Member for semiconductor manufacturing apparatus

Abstract

This invention addresses the problem of providing a member for a semiconductor manufacturing apparatus, in which a plug can be embedded into a plug disposition hole with high positioning accuracy even without using an adhesive. The member for a semiconductor manufacturing apparatus comprises: a ceramic substrate that has an upper surface and a lower surface for placing a wafer; a plug disposition hole that penetrates the ceramic substrate in an up-down direction and has a tapered inner circumferential surface having an upper opening area larger than a lower opening area; a ceramic plug that has a dense outer circumferential surface and a gas flow path penetrating the plug, and is embedded such that the dense outer circumferential surface of the plug is directly fitted to the inner circumferential surface of the plug disposition hole; a conductive base plate bonded to the lower surface of the ceramic substrate via a bonding layer; and a gas supply path that passes through the base plate and the bonding layer to supply gas to the gas flow path of the ceramic plug.

Description

Semiconductor manufacturing equipment components

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

[0002] Conventionally, semiconductor manufacturing equipment components have been known that are used for holding wafers, controlling their temperature, transporting them, etc. These types of semiconductor manufacturing equipment components are also called wafer mounting tables, electrostatic chucks, susceptors, etc., and generally have the function of applying electrostatic attraction power to a built-in electrode to attract the wafer by electrostatic force, and some are also known to have the function of controlling the wafer temperature by flowing gas between the wafer mounting surface and the wafer to be attracted.

[0003] A known component for semiconductor manufacturing equipment includes, for example, a ceramic substrate having an upper surface for placing a wafer thereon, a gas passage that passes through the ceramic substrate in the vertical direction, and a conductive base plate bonded to the lower surface of the ceramic substrate.

[0004] In such semiconductor manufacturing equipment components, a large potential difference may occur between the wafer and the base plate, which can lead to discharge (dielectric breakdown) between the wafer and the base plate through the gas passage. For this reason, various techniques for placing a plug in the gas passage have been investigated to suppress discharge. The plug is often made of a porous material. Without the plug, for example, when an RF voltage is applied, ionizing gas molecules, resulting in electrons that accelerate and collide with other gas molecules, resulting in a glow discharge and eventually an arc discharge. However, with the plug, the electrons strike the plug before colliding with other gas molecules, suppressing discharge.

[0005] Patent Document 1 proposes a plug having a gas flow path portion that bends and penetrates a dense body portion in the thickness direction. It also proposes making at least a portion of the entire length of the gas flow path portion insulating and porous. Patent Document 1 also describes fixing the plug to the plug insertion hole with an adhesive material of insulating resin such as silicone resin, epoxy resin, or acrylic resin.

[0006] Patent Document 2 discloses an electrostatic chuck comprising: a ceramic dielectric substrate having a first main surface on which an object to be attracted is placed and a second main surface opposite the first main surface; a base plate supporting the ceramic dielectric substrate and having a gas inlet passage; and a first porous portion disposed between the base plate and the first main surface of the ceramic dielectric substrate and facing the gas inlet passage, wherein the ceramic dielectric substrate has a first hole portion located between the first main surface and the first porous portion, the first porous portion having a porous portion with a plurality of holes and a first dense portion denser than the porous portion, and when projected onto a plane perpendicular to a first direction from the base plate toward the ceramic dielectric substrate, the first dense portion overlaps with the first hole portion, but the porous portion does not overlap with the first hole portion. Patent Document 2 discloses an adhesive member provided between the first porous portion and the ceramic dielectric substrate, and a silicone adhesive is described as the adhesive member.

[0007] Patent Document 3 describes an electrostatic chuck including: a ceramic dielectric substrate having a first main surface on which an object to be attracted is placed and a second main surface opposite the first main surface; a base plate supporting the ceramic dielectric substrate and having a gas inlet passage; and a first porous portion provided between the base plate and the first main surface of the ceramic dielectric substrate and facing the gas inlet passage, wherein the first porous portion has a plurality of sparse portions having a plurality of holes and a dense portion having a density higher than a density of the sparse portions, each of the plurality of sparse portions extending in a first direction from the base plate toward the ceramic dielectric substrate, the dense portion being located between the plurality of sparse portions, the sparse portion having the holes and a wall portion provided between the holes, and a minimum value of a dimension of the wall portion being smaller than a minimum value of a dimension of the dense portion in a second direction substantially perpendicular to the first direction. According to Patent Document 3, when the first porous portion and the ceramic dielectric substrate are integrated by sintering, the strength of the electrostatic chuck can be improved compared to when an adhesive is provided between them, and it is also described that deterioration of the electrostatic chuck due to corrosion, erosion, etc. of the adhesive does not occur.

[0008] Patent Document 4 describes an invention aimed at providing a holding device capable of controlling the temperature of an object with high accuracy while reducing the occurrence of abnormal discharge. Specifically, the holding device described includes a ceramic substrate having a first surface for holding an object and a second surface opposite the first surface, a base member disposed on the second surface side of the ceramic substrate, the base member having a third surface opposite the ceramic substrate, and a bonding material disposed between the ceramic substrate and the base member, wherein (1) the ceramic substrate and the base member are formed with a flow path that allows a fluid to move between an outlet hole provided in the first surface and an inlet hole provided in the third surface, or (2) the ceramic substrate is formed with a flow path that allows a fluid to move between an outlet hole provided in the first surface and an inlet hole provided in the second surface, the flow path having a porous ceramic region, the porous ceramic region including a sparse region and a dense region having a lower porosity than the sparse region and disposed closer to the first surface than the sparse region. According to Patent Document 4, the porous ceramic region can be formed by preparing a cylindrical porous body M having a different porosity in the axial direction and fitting it into a large diameter portion provided at a predetermined connection portion during the manufacturing process of the ceramic substrate.

