order to suppress the occurrence of discharge. When the upper surface of the dielectric plug 55 is higher than the reference surface 21c, there is no particular limitation as long as it is lower than the upper surface of the small protrusion 21b and the outflow of gas from the dielectric plug 55 is not hindered.

[0029] The height position of the lower surface 55a of the dielectric plug 55 is not particularly limited as long as at least a part of the first film 56 can contact the resin adhesive layer 40. Therefore, it may be the same height as the lower surface 23 of the ceramic substrate 20 or a different height. For example, the lower surface 55a of the dielectric plug 55 may protrude downward from the lower surface 23 of the ceramic substrate 20, or the lower surface 55a of the dielectric plug 55 may be 23 located above the lower surface of the ceramic substrate 20.

[0030] The material constituting the dielectric plug 55 is preferably an inorganic dielectric, for example, it can be ceramics. In a preferred embodiment, it can contain one or more selected from aluminum oxide, aluminum nitride, quartz, and zirconia. It can also be composed of only one or two selected from aluminum oxide and aluminum nitride excluding impurities. For example, a plurality of plugs with different materials in the vertical direction can also be stacked and arranged. In this case, the upper plug is made of ceramics with a higher volume resistivity than the lower plug, and by bringing the lower plug into contact with the base plate or the connecting part, the potential of the lower plug can be lowered, aiming at the effect of suppressing the discharge on the lower side where the space is wide and discharge is likely to occur. Specifically, the upper plug can be made of aluminum oxide and the lower plug can be made of SiC, and they can be arranged in the plug arrangement holes in order.

[0031] From the viewpoint of maintaining the fixing strength of the dielectric plug 55, it is preferable that the difference in the coefficient of thermal expansion between the dielectric plug 55 and the ceramic substrate 20 is small. For this reason, the material constituting the dielectric plug 55 and the material constituting the ceramic substrate 20 preferably contain at least one selected from aluminum oxide and aluminum nitride, and more preferably have the same material composition.

[0032] The dielectric plug 55 preferably has a dense outer peripheral surface 55b. When the dielectric plug 55 has a dense outer peripheral surface 55b, particularly when directly fitting with the inner peripheral surface 50a of the plug placement hole 50, sufficient frictional force acts, thereby enhancing the fixing strength of the dielectric plug 55. The dense outer peripheral surface 55b means that the porosity of the outer peripheral surface 55b is 10% or less. The porosity of the outer peripheral surface 55b is preferably 5% or less, and more preferably 1% or less. The porosity of the outer peripheral surface 55b is measured by the following method. The dielectric plug 55 is cut so that a cross section perpendicular to the outer peripheral surface 55b of the dielectric plug 55 is exposed. Next, a portion with a thickness of 100 μm from the outer peripheral surface 55b of the cross section is observed at a magnification of 3000 times using a scanning electron microscope (SEM) for about 2200 μm 2 and the area ratio of the pores confirmed in the thickness portion is determined. Specifically, by image-analyzing the SEM image, a threshold value is determined by discriminant analysis (Otsu's binarization) from the luminance distribution of the luminance data of the pixels in the image. Then, each pixel in the image is binarized into an object portion and a pore portion based on the determined threshold value, and the area of the object portion and the area of the pore portion are calculated. And the ratio of the area of the pore portion to the total area (the total area of the object portion and the pore portion) is determined. The same measurement is performed at five locations on the same dielectric plug 55, and the average value of the five locations is taken as the porosity of the outer peripheral surface 55b of the dielectric plug 55.

[0033] Particularly when the outer peripheral surface 55b of the dielectric plug 55 and the inner peripheral surface 50a of the plug placement hole 50 are directly fitted together, from the viewpoint of increasing the fixing strength due to the friction of the dielectric plug 55, it is preferable that the inner peripheral surface 50a of the plug placement hole 50 is also dense. The dense inner peripheral surface 50a means that the porosity of the inner peripheral surface 50a is 5% or less. The porosity of the inner peripheral surface 50a is preferably 1% or less, and more preferably 0.5% or less. Since the inner peripheral surface 50a is a part of the ceramic substrate 20, in this specification, the value of the porosity of the ceramic substrate 20 is regarded as the porosity of the inner peripheral surface 50a. The porosity of the ceramic substrate 20 is defined as the open porosity measured in accordance with JIS R1634:1998, and the average value of the open porosity for five samples taken without bias from the ceramic substrate 20 is taken as the measured value.