[0009] Patent Document 5 discloses a wafer mounting table including an insulating first porous portion disposed within a through-hole in a ceramic plate and an insulating second porous portion fitted in a recess on the ceramic plate side of a base plate so as to face the first porous portion. Gas supplied to a gas inlet passage passes through the second and first porous portions and flows into a space between a wafer mounting surface and a wafer, where it is used to cool the object. The existence of the first and second porous portions is described as ensuring a gas flow rate from the gas inlet passage to the wafer mounting surface while suppressing the occurrence of plasma-induced discharge (arc discharge) during wafer processing. Patent Document 5 also describes that integrating the first porous portion and the ceramic dielectric substrate by sintering them improves the strength of the electrostatic chuck compared to when an adhesive is provided between them, and also prevents deterioration of the electrostatic chuck due to corrosion or erosion of the adhesive.

[0010] JP 2022-119338 A JP 2022-31333 A JP 2019-165194 A JP 2022-176701 A JP 2020-72262 A

[0011] As described above, in order to suppress discharges occurring between the wafer and the base plate in semiconductor manufacturing equipment components, various technologies have been proposed to improve the structure near the plug disposed in the gas passage that penetrates the ceramic substrate in the vertical direction. It is also known that the use of an adhesive when fixing the plug to the gas passage prevents deterioration due to corrosion or erosion of the adhesive. However, the use of an adhesive tends to reduce the fixing strength of the plug, which leads to a problem of reduced vertical positioning accuracy when embedding the plug in the plug placement hole. For this reason, there is still room for improvement in technologies for embedding the plug in the plug placement hole with high positioning accuracy without using an adhesive.

[0012] In view of the above circumstances, an object of one embodiment of the present invention is to provide a member for a semiconductor manufacturing apparatus that allows a plug to be embedded in a plug placement hole with high positioning accuracy without using an adhesive.

[0013] The present inventors have conducted extensive research to solve the above problems and have created the present invention, which is exemplified below.

[0014] [Aspect 1] A semiconductor manufacturing equipment component comprising: a ceramic substrate having upper and lower surfaces for mounting a wafer; a plug placement hole penetrating the ceramic substrate in the vertical direction and having a tapered inner circumferential surface with an upper opening area larger than an area of ​​a lower opening; a ceramic plug having a dense outer circumferential surface and a gas flow path penetrating the plug, the ceramic plug being embedded in the plug placement hole so that the dense outer circumferential surface of the plug directly fits into the inner circumferential surface of the plug placement hole; a conductive base plate bonded to the underside of the ceramic substrate via a bonding layer; and a gas supply path that passes through the base plate and the bonding layer and supplies gas to the gas flow path of the ceramic plug. [Aspect 2] The semiconductor manufacturing equipment component according to Aspect 1, wherein the inner circumferential surface of the plug placement hole is inclined at an angle of 70° to 87° with respect to the lower opening. [Aspect 3] The semiconductor manufacturing equipment component according to Aspect 1 or 2, wherein the inner circumferential surface of the plug placement hole that fits into the dense outer circumferential surface of the ceramic plug is dense. [Aspect 4] A semiconductor manufacturing equipment member according to any one of Aspects 1 to 3, wherein the material constituting the ceramic plug and the material constituting the ceramic substrate both contain one or more selected from aluminum oxide and aluminum nitride. [Aspect 5] A semiconductor manufacturing equipment member according to any one of Aspects 1 to 4, wherein the porosity of the dense outer peripheral surface of the ceramic plug is 1% or less. [Aspect 6] A semiconductor manufacturing equipment member according to any one of Aspects 1 to 5, wherein the ceramic plug has a truncated conical outer shape. [Aspect 7] A semiconductor manufacturing equipment member according to any one of Aspects 1 to 6, wherein the thickness from the upper opening to the lower opening of the ceramic substrate is 1 mm or more. [Aspect 8] A punching strength of 1 N / mm when the ceramic plug is punched from the lower opening to the upper opening of the plug placement hole according to the punching test method described herein. 2 The semiconductor manufacturing equipment member according to any one of Aspects 1 to 7.

[0015] A semiconductor manufacturing equipment component according to one embodiment of the present invention has a plug placement hole with a tapered inner circumferential surface, in which the area of ​​the upper opening is larger than the area of ​​the lower opening. Because this plug placement hole functions as a stopper, when the plug is embedded in the plug placement hole, it is easy for the plug to stop at a predetermined height position in the plug placement hole. In other words, this semiconductor manufacturing equipment component has the effect of enabling the plug to be embedded in the plug placement hole with high positioning accuracy. Furthermore, because the plug placement hole has this structure, the plug is difficult to remove downward, but is relatively easy to remove upward. This also makes it easy to replace the plug. Furthermore, the increased creepage distance also has the effect of suppressing discharge.

[0016] Furthermore, by appropriately setting the inclination angle of the inner peripheral surface of the plug placement hole and using a plug having an outer peripheral surface that can fit into the plug placement hole, it is possible to prevent the plug from being pulled out too easily in the upward direction.

[0017] Fig. 1 is a schematic longitudinal sectional view of a semiconductor manufacturing equipment member according to one embodiment of the present invention. Fig. 2 is a partially enlarged view of Fig. 1. Fig. 2 is a schematic plan view of a ceramic substrate according to one embodiment. Fig. 3 is a schematic longitudinal sectional view of a semiconductor manufacturing equipment member according to another embodiment of the present invention. Fig. 4 is a schematic longitudinal sectional view of a compression testing machine used in a punching test. Fig. 5 is a manufacturing process diagram of a semiconductor manufacturing equipment member according to one embodiment of the present invention.

[0018] 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 that appropriate design changes, improvements, and the like may be made based on the common knowledge of those skilled in the art without departing from the spirit of the present invention. Furthermore, in this specification, "upper" and "lower" are used for convenience to represent the relative positional relationship when the semiconductor manufacturing equipment component is placed on a horizontal surface with the base plate facing downwards, and do not represent absolute positional relationships. Therefore, depending on the orientation of the semiconductor manufacturing equipment component, "upper" and "lower" may become "lower" and "upper," "left" and "right," or "front" and "rear."

[0019] 1 and 2 , a semiconductor manufacturing equipment member 10 according to one embodiment of the present invention includes: a ceramic substrate 20 having an upper surface 21 for mounting a wafer thereon and a lower surface 23 opposite to the upper surface 21; a plug placement hole 50 that vertically penetrates the ceramic substrate 20 and has a tapered inner circumferential surface 50 a with an upper opening 50 b having an area larger than an area of ​​a lower opening 50 c; a ceramic plug 55 that has a dense outer circumferential surface and a gas flow path that penetrates the plug, and is embedded in the plug placement hole 50 such that the dense outer circumferential surface 55 a of the plug 55 directly fits into the inner circumferential surface 50 a; a conductive base plate 30 bonded to the lower surface 23 of the ceramic substrate 20 via a bonding layer 40; and a gas supply path 60 that passes through the base plate 30 and the bonding layer 40 to supply gas to the gas flow path 55 d of the ceramic plug 55.

[0020] The ceramic substrate 20 can be, for example, a circular plate (e.g., 300-400 mm in diameter) made of ceramic, such as alumina sintered body or aluminum nitride sintered body. The thickness of the ceramic substrate 20 is not limited, but from the viewpoint of increasing the fixing strength of the plug 55, the thickness from the upper opening 50b to the lower opening 50c is preferably 1 mm or more. Furthermore, from the viewpoint of reducing heat transfer and manufacturing costs of the ceramic substrate 20, the thickness is preferably 5 mm or less, more preferably 3 mm or less, and even more preferably 2 mm or less. Therefore, the thickness from the upper opening 50b to the lower opening 50c is, for example, preferably 1-5 mm, more preferably 1-3 mm, and even more preferably 1-2 mm. Here, the thickness from the upper opening 50b to the lower opening 50c refers to the distance D from the center of gravity G1 of the upper opening 50b to the center of gravity G2 of the lower opening 50c. The height of the upper opening 50b is equal to the height of the reference plane 21c of the upper surface 21 of the ceramic substrate 20, which will be described later. The height of the lower opening 50 c is equal to the height of the lower surface 23 of the ceramic substrate 20 .

[0021] The upper surface 21 of the ceramic substrate 20 has a wafer mounting surface on which a wafer W is mounted. The ceramic substrate 20 incorporates an electrode 22. As shown in FIG. 3 , an annular seal band 21a is formed on the upper surface 21 of the ceramic substrate 20 along its outer edge, and multiple 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, but may be, for example, a cylindrical or rectangular column. The seal band 21a and the small protrusions 21b preferably have the same height, which is, for example, 5 to 100 μm, 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 source via a power supply member (not shown). A low-pass filter may be disposed along the power supply member. The power supply member is electrically insulated from the bonding layer 40 and the base plate 30. When a DC voltage is applied to this electrode 22, the wafer W is attracted and fixed to the wafer mounting surface (specifically, the upper surfaces of the seal bands 21a and the small protrusions 21b) by electrostatic attraction, and when the application of the DC voltage is stopped, the attracting and fixing of the wafer W to the wafer mounting surface is released. Note that the portion of the upper surface 21 of the ceramic substrate 20 on which the seal bands 21a and the small protrusions 21b are not provided is referred to as the reference surface 21c.

[0022] Instead of or in addition to the electrostatic electrode, a heater electrode (resistance heating element) may be built in as the electrode 22. In this case, a heater power supply is connected to the heater electrode. The ceramic substrate 20 may have one layer of electrodes built in, or two or more layers of electrodes built in with a gap between them.

[0023] The conductive base plate 30 is a circular plate (having the same diameter as or larger than the ceramic substrate 20) with good electrical and thermal conductivity. A refrigerant flow path 32 through which a refrigerant circulates may be formed within the base plate 30. The refrigerant flowing through the refrigerant flow path 32 is preferably a liquid, preferably electrically insulating. Examples of electrically insulating liquids include a fluorine-based inert liquid. For example, the refrigerant flow path 32 can be formed in a single stroke across the entire base plate 30 in a plan view from one end (inlet) to the other end (outlet). One end and the other end of the refrigerant flow path 32 are connected to a supply port and a recovery port, respectively, of an external refrigerant device (not shown). The refrigerant supplied from the supply port of the external refrigerant device to one end of the refrigerant flow path 32 passes through 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, and is temperature-adjusted before being supplied again from the supply port to one end of the refrigerant flow path 32. The base plate 30 is connected to a radio frequency (RF) power source and can also be used as an RF electrode.

[0024] The base plate 30 may be made of a metal material or a composite material of metal and ceramic. Metal materials include Al, Ti, Mo, W, and alloys thereof. Metal-ceramic composite materials include metal matrix composites (MMCs) and ceramic matrix composites (CMCs). Specific examples of such composite materials include a material containing Si, SiC, and Ti (also known as SiSiCTi), a porous SiC material impregnated with Al and / or Si, and a composite material of AlO and TiC. A porous SiC material impregnated with Al is called AlSiC, and a porous SiC material impregnated with Si is called SiSiC. It is preferable to select a material for the base plate 30 with a thermal expansion coefficient close to that of the ceramic substrate 20. For example, if the ceramic substrate 20 is made of alumina, the base plate is preferably made of SiSiCTi or AlSiC.