[0034] The dielectric plug 55 has a gas passage portion 55c penetrating therethrough. In one embodiment, the gas passage portion 55c has a structure in which the gas flowing in from the lower surface 55a of the dielectric plug 55 can flow through the gas passage portion 55c and flow out from the upper surface 55d of the dielectric plug 55. For example, the gas passage portion 55c may be formed by forming one or more gas flow paths penetrating in the vertical direction in a dense material that does not allow the flow of gas. In this case, the gas flowing in from the lower surface 55a of the dielectric plug 55 flows through the gas flow path and flows out from the upper surface 55d of the dielectric plug 55. The gas flow path may be constituted by any of a straight line, a curve, and a combination of both, but from the viewpoint of suppressing discharge, it is preferable to have a shape such that the flow path length is longer than the vertical length of the dielectric plug 55, for example, a bent shape such as a spiral shape or a zigzag shape. That the dielectric plug 55 is dense means that the porosity of the dielectric plug 55 is 5% or less. The porosity of the dielectric plug 55 is preferably 1% or less, and more preferably 0.5% or less. The porosity of the dielectric plug 55 is measured by the following method. The dielectric plug 55 is cut so as to expose a cross section passing through a central axis extending in the up-down direction of the dielectric plug 55. Next, the cross section, excluding the gas flow paths, is observed at a magnification of 3000 times and a resolution of 2200 μm using a scanning electron microscope (SEM). 2 The area ratio of the pores observed in the relevant portion is determined. Specifically, the SEM image is analyzed, and a threshold is determined from the brightness distribution of the brightness data of the pixels in the image using a discriminant analysis method (Otsu's binarization). Then, based on the determined threshold, each pixel in the image is binarized into an object portion and a pore portion, and the area of the object portion and the area of the pore portion are calculated. Then, the ratio of the area of the pore portion to the total area (the total area of the object portion and the pore portion) is determined. Similar measurements are performed at five locations on the same dielectric plug 55, and the average value of the five locations is determined as the porosity of the dielectric plug 55.

[0035] Examples of methods for providing a gas flow path in the dense dielectric plug 55 include a method of firing a molded body formed using additive manufacturing technology such as a 3D printer, and a method of firing a molded body formed by mold casting using a master model produced by a lost wax method. Mold casting is disclosed in, for example, Japanese Patent No. 7144603.

[0036] Also, a porous portion may be provided in the dielectric plug 55 to form the gas passage 55c. When the gas passage 55c is porous, the gas flowing in from the lower surface 55a of the dielectric plug 55 flows through the gas passage 55c formed by a large number of continuous pores, and flows out from the upper surface 55d of the dielectric plug 55. Since the three-dimensionally (for example, three-dimensionally network-like) continuous pores existing in the porous portion become the gas flow path, the substantial flow path length in the gas passage 55c becomes longer than when the gas passage 55c is a cavity, and an effect of making it difficult for discharge to occur is obtained. The porous gas passage can be formed on the inner periphery side of the dense outer periphery. It is also possible to form one or more gas flow paths in the porous gas passage.

[0037] Therefore, the gas passage portion 55c can be either hollow or porous. It is preferable that at least a part of the gas passage portion 55c is porous. When the gas passage portion 55c is hollow, it means that the porosity is 100%. When the gas passage portion 55c is porous, it means that the porosity of the gas passage portion 55c exceeds 5% and is less than 100%. The porosity of the gas passage portion 55c is preferably large to reduce the ventilation resistance. Therefore, the porosity of the gas passage portion 55c is preferably 10% or more, and more preferably 40% or more. On the other hand, the porosity of the gas passage portion 55c is preferably 50% or less in order to increase the flow path length of the dielectric plug 55 or ensure the structural strength. Therefore, the porosity of the gas passage portion 55c is preferably, for example, 10% or more and 50% or less, and more preferably 40% or more and 50% or less. The porosity of the gas passage portion 55c is measured by the mercury intrusion method (JIS R1655:2003).

[0038] The porosity of the dielectric plug and the ceramic substrate can be controlled, for example, by adjusting the content of the pore-forming material in the raw material composition before firing the ceramics, which are the materials constituting them. For example, in order to densify the outer peripheral surface of the dielectric plug, the amount of the pore-forming material near the outer peripheral surface may be partially reduced or not used. Also, in order to densify the inner peripheral surface of the plug placement hole, the amount of the pore-forming material near the inner peripheral surface may be partially reduced or not used.

[0039] The lower surface 55a of the dielectric plug 55 is covered with a first film 56 made of a material having a lower volume resistivity than the material constituting the dielectric plug 55. The first film 56 may cover a part of the lower surface 55a of the dielectric plug 55 or may cover the whole. Since the first film 56 is thin, gas passage is allowed regardless of whether it is dense or porous. The volume resistivity of the material constituting the first film 56 is preferably 74×10 -8 Ω·m or less at 20°C, and preferably 60×10 -8 Ω·m or less, and preferably 53×10 -8It is preferably below Ω·m. There is no particular lower limit for the volume resistivity of the material constituting the first film 56, but from the viewpoint of availability, at 20 °C, 2×10 -8 It is preferably Ω·m or more, and preferably 3×10 -8 It is preferably Ω·m or more, and preferably 10×10 -8 It is preferably Ω·m or more. Therefore, the volume resistivity of the material constituting the first film 56 is, for example, 2×10 -8 It is preferably Ω·m or more and 74×10 -8 It is preferably Ω·m or less, and more preferably 3×10 -8 It is preferably Ω·m or more and 60×10 -8 It is more preferably Ω·m or less, and even more preferably 10×10 -8 It is preferably Ω·m or more and 53×10 -8 It is even more preferably Ω·m or less. The volume resistivity of the material constituting the first film 56 is measured by a method according to JIS C2525:1999.

[0040] From the viewpoint of suppressing discharge, in addition to the lower surface 55a of the dielectric plug 55, the lower surface 23 of the ceramic substrate 20 is also preferably coated with a second film 57 made of a material having a lower volume resistivity than the material constituting the ceramic substrate 20. And at least a part of the second film 57 preferably contacts the resin adhesive layer 40 and also contacts the first film 56 (see FIG. 2B). In this case, even if at least a part of the first film 56 does not contact the resin adhesive layer 40, discharge can be suppressed. The volume resistivity of the material constituting the second film 57 is preferably 74×10 -8 Ω·m or less at 20 °C, preferably 60×10 -8 Ω·m or less, and preferably 53×10 -8 Ω·m or less. There is no particular lower limit for the volume resistivity of the material constituting the second film 57, but from the viewpoint of availability, at 20 °C, 2×10 -8 It is preferably Ω·m or more, and preferably 3×10 -8 It is preferably Ω·m or more, and preferably 10×10 -8 It is preferably Ω·m or more. Therefore, the volume resistivity of the material constituting the second film 57 is, for example, 2×10 -874×10 or more Ω·m -8 preferably 3×10 or less Ω·m -8 60×10 or more Ω·m -8 more preferably 10×10 or less Ω·m -8 53×10 or more Ω·m -8 even more preferably. The volume resistivity of the material constituting the first film 56 is measured according to JIS C2525:1999 the side method.

[0041] As shown in FIG. 2A, when the vicinity of the plug placement hole 50 on the lower surface 23 of the ceramic substrate 20 is covered by the resin adhesive layer 40 on the lower surface 23 of the ceramic substrate 20, the lower surface 23 of the ceramic substrate 20 is not exposed, so the second film 57 may not be present. However, depending on the processing accuracy, the resin adhesive layer 40 may not sufficiently cover the lower surface 23 of the ceramic substrate 20, resulting in the exposure of the vicinity of the plug placement hole 50 on the lower surface 23 of the ceramic substrate 20. Furthermore, at least a part of the first film 56 may not contact the resin adhesive layer 40. Therefore, as shown in FIG. 2B, by previously covering the vicinity of the plug placement hole 50 on the lower surface 23 of the ceramic substrate 20 with the film 57, the discharge risk can be reduced. The film 57 may cover a part of the lower surface of the ceramic substrate 20 or the whole, but the film 57 is formed in a range (e.g., 1 to 10 mm in the direction perpendicular to each tangent at the inner peripheral edge of the plug placement hole 50 when the ceramic substrate 20 is observed from the lower surface 23 side) such that the lower surface 23 of the ceramic substrate 20 is not exposed in consideration of the processing accuracy of the resin adhesive layer 40, which is preferable in terms of cost-effectiveness. 23