[0025] As shown in FIG. 2 , the upper surface 31 of the base plate 30 is bonded to the lower surface 23 of the ceramic substrate 20 via a bonding layer 40. The bonding layer 40 is formed, for example, by thermal compression bonding (TCB). TCB is a known method in which a metal bonding material is sandwiched between two components to be bonded and the two components are pressure-bonded while heated to a temperature below the solidus temperature of the metal bonding material. The bonding layer 40 can be formed, for example, by a metal bonding layer using an Al-Mg bonding material or an Al-Si-Mg bonding material. The bonding layer 40 may also be formed from solder or a metal brazing material. Furthermore, the bonding layer 40 may be formed, instead of a metal bonding layer, by a resin adhesive layer. Examples of materials for the resin adhesive layer include a silicone resin adhesive, an epoxy resin adhesive, and an acrylic resin adhesive. To improve the uniformity of the thickness of the resin adhesive layer, 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] The bonding layer 40 has a through hole 42. The through hole 42 is provided at a position facing the large diameter portion 34a of the gas hole 34. The through hole 42 is provided coaxially with the large diameter portion 34a, and the diameter of the through hole 42 may be the same as the diameter of the large diameter portion 34a. In this specification, "matching" includes not only a perfect match but also a substantial match (for example, within a tolerance range) (the same applies below). In this embodiment, the gas hole 34 and the through hole 42 correspond to a gas supply path 60 that passes through the base plate 30 and the bonding layer 40 and supplies gas to the gas flow path 55d of the ceramic plug 55.

[0027] As shown in FIGS. 1 and 2 , the plug arrangement hole 50 is a hole that penetrates the ceramic substrate 20 in the vertical direction. The plug arrangement hole 50 is a gas passage that extends 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 arrangement hole 50 (meaning the circular equivalent diameter when the cross section of the plug arrangement hole is not circular) is not limited, but can be, for example, within a range of 1 to 5 mm at any height position, and can typically be within a range of 3 to 4 mm. The plug arrangement hole 50 may have a tapered inner circumferential surface 50a whose diameter decreases from top to bottom and whose upper opening 50b has a larger area than that of its lower opening 50c. By having such a tapered inner circumferential surface 50a, the plug 55 is more likely to stop at a predetermined height position in the plug arrangement hole 50 when the plug 55 is embedded in the plug arrangement hole 50, thereby enabling the plug to be embedded in the plug arrangement hole with high positioning accuracy. In addition, while the plug is difficult to remove downward, it is relatively easy to remove upward, which makes it easier to replace the plug. Furthermore, the longer creepage distance also has the effect of suppressing discharge. The plug mounting hole 50 can have a space in the shape of a truncated cone or a truncated pyramid, for example.

[0028] The inclination angle α of the inner circumferential surface 50a of the plug arrangement hole 50 with respect to the lower opening 50c is preferably 70° or more, and more preferably 75° or more, from the viewpoints of increasing the fixing strength of the plug 55 and preventing the volume of the plug 55 from becoming excessively large to ensure space for arranging electrodes around it. Furthermore, the inclination angle α is preferably 87° or less, and more preferably 85° or less, from the viewpoints of improving the positioning accuracy of the plug in the height direction when the plug 55 is press-fitted downward into the plug arrangement hole 50, making the plug 55 easier to replace, and lengthening the creepage distance to suppress discharge. Therefore, the inclination angle α is preferably, for example, 70° to 87°, and more preferably 75° to 85°.

[0029] As shown in FIG. 3 , the semiconductor manufacturing equipment component according to this embodiment includes multiple plug placement holes 50 (six in this example). Ceramic plugs 55 are embedded in the plug placement holes 50. The ceramic plugs 55 have gas flow paths 55d penetrating the interior of the ceramic plug 55. In one embodiment, the gas flow path 55d has one opening on the lower surface 55c of the plug 55 and the other opening on the upper surface 55b, penetrating the interior of the plug 55 in the vertical direction. In another embodiment, the gas flow path 55d has one opening on the lower surface 55c of the plug 55 and the other opening on the outer peripheral surface 55a, penetrating the interior of the plug 55. The outer peripheral surface 55a of the ceramic plug 55 and the inner peripheral surface 50a of the plug placement hole 50 are directly fitted to each other without the use of adhesive. This direct fit prevents voids from forming between the ceramic plug 55 and the plug placement hole 50 due to deterioration caused by corrosion or erosion of the adhesive. This provides the advantage of being able to suppress discharge caused by deterioration of the adhesive and detachment of the ceramic plug 55. Furthermore, the natural frequency of the ceramic substrate 20 in which the plug 55 is embedded in the plug placement hole 50 can be 1000 kHz or higher. In this case, since the natural frequency is on the high-frequency side, there is also the advantage of being able to prevent detachment of the plug due to vibrations such as transportation vibrations on the low-frequency side.

[0030] 1 and 2 , when observing a longitudinal cross section obtained by cutting the ceramic substrate 20 in the thickness direction, from the viewpoint of improving the fixing strength of the ceramic plug 55, it is preferable that the inner circumferential surface 50 a of the ceramic plug 55 contacts the outer circumferential surface 55 a of the ceramic plug 55 in a parallel positional relationship. In other words, the outer circumferential surface 55 a of the ceramic plug 55 has the same inclination angle as the inner circumferential surface 50 a of the plug placement hole 50. Therefore, in a preferred embodiment, the ceramic plug has an outer shape that is the same shape as the plug placement hole (e.g., a truncated cone or a truncated pyramid). This increases the area of ​​contact between the inner circumferential surface 50 a of the ceramic plug 55 and the outer circumferential surface 55 a of the ceramic plug 55, thereby achieving high fixing strength.