[0042] ​The average thickness of the first film 56 covering the lower surface 55a of the dielectric plug 55 and the film 57 covering the lower surface 23 of the ceramic substrate 20 is preferably 0.5 μm or more, more preferably 1 μm or more, and even more preferably 20 μm or more in order to reduce the contact resistance. Also, the average thickness of the first film 56 and the second film 57 is preferably equal to or less than the thickness of the resin adhesive layer 40 so as not to protrude in the vertical direction from the resin adhesive layer 40, and more preferably 100 μm or less, and even more preferably 60 μm or less so as not to block the gas inlet of the plug. Therefore, the average thickness of the first film 56 and the second film 57 is preferably, for example, 0.5 μm or more and 100 μm or less, more preferably 1 μm or more and 60 μm or less, and even more preferably 20 μm or more and 50 μm or less. The average thickness of the first film 56 and the second film 57 is measured, for example, by cross-sectional observation using SEM. Specifically, using a scanning electron microscope (SEM), the thicknesses of the films at three locations are measured at equal intervals of 5 μm per field of view at a magnification of 3000 times, and the average value of the film thickness per field of view is calculated. The same measurement is performed for any five fields of view, and the average value of the film thicknesses in the five fields of view is taken as the measured value.

[0043] If the first film 56 and / or the second film 57 is electrically connected to the base plate 30 via the conductive connection portion 70 described later, the potential can be dropped to the same level as that of the base plate 30. Since the potential of the base plate is usually ground (GND), the potential at the lower surface 55a of the dielectric plug 55 can be dropped to ground. For this reason, the generation of discharge in the vicinity of the lower surface 55a of the dielectric plug 55 can be suppressed.

[0044] Examples of the materials constituting the first film 56 and the second film 57 include metals, carbon, conductive ceramics, etc. Composite materials of metals and ceramics are also included. Therefore, in one embodiment, the first film 56 and the second film 57 contain a metal, carbon, conductive ceramics, or a composite material of two or more of these. Examples of the metal include single metals selected from Au, Ag, Al, Ti, and Mo, alloys containing one or two or more of these, stainless steels such as SUS316L, and highly corrosion-resistant Ni alloys such as Hastelloy. Examples of the carbon include diamond-like carbon (DLC). Examples of the conductive ceramics include SiC, SiSiC, etc. In addition, organic components may remain in the first film 56 and the second film 57 in addition to the inorganic materials. Examples of the organic components include acrylic resins and epoxy resins. In addition to the above metals, inorganic materials such as glass may also be contained.

[0045] Examples of the method for forming the first film 56 on the lower surface 55a of the dielectric plug 55 and the method for forming the second film 57 on the lower surface 23 of the ceramic substrate 20 include thermal spraying, CVD method, PVD method (e.g., sputtering, vacuum evaporation, ionization evaporation, ion beam), dip method, and stamp method.

[0046] Referring to FIGS. 2A and 2B, a gas passage 60 for supplying gas to a gas passage portion 55c of a dielectric plug 55 through a base plate 30 and a resin adhesive layer 40 includes, for example, an adhesive layer through portion 64 that vertically penetrates the resin adhesive layer 40 to partition the gas passage 60, a gas distribution passage 62 that communicates with the adhesive layer through portion 64 and extends downward from the upper surface 31 of the base plate 30, and a gas supply passage 63 that communicates with the gas distribution passage 62 and supplies gas to the gas distribution passage 62. There is no particular limitation on the configuration of the gas supply passage 63. For example, one or more ring portions 63a in which the passage extends concentrically with the base plate 30 in plan view, and one or more gas introduction portions 63b that supply gas introduced from the lower surface 33 of the base plate 30 to the ring portions 63a may be provided. Also, the plurality of gas passages 60 and the plurality of plug arrangement holes 50 may be configured to communicate in a one-to-one correspondence. Other auxiliary passages (not shown) may be provided.

[0047] As shown in FIGS. 2A and 2B, at least a part of a film 56 covering the lower surface 55a of the dielectric plug 55 is in contact with the resin adhesive layer 40. There is no particular limitation on the contact location, but for example, it can contact the inner peripheral edge 64a of the adhesive layer through portion 64. By the first film 56 being in contact with the resin adhesive layer 40, or by the second film 57 being in contact with both the first film 56 and the resin adhesive layer 40, it is possible to suppress the occurrence of discharge between the lower surface 55a of the dielectric plug 55 and the resin adhesive layer 40. This is because the resin adhesive layer 40 is electrically conductive with the base plate 30. If the first film 56 is in contact with the resin adhesive layer 40, there is no particular limitation on the structure of the adhesive layer through portion 64, but it is preferable if the adhesive layer through portion 64 is arranged such that a portion overlapping the first film 56 occurs when viewed virtually from above in perspective, as they are likely to come into contact. In the present embodiment, as can be understood from the partial enlarged view of FIG. 1 and FIGS. 2A, a location 64b (in the present embodiment, the lower end of the adhesive layer through portion 64) of the inner peripheral edge 64a of the adhesive layer through portion 64 having the smallest opening diameter when viewed virtually from above is located inside a region defined by the outer peripheral edge 56a of the first film 56 covering the lower surface 55a of the dielectric plug 55.