[0031] An example of a direct fitting method is to embed the ceramic plug 55 by press-fitting it into the plug placement hole 50. In this case, to obtain the desired fixing strength, it is preferable that the horizontal cross-sectional diameter of the ceramic plug 55 at any height position before press-fitting be slightly larger (for example, by approximately 5 to 20 μm in circle equivalent diameter) than the horizontal cross-sectional diameter of the plug placement hole 50 at the same height position. Another example of a direct fitting method is to thread a male thread portion provided on the outer peripheral surface 55 a of the ceramic plug 55 into a female thread portion provided on the inner peripheral surface 50 a of the plug placement hole 50. Furthermore, the ceramic plug 55 may be formed by injecting a paste-like ceramic mixture, which serves as a precursor of the ceramic plug 55, into the plug placement hole 50 of the ceramic substrate 20 and firing it.

[0032] The ceramic plug 55 preferably has a dense outer peripheral surface 55a. If the ceramic plug 55 has a dense outer peripheral surface 55a, when the ceramic plug 55 is directly fitted to the inner peripheral surface 50a of the plug placement hole 50, sufficient frictional force acts, thereby increasing the fixing strength of the ceramic plug 55. A dense outer peripheral surface 55a means that the porosity of the outer peripheral surface 55a is 5% or less. The porosity of the outer peripheral surface 55a is preferably 1% or less, and more preferably 0.5% or less. The porosity of the outer peripheral surface 55a is measured by the following method. The ceramic plug 55 is cut so that a cross section perpendicular to the outer peripheral surface 55a of the ceramic plug 55 is exposed. Next, a portion of the cross section 100 μm thick from the outer peripheral surface 55a is observed at a magnification of 3000 times using a scanning electron microscope (SEM) to measure the porosity of the outer peripheral surface 55a to 2200 μm. 2The thickness of the SEM image is observed to determine the area ratio of pores observed in the thickness portion. Specifically, the SEM image is analyzed, and a threshold is determined using discriminant analysis (Otsu's binarization) based on the brightness distribution of the brightness data of the pixels in the image. 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 ceramic plug 55, and the average value of the five locations is taken as the porosity of the outer peripheral surface 55a of the ceramic plug 55.

[0033] Furthermore, when the outer peripheral surface 55a of the ceramic plug 55 is directly fitted to the inner peripheral surface 50a of the plug placement hole 50, the inner peripheral surface 50a of the plug placement hole 50 is also preferably dense in order to increase the frictional fixation strength of the ceramic plug 55. A dense inner peripheral surface 50a means that the porosity of the inner peripheral surface 50a is 5% or less. Therefore, the porosity of the inner peripheral surface 50a is preferably 1% or less, and more preferably 0.5% or less. Because the inner peripheral surface 50a is a portion of the ceramic substrate 20, the porosity value of the ceramic substrate 20 is herein 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 measured value is the average open porosity of five samples uniformly collected from the ceramic substrate 20.

[0034] The height position of the upper surface 55b of the ceramic plug 55 is not limited. Therefore, it may be the same height as the reference surface 21c of the ceramic substrate 20, or it may be a different height. However, it is preferable that the height position of the upper surface 55b of the ceramic plug 55 be the same height as the reference surface 21c. When the upper surface of the ceramic plug 55 is lower than the reference surface 21c, it is preferable to position 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 ceramic plug 55 is higher than the reference surface 21c, there are no particular limitations as long as it is lower than the upper surfaces of the small protrusions 21b and the outflow of gas from the ceramic plug 55 is not hindered.

[0035] There is no particular limitation on the height position of the lower surface 55c of the ceramic plug 55. Therefore, it may be at the same height as the lower surface 23 of the ceramic substrate 20, or it may be at a different height. For example, the lower surface 55c of the ceramic plug 55 may protrude downward from the lower surface 23 of the ceramic substrate 20, or the lower surface 55c of the ceramic plug 55 may be located higher than the lower surface 55c of the ceramic substrate 20. However, in order to introduce gas from the lower surface of the plug, it is preferable to provide a gas introduction space that communicates with the gas hole 34 between the lower surface 55c of the ceramic plug 55 and the bonding layer 40. The gas introduction space can be formed, for example, by a recess 55e provided in the lower surface 55c of the ceramic plug 55.

[0036] The ceramic plug 55 may be made of ceramics, such as aluminum oxide, aluminum nitride, quartz, zirconia, or the like. The ceramic plug 55 may also be made of one or more materials selected from aluminum oxide and aluminum nitride, excluding impurities. For example, multiple plugs made of different materials may be stacked vertically. In this case, the upper plug may be made of a ceramic with a higher volume resistivity than the lower plug, and the lower plug may be in contact with a base plate or an electrical conductor, thereby lowering the potential of the lower plug and suppressing discharge in the lower area, where the space is larger and discharge is more likely to occur. Specifically, the upper plug may be made of aluminum oxide and the lower plug may be made of SiC, and they may be arranged in this order in the plug placement hole.

[0037] From the viewpoint of maintaining the fixing strength of the ceramic plug 55, it is preferable that the difference in thermal expansion coefficient between the ceramic plug 55 and the ceramic substrate 20 is small. Therefore, it is preferable that the material constituting the ceramic plug 55 and the material constituting the ceramic substrate 20 both contain one or more selected from aluminum oxide and aluminum nitride, and it is more preferable that the material compositions are the same.

[0038] In this specification, the fixing strength of the ceramic plug 55 is measured according to the following punching test method. FIG. 5 shows a schematic longitudinal cross-sectional view of a compression tester 70 used in the punching test. The compression tester 70 includes a base 71, a cover plate 72, and a punching pin 73 (cylindrical with a tip diameter of 3 mm) that can move up and down at a predetermined speed. The base 71 has a mounting surface 71a for a test piece 74 and a through-hole 71b for dropping the ceramic plug 55 punched out of the test piece 74. The cover plate 72 has an insertion hole 72a for inserting the punching pin 73 in the vertical direction. The base 71 is made of metal. The cover plate 72 is made of metal. The punching pin 73 is made of metal.