[0048] Also, as can be understood from the partial enlarged view of FIG. 1 and FIGS. 2A, when viewed virtually in perspective from above, the inner peripheral edge 31a of the gas distribution path 62 on the upper surface 31 of the base plate 30 is located inside the region partitioned by the outer peripheral edge 56a of the first film 56 that covers the lower surface 55a of the dielectric plug 55. As a result, the diameter of the adhesive layer through-hole 64 can be reduced, making it easier for at least a part of the first film 56 that covers the lower surface 55a of the dielectric plug 55 to come into contact with the resin adhesive layer 40.

[0049] As shown in FIGS. 2A and 2B, the adhesive layer through-hole 64 is a hole that vertically penetrates the resin adhesive layer 40 and is a gas passage from the lower surface 41 to the upper surface 42 of the resin adhesive layer 40. In the present embodiment, a plurality (here, 36) of adhesive layer through-holes 64 are provided and are arranged in a one-to-one correspondence with the plug placement holes 50.

[0050] The inner peripheral edge 64a of the adhesive layer through-hole 64 may extend in the vertical direction, but as shown in FIGS. 2A and 2B, it is preferably configured such that the gas passage widens upward. As a result, an inclined surface is formed on the inner peripheral edge 64a of the adhesive layer through-hole 64. When joining the base plate 30 and the ceramic substrate 20 via the resin adhesive layer 40, there is a risk that the resin adhesive layer 40 will bulge greatly toward the lower surface 55a of the dielectric plug 55 and cover the gas inlet on the lower surface 55a, reducing the gas flow rate flowing through the lower surface 55a of the dielectric plug 55. However, having this configuration can reduce the risk of the resin adhesive layer 40 covering the gas inlet on the lower surface 55a of the dielectric plug 55.

[0051] The conductive connection part 70 has an upper end 70a that is electrically conductive to the first film 56 and a lower end 70b that is electrically conductive to the base plate 30, and is provided in the gas passage 60. Typically, the upper end 70a of the conductive connection part 70 contacts the first film 56, and the lower end 70b of the conductive connection part 70 contacts the base plate 30. The connection part 70 installed at one location may be composed of a single member or a plurality of members.

[0052] In this embodiment, the connecting portion 70 is provided separately from the base plate 30, and its lower surface is in contact with the base plate 30. More specifically, the connecting portion 70 is provided so as to straddle the inside of the adhesive layer through-hole 64 and the inside of the gas distribution path 62 in the gas passage 60, and is in contact with the base plate 30 at the bottom surface 62a of the gas distribution path 62. By contacting the base plate 30, the connecting portion 70 is electrically conductive with the base plate 30. A plurality (here, 36) of connecting portions 70 are provided and are arranged in a one-to-one correspondence with the dielectric plugs 55. In this embodiment, the connecting portion 70 is a coil spring having a circular shape in plan view. The connecting portion 70 may be an integral member instead of being separate from the base plate 30. For example, the connecting portion 70 may be a part of the base plate 30. In this case, the connecting portion 70 can be formed as a protrusion provided on the upper surface of the bottom surface 62a of the gas distribution path 62.

[0053] The connecting portion 70 may be configured such that the flow of the gas passing through the gas passage 60 is not blocked, and the gas may not be able to pass through the inside of the connecting portion 70. Further, the connecting portion 70 may have a structure through which the gas can pass inside. In this case, the gas in the gas passage 60 can pass through the inside of the connecting portion 70 and flow into the plug placement hole 50. Examples of the member through which the gas can pass inside include a conductive mesh, a mass of conductive fibers, and a conductive porous body.

[0054] The connecting portion 70 is preferably made of a material having a lower volume resistivity than the material constituting the dielectric plug 55. Examples of the material constituting the connecting portion 70 include inorganic materials such as metals, carbon, and conductive ceramics. Therefore, in one embodiment, the connecting portion 70 contains a metal, carbon, conductive ceramics, or a composite material of two or more of these. A composite material of a metal and ceramics is also included. Examples of the metal include simple metals selected from Au, Ag, Al, Ti, and Mo, or alloys containing one or more of these, stainless steels such as SUS316L, highly corrosion-resistant Ni alloys such as Hastelloy, and steel. Examples of the carbon include diamond-like carbon (DLC). Examples of the conductive ceramics include SiC and SiSiC. When the connecting portion 70 is a conductive mesh, the mesh opening may be 0.062 mm (250 mesh) to 0.154 mm (100 mesh). When the connecting portion 70 is a mass of conductive fibers, examples include steel wool, carbon felt, porous metal obtained by sintering Ti fibers or Al powder, and the like. When the connecting portion 70 is a conductive porous body, the porosity can be, for example, 10 to 80% when measured by the mercury intrusion method in accordance with JIS R1655:2003.