[0039] Next, the punching test method will be described. First, a test piece 74 of a ceramic substrate 20 with a ceramic plug 55 embedded in the plug placement hole 50 is placed on the mounting surface 71a of a pedestal 71 with the lower opening 50c of the plug placement hole 50 facing up and the upper opening 50b facing down, and is then clamped and fixed from above with a cover plate 72. The through-hole 71b of the pedestal 71, the plug placement hole 50 of the test piece 74, and the insertion hole 72a of the cover plate 72 are coaxially arranged. Next, a punching pin 73 is moved downward from above the cover plate 72 at a speed of 1 mm / min to punch the ceramic plug 55 from the test piece 74 from the lower opening 50c of the plug placement hole 50 toward the upper opening 50b. The load applied when punching the test piece 74 is continuously measured, and the maximum pressure measured is defined as the punching strength. In this specification, this punching strength is treated as the fixing strength of the ceramic plug 55.

[0040] In one embodiment of the present invention, the punching strength is 1 N / mm 2 The punching strength is preferably 5 N / mm 2 More preferably, 20 N / mm 2 There is no particular upper limit to the punching strength, but from the viewpoint of ensuring strength that makes it easy to pull out the plug without damaging the ceramic plate when replacing the plug, it is preferable to set the upper limit to, for example, 300 N / mm 2 More preferably, it is 100 N / mm 2 More preferably, 50 N / mm 2 Therefore, the punching strength is, for example, 1 to 300 N / mm 2 is preferably 5 to 100 N / mm 2 More preferably, it is 20 to 50 N / mm 2 It is even more preferable that:

[0041] The ceramic plug 55 has a gas flow path 55d penetrating therethrough. In one embodiment, the gas flow path 55d is configured so that gas flowing in from the lower surface 55c of the ceramic plug 55 flows through the gas flow path 55d and exits from the upper surface 55b of the ceramic plug 55. For example, the gas flow path 55d may be formed by forming one or more gas flow paths penetrating vertically through a dense material that does not allow gas flow. In this case, the gas flowing in from the lower surface 55c of the ceramic plug 55 flows through the gas flow path and exits from the upper surface 55b of the ceramic plug 55. The gas flow path may be configured as a straight line, a curve, or a combination of both. However, from the viewpoint of suppressing discharge, a shape in which the flow path length is longer than the vertical length of the ceramic plug 55, such as a bent shape such as a spiral or zigzag shape, is preferred. The term "dense material" used for the ceramic plug 55 means that the porosity of the ceramic plug 55 is 5% or less. The porosity of the ceramic plug 55 is preferably 1% or less, and more preferably 0.5% or less. The porosity of the ceramic plug 55 is measured by the following method. The ceramic plug 55 is cut so that a cross section passing through the central axis extending in the vertical direction of the ceramic plug 55 is exposed. Next, the portion of the cross section excluding the gas flow passage 55d is observed at a magnification of 3000 times using a scanning electron microscope (SEM) at a 2200 μm diameter. 2 The area ratio of the pores observed in the area is determined. Specifically, the SEM image is analyzed, and a threshold is determined using discriminant analysis (Otsu's binarization) from the brightness distribution of the brightness data of the pixels in the image. 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 ceramic plug 55, and the average value of the five locations is taken as the porosity of the ceramic plug 55.

[0042] Examples of methods for manufacturing such a ceramic plug 55 having a gas flow path in a dense material include a method of firing a green body formed using additive manufacturing technology such as a 3D printer, and a method of firing a green body formed by mold casting using a master model produced by a lost-wax casting method. Mold casting is disclosed, for example, in Japanese Patent No. 7,144,603.

[0043] Alternatively, a porous portion may be provided within the ceramic plug 55 to serve as the gas flow path 55d. When the gas flow path 55d is porous, gas flowing in from the lower surface 55c of the ceramic plug 55 flows through the gas flow path 55d, which is formed by a large number of continuous pores, and then flows out from the upper surface 55b of the ceramic plug 55. Because the gas flow path is formed by three-dimensionally connected pores (e.g., a three-dimensional network) within the porous portion, the effective length of the gas flow path 55d is longer than when the gas flow path 55d is hollow, resulting in less electrical discharge. The porous gas flow path can be formed on the inner periphery of the dense outer surface. It is also possible to form one or more additional gas flow paths within the porous gas flow path.

[0044] Therefore, the gas flow passage 55d may be hollow or porous. It is preferable that at least a portion of the gas flow passage 55d is porous. The gas flow passage 55d being hollow means that the porosity of the gas flow passage 55d is 100%. The gas flow passage 55d being porous means that the porosity of the gas flow passage 55d is greater than 5% and less than 100%. A larger porosity of the gas flow passage 55d is preferable to reduce the airflow resistance. Therefore, the porosity of the gas flow passage 55d is preferably 10% or more, more preferably 40% or more. On the other hand, the porosity of the gas flow passage 55d is preferably 50% or less in order to increase the flow passage length of the ceramic plug 55 and ensure the structural strength. Therefore, the porosity of the gas flow passage 55d is preferably, for example, 10% to 50% and more preferably 40% to 50%. The porosity of the gas flow passage 55d is measured, for example, by mercury intrusion porosimetry (JIS R1655:2003).

[0045] The porosity of the ceramic 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 that constitute them. For example, to densify the outer peripheral surface of the ceramic plug, the amount of pore-forming material near the outer peripheral surface may be partially reduced or not used. Also, to densify the inner peripheral surface of the plug placement hole, the amount of pore-forming material near the inner peripheral surface may be partially reduced or not used.