[0055] The connecting part 70 is preferably a member having elasticity. For example, the above-described conductive mesh and the mass of conductive fibers are also examples of members having elasticity. When the connecting part 70 has a directionality in its expansion and contraction, it is preferably expandable and contractible at least in the vertical direction. The connecting part 70 is preferably pressed against the first film 56 on the lower surface 55a of the dielectric plug 55 and compressed. In the present embodiment, the connecting part 70 is a member having elasticity, and the connecting part 70 is pressed against the first film 56 on the lower surface 55a of the dielectric plug 55, so that it is vertically compressed between the dielectric plug 55 and the base plate 30. As a member having elasticity in the vertical direction, an elastic body such as a spring (e.g., a coil spring) can also be used. When it is an elastic body, when it is pressed against the first film 56 on the lower surface 55a of the dielectric plug 55 and compressed, it has the effect of pushing up the lower surface 55a of the dielectric plug 55, and the connecting part 70 can be surely brought into contact with the first film 56 provided on the lower surface 55a of the dielectric plug 55. Further, when the second film 57 is provided on the lower surface 23 of the ceramic substrate 20, it may be pressed against the second film 57 on the lower surface 23 of the ceramic substrate 20 and compressed. However, in this case, in order to exhibit the discharge suppressing effect, it is necessary that the first film 56 provided on the lower surface 55a of the dielectric plug 55 and the second film 57 provided on the lower surface 23 of the ceramic substrate 20 are in contact with each other. In this case, it is not necessary for the connecting part 70 to be in direct contact with the first film 56. This is because the connecting part 70 is electrically connected to the first film 56 via the second film 57.

[0056] In the above-described embodiment, a lift pin hole penetrating the member 10 for a semiconductor manufacturing apparatus may be provided. The lift pin hole is a hole for inserting a lift pin for moving the wafer W up and down with respect to the upper surface 21 of the ceramic substrate 20. The lift pin holes are provided at three positions when the wafer W is supported by, for example, three lift pins.

[0057] In the member for a semiconductor manufacturing apparatus according to the embodiment described in detail above, an effect of suppressing discharge generated between the wafer and the base plate, particularly discharge generated in the vicinity of the joint between the ceramic substrate and the base plate in the gas passage portion penetrating the ceramic substrate in the vertical direction, can be obtained. For example, the high-frequency (RF) power supply connected to the base plate can be increased in power. Further, there is a desire to increase the gas pressure of the backside gas for the purpose of further enhancing the efficiency of heat conduction between the wafer and the ceramic substrate. However, generally, when the gas pressure is increased, discharge is likely to occur. However, in the member 10 for a semiconductor manufacturing apparatus of the present embodiment, discharge is less likely to occur even when the gas pressure is increased.

[0058] <2. Method of using the member for a semiconductor manufacturing apparatus> Next, a method of using the member 10 for a semiconductor manufacturing apparatus configured in this way will be exemplarily described. First, with the member 10 for a semiconductor manufacturing apparatus installed in a chamber (not shown), the wafer W is placed on the upper surface 21 of the ceramic substrate 20. Then, the inside of the chamber is depressurized by a vacuum pump and adjusted to a predetermined degree of vacuum, and a voltage is applied to the electrode 22 of the ceramic substrate 20 to generate an electrostatic adsorption force, and the wafer W is adsorbed and fixed to the wafer placement surface (specifically, the upper surface of the seal band 21a or the upper surface of the small protrusion 21b).

[0059] Next, the inside of the chamber is set to a reaction gas atmosphere at a predetermined pressure (for example, several tens to several hundreds of Pa). In this state, a high-frequency voltage such as an RF voltage is applied between an upper electrode (not shown) provided on the ceiling portion inside the chamber and the base plate 30 of the member 10 for a semiconductor manufacturing apparatus to generate plasma. The surface of the wafer W is processed by the generated plasma. A refrigerant circulates in the refrigerant flow path 32 of the base plate 30. A backside gas is introduced into the gas introduction portion 63b of the gas passage 60 from a gas cylinder (not shown). As the backside gas, a heat conduction gas (for example, He gas or the like) can be used. The backside gas introduced into the gas introduction portion 63b is distributed through the ring portion 63a and the gas distribution path 62 to a plurality of plug arrangement holes 50 and supplied and enclosed in the space between the back surface of the wafer W and the reference surface 21c of the wafer placement surface. Due to the presence of this backside gas, heat conduction between the wafer W and the ceramic substrate 20 is efficiently performed.