[0046] 2 , the gas supply path 60 for supplying gas to the gas flow path 55d of the ceramic plug 55 through the base plate 30 and the bonding layer 40 includes, for example, a through hole 42 vertically penetrating the bonding layer 40 and a gas hole 34 communicating with the through hole 42 and penetrating the base plate 30 from the upper surface 31 to the lower surface 33. In this embodiment, the base plate 30 may further include a large-diameter portion 34a provided on the upper surface 31 of the base plate 30 at a position facing the through hole 42. By providing the through hole 42 and the large-diameter portion 34a, even if there is a manufacturing error in the plug placement hole 50 and / or the ceramic plug 55 when placing the ceramic plug 55 in the plug placement hole 50, a space is created that allows the ceramic plug 55 to enter, thereby absorbing such manufacturing error. Alternatively, the gas hole 34 may be a straight hole whose diameter is larger than the diameter of the lower opening of the plug placement hole 50.

[0047] An electrical conductor 56 may be disposed in one or both of the through hole 42 and the large diameter portion 34a. Disposing the electrical conductor 56 can further suppress discharge. The electrical conductor 56 may be configured so as not to block the flow of gas through the gas supply path 60, and may not allow gas to pass through the electrical conductor 56. The electrical conductor 56 may also have a structure that allows gas to pass through its interior. In this case, gas in the gas supply path 60 can pass through the electrical conductor 56 and flow to the plug placement hole 50. Examples of materials that allow gas to pass through their interior include a conductive mesh, a conductive fiber mass, a conductive porous body, and a conductive elastic body.

[0048] Examples of materials constituting the electrical conductor 56 include inorganic materials such as metal, carbon, and conductive ceramics. Accordingly, in one embodiment, the electrical conductor 56 contains a metal, carbon, conductive ceramics, or a composite material of two or more of these. Examples include composite materials of metal and ceramics. Examples of metals include single metals selected from Au, Ag, Al, Ti, and Mo, alloys containing one or more of these metals, stainless steels such as SUS316L, highly corrosion-resistant Ni alloys such as Hastelloy, and steel. Examples of carbon include diamond-like carbon (DLC). The surfaces of the inorganic materials may also be coated with diamond-like carbon (DLC). Examples of conductive ceramics include SiC and SiSiC.

[0049] When the electrical conductor 56 is a conductive mesh, the mesh size may be 0.062 mm (250 mesh) to 0.154 mm (100 mesh). When the electrical conductor 56 is a mass of conductive fibers, examples of the material include steel wool, carbon felt, porous metal obtained by sintering Ti fibers or Al powder.

[0050] The electrical conductor 56 is preferably made of a flexible material such as a porous or elastic material. The electrical conductor 56 preferably contacts both the plug 55 and the base plate 30. In this case, it is desirable that at least a portion of the lower surface 55c of the plug 55 is coated with a conductive film, and that this film is in contact with the electrical conductor 56. Examples of materials constituting the conductive film include metal, carbon, and conductive ceramics. Composite materials of metal and ceramic are also included. For example, the porous material may be fibrous or porous, such as titanium or stainless steel, which can enhance the discharge suppression effect while suppressing an increase in airflow resistance. Furthermore, being porous or elastic can facilitate maintaining contact between the plug 55 and the base plate 30. Being porous means that the porosity of the electrical conductor 56 is greater than 5%. A larger porosity of the electrical conductor 56 is preferable to reduce airflow resistance. A porosity of 40% or greater is more preferable. On the other hand, the porosity of the electrical conductor 56 is preferably 50% or less in order to improve the discharge suppression effect. Therefore, the porosity of the electrical conductor 56 is preferably, for example, more than 5% and 50% or less, and more preferably 40% or more and 50% or less. The porosity of the electrical conductor 56 is measured, for example, by the mercury intrusion method (JIS R1655:2003).

[0051] The configuration of the gas supply path 60 is not particularly limited. For example, as shown in FIG. 4 , a semiconductor manufacturing equipment member 10 according to another embodiment of the present invention may be provided with one or more ring portions 64a, each of which extends concentrically with the base plate 30 in a plan view; one or more gas inlet portions 64b for supplying gas introduced from the lower surface 33 of the base plate 30 to the ring portion 64a; and a gas distributor 64c for distributing the gas from the ring portion 64a to each plug 55. In this embodiment, the upper end of the distributor 64c communicates with the through-hole 42 in the bonding layer 40. In FIG. 4 , the same components as those in the embodiment shown in FIG. 1 are denoted by the same reference numerals. The number of gas inlet portions 64b may be fewer than the number of distributor portions 64c, for example, one. This allows the number of gas pipes connected to the base plate 30 to be fewer than the number of plugs 55. Other auxiliary passages (not shown) may also be provided.

[0052] Lift pin holes may also be provided that penetrate the semiconductor manufacturing equipment member 10. The lift pin holes are holes for inserting lift pins that move the wafer W up and down relative to the upper surface 21 of the ceramic substrate 20. When the wafer W is supported by, for example, three lift pins, the lift pin holes are provided in three locations.

[0053] 2. Method of Using the Semiconductor Manufacturing Equipment Component Next, an example of how to use the semiconductor manufacturing equipment component 10 configured as described above will be described. First, with the semiconductor manufacturing equipment component 10 installed in a chamber (not shown), a wafer W is placed on the upper surface 21 of the ceramic substrate 20. The chamber is then depressurized using a vacuum pump to adjust the chamber to a predetermined degree of vacuum, and a voltage is applied to the electrodes 22 of the ceramic substrate 20 to generate an electrostatic adsorption force, thereby adsorbing and fixing the wafer W to the wafer mounting surface (specifically, the upper surfaces of the seal bands 21 a and the small protrusions 21 b).