[0060] Further, since the dielectric plug 55 is provided in the plug arrangement hole 50, discharge in the plug arrangement hole 50 can be suppressed. When there is no dielectric plug 55, as gas molecules are ionized by the application of an RF voltage, the electrons generated collide with other gas molecules and accelerate, resulting in glow discharge and then arc discharge. However, when there is the dielectric plug 55, the electrons hit the dielectric plug 55 before colliding with other gas molecules, so the discharge is suppressed.

[0061] <3. Manufacturing Method of Member for Semiconductor Manufacturing Apparatus> Next, a manufacturing method of the member 10 for a semiconductor manufacturing apparatus will be exemplarily described with reference to FIG. 3. FIG. 3 is a manufacturing process diagram of the member 10 for a semiconductor manufacturing apparatus according to an embodiment of the present invention. Here, a case where the base plate 30 is manufactured using MMC will be exemplified. First, a ceramic substrate 20 incorporating electrodes 22 is manufactured (FIG. 3A). The manufacturing procedure of the ceramic substrate 20 is as follows. A ceramic compact incorporating electrodes 22 is manufactured. The ceramic compact may be manufactured by laminating a plurality of tape compacts, may be manufactured by a mold casting method, or may be manufactured by pressing ceramic powder. Next, the ceramic substrate 20 is obtained by hot press firing the ceramic compact. Subsequently, plug placement holes 50 are formed in the ceramic substrate 20 (FIG. 3B). The plug placement holes 50 are formed so as to penetrate the ceramic substrate 20 in the vertical direction while avoiding the electrodes 22.

[0062] Next, a dielectric plug 55 is embedded in the plug placement holes 50 (FIG. 3C). As a method of embedding the dielectric plug 55 in the plug placement holes 50, for example, a method of press-fitting the dielectric plug 55 formed by pre-firing or the like into the plug placement holes 50 can be mentioned. Alternatively, a male screw portion is formed on the outer peripheral surface of the dielectric plug 55 formed by pre-firing or the like, a female screw portion is formed on the inner peripheral surface of the plug placement holes 50, and the dielectric plug 55 is screwed into the plug placement holes 50 and inserted, and the male screw portion of the dielectric plug 55 and the female screw portion of the plug placement holes 50 are screwed together to mount the dielectric plug 55. Further, a paste-like ceramic mixture, which is a precursor of the dielectric plug 55, may be injected into the plug placement holes 50 of the ceramic substrate 20 and fired to form the dielectric plug 55. As described above, the method of covering the lower surface 55a of the dielectric plug 55 with the first film 56 includes a sputtering method or the like. The first film 56 may be formed before the dielectric plug 55 is embedded in the plug placement holes 50, or may be formed after the embedding.

[0063] Separate from the ceramic substrate 20, a metal disk member 81 is prepared (Fig. 3D). Then, by machining, grooves and holes for the gas passage 60 and the refrigerant flow path 32 are appropriately formed in these metal disk members 81 (Fig. 3E).

[0064] Subsequently, the conductive connecting portion 70 is inserted into the through-hole 73 that becomes the gas distribution path 62 (Fig. 3F). In this case, for example, in a state before contacting the first film 56 that covers the lower surface 55a of the dielectric plug 55 (before compression of the connecting portion 70), it is preferable to arrange the connecting portion 70 such that the upper end 70a of the connecting portion 70 protrudes above the upper surface 31 of the base plate 30. In this way, it is easy to press the connecting portion 70 when bringing the connecting portion 70 into contact with the first film 56.

[0065] Subsequently, the upper surface 31 of the base plate 30 and the lower surface of the ceramic substrate 20 are bonded and adhered together with a thermosetting resin adhesive sheet (Fig. 3G). A method of bonding and adhering the upper surface 31 of the base plate 30 and the lower surface of the ceramic substrate 20 with a thermosetting resin adhesive sheet will be specifically described. First, a thermosetting resin adhesive sheet provided with an adhesive layer through-hole at a predetermined position is bonded to the upper surface 31 of the base plate 30, and then the ceramic substrate 20 is placed thereon. By heating and pressurizing this laminate in an autoclave, the thermosetting resin adhesive sheet is cured and the adhesion is completed. After that, through appropriate processes such as shaping the overall shape, the member 10 for a semiconductor manufacturing apparatus is completed.

Explanation of Reference Numerals

[0066] 10: Member for semiconductor manufacturing apparatus 20: Ceramic substrate 21: Upper surface 21a: Seal band 21b: Small protrusion 21c: Reference plane 22: Electrode 23: Lower surface 30: Base plate 31: Upper surface 31a: Inner peripheral edge 32: Refrigerant flow path 33: Below 40: Resin adhesive layer 41: Below 42: Above 50: Plug placement hole 50a: Inner peripheral surface 55: Dielectric plug 55a: Below 55b: Outer peripheral surface 55c: Gas passage part 55d: Above 56: First film 57: Second film 56a: Outer peripheral edge 60: Gas passage 62: Gas distribution path 62a: Bottom surface 63: Gas supply path 63a: Ring part 63b: Gas introduction part 64: Adhesive layer through-hole 64a: Inner peripheral edge 64b: Location with the smallest opening diameter 70: Connecting part 70a: Upper end 70b: Lower end 73: Through-hole 81: Disk member

Claims

1. A ceramic substrate having an upper surface for placing a wafer and a lower surface opposite to the upper surface, A plug placement hole penetrating the ceramic substrate in the vertical direction, A dielectric plug embedded in the plug placement hole, the dielectric plug having a lower surface and a gas passage portion penetrating the dielectric plug, A first film covering at least a part of the lower surface of the dielectric plug and made of a material having a lower volume resistivity than the material constituting the dielectric plug, A conductive base plate adhesively bonded to the lower surface of the ceramic substrate via a resin adhesive layer, A gas passage for supplying gas to the gas passage portion of the dielectric plug through the base plate and the resin adhesive layer, A conductive connecting portion provided in the gas passage, having an upper end electrically connected to the first film and a lower end electrically connected to the base plate, Comprising, At least a part of the first film is in contact with the resin adhesive layer, or at least a part of the lower surface of the ceramic substrate is covered with a second film made of a material having a lower volume resistivity than the material constituting the ceramic substrate, and at least a part of the second film is in contact with the resin adhesive layer and in contact with the first film, A member for a semiconductor manufacturing apparatus.

2. The member for a semiconductor manufacturing apparatus according to claim 1, wherein at least a part of the first film is in contact with the resin adhesive layer.

3. At least a part of the lower surface of the ceramic substrate is covered with a second film made of a material having a lower volume resistivity than the material constituting the ceramic substrate, and at least a part of the second film is in contact with the resin adhesive layer and in contact with the first film. The member for a semiconductor manufacturing apparatus according to claim 1 or 2.

4. The connecting portion has a stretchable member, and the stretchable member is pressed against the first film on the lower surface of the dielectric plug and compressed. The member for a semiconductor manufacturing apparatus according to claim 1 or 2.

5. The connecting portion has a stretchable member, and the stretchable member is pressed against the second film on the lower surface of the ceramic substrate and compressed. The member for a semiconductor manufacturing apparatus according to claim 1 or 2.

6. The member for a semiconductor manufacturing apparatus according to claim 1 or 2, wherein both the material constituting the dielectric plug and the material constituting the ceramic substrate contain one or more selected from aluminum oxide, aluminum nitride, quartz, and zirconia.

7. The member for a semiconductor manufacturing apparatus according to claim 1 or 2, wherein the first film on the lower surface of the dielectric plug contains a metal, carbon, a conductive ceramic, or a composite material of two or more of these.

8. The member for a semiconductor manufacturing apparatus according to claim 1 or 2, wherein the second film on the lower surface of the ceramic substrate contains a metal, carbon, a conductive ceramic, or a composite material of two or more of these.

9. The member for a semiconductor manufacturing apparatus according to claim 1 or 2, wherein the dielectric plug is an inorganic dielectric plug having a dense outer peripheral surface, and the outer peripheral surface is embedded in the plug placement hole so as to directly fit with the inner peripheral surface of the plug placement hole.

10. The member for a semiconductor manufacturing apparatus according to claim 1 or 2, wherein the inner peripheral edge of the through-hole of the resin adhesive layer partitioning the gas passage is configured such that the gas passage widens upward.

11. The member for a semiconductor manufacturing apparatus according to claim 9, wherein the inner peripheral surface of the plug placement hole that fits with the dense outer peripheral surface of the dielectric plug is dense.

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