[0054] Next, a reactive gas atmosphere of a predetermined pressure (e.g., several tens to several hundreds of Pa) is created within the chamber. Under this condition, a high-frequency voltage, such as an RF voltage, is applied between an upper electrode (not shown) installed in the ceiling of the chamber and the base plate 30 of the semiconductor manufacturing equipment member 10 to generate plasma. The surface of the wafer W is processed by the generated plasma. A coolant circulates through the coolant flow path 32 of the base plate 30. A backside gas is introduced into the gas supply path 60 from a gas cylinder (not shown). A thermally conductive gas (e.g., He gas) can be used as the backside gas. The backside gas is supplied to the multiple plug placement holes 50 through the gas supply path 60 and is supplied and sealed in the space between the backside of the wafer W and the reference surface 21c of the wafer mounting surface. The presence of this backside gas efficiently conducts heat between the wafer W and the ceramic substrate 20.

[0055] Furthermore, the provision of the ceramic plug 55 in the plug arrangement hole 50 can suppress discharge within the plug arrangement hole 50. Without the ceramic plug 55, electrons generated as a result of ionization of gas molecules by application of RF voltage accelerate and collide with other gas molecules, causing glow discharge and eventually arc discharge. However, with the ceramic plug 55, the electrons strike the ceramic plug 55 before colliding with other gas molecules, suppressing discharge.

[0056] 3. Manufacturing Method of a Semiconductor Manufacturing Equipment Component Next, a manufacturing method of a semiconductor manufacturing equipment component 10 will be described with reference to FIG. 6 . FIG. 6 is a manufacturing process diagram of a semiconductor manufacturing equipment component 10 according to one embodiment of the present invention. First, a ceramic substrate 20, a base plate 30, and a metal bonding material 90 are prepared ( FIG. 6A ). The ceramic substrate 20 incorporates an electrode 22 and includes a plug placement hole 50. The ceramic substrate 20 can be manufactured by hot-press firing a ceramic compact. The ceramic compact may be manufactured by stacking multiple tape compacts, by mold casting, or by compacting ceramic powder. Next, the plug placement hole 50 is formed in the ceramic substrate 20. The plug placement hole 50 is formed to penetrate the ceramic substrate 20 in the vertical direction, avoiding the electrode 22. The base plate 30 includes a coolant flow path 32 and a gas hole 34. The gas hole 34 has a large diameter portion 34a facing the upper surface 31. The base plate 30 including the coolant flow paths 32 can be manufactured by bonding, for example, a plurality of MMC plate members, in which grooves and holes corresponding to the coolant flow paths 32 have been formed by machining, using a method such as TCB (thermal compression bonding). The gas holes 34 can be formed by machining the base plate 30 after the coolant flow paths 32 have been formed. The metal bonding material 90 has a through hole 92 at a position opposite the large diameter portion 34a of the gas hole 34. The through hole 92 can be formed by machining.

[0057] Next, a metal bonding material 90 is sandwiched between the lower surface 23 of the ceramic substrate 20 and the upper surface 31 of the base plate 30 to form a laminate. The layers are stacked so that the plug placement holes 50 of the ceramic substrate 20, the through holes 92 of the metal bonding material 90, and the gas holes 34 of the base plate 30 are coaxial. The laminate is then pressed and bonded at a temperature below the solidus temperature of the metal bonding material 90 (e.g., a temperature 20°C below the solidus temperature but below the solidus temperature), and then returned to room temperature (TCB). This results in the metal bonding material 90 and the through holes 92 becoming the bonding layer 40 and the through holes 42, respectively, resulting in a bonded body 94 in which the ceramic substrate 20 and the base plate 30 are bonded by the bonding layer 40 ( FIG. 6B ). It is preferable to use a metal bonding material 90 with a thickness of approximately 100 μm (e.g., 80 to 240 μm).

[0058] Next, a ceramic plug 55 having a truncated cone shape and a dense outer peripheral surface 55a and a gas flow path 55d is prepared ( FIG. 6B ). The height of the ceramic plug 55 is the same as the depth of the plug placement hole 50, which is a truncated cone space (i.e., the height of the ceramic substrate 20). The ceramic plug 55 is then press-fit into the plug placement hole 50 from the upper opening 50b toward the lower opening 50c of the ceramic substrate 20. Alternatively, a male thread may be formed on the outer peripheral surface 55a of the ceramic plug 55, which has been previously formed by firing, and a female thread may be formed on the inner peripheral surface 50a of the plug placement hole 50. The ceramic plug 55 may then be threaded into the plug placement hole 50, and the male thread of the ceramic plug 55 may be screwed into the plug placement hole 50 to engage with the female thread of the plug placement hole 50. Alternatively, the ceramic plug 55 may be mounted by injecting a paste-like ceramic mixture, which serves as a precursor of the ceramic plug 55, into the plug placement hole 50 of the ceramic substrate 20 and firing the mixture. Thereafter, the semiconductor manufacturing equipment member 10 is completed by appropriately going through processes such as adjusting the overall shape (FIG. 6C).

[0059] 1. Preparation of Test Specimens (1-1. Preparation of Ceramic Substrates) An alumina disk measuring 30 mm in diameter and 5 mm in thickness was prepared. A truncated conical plug placement hole having a tapered inner peripheral surface with an inclination angle relative to the lower opening shown in Table 1 was formed in the center of this disk according to the test number, to obtain a ceramic substrate for testing. The porosity of the inner peripheral surface of the plug placement hole was measured according to JIS R1634:1998, as described above, for ceramic substrates separately prepared by the same manufacturing method according to the test number.

[0060] (1-2. Fabrication of Ceramic Plugs) A 5 mm-tall truncated cone-shaped alumina ceramic plug with a dense outer circumferential surface was fabricated. This ceramic plug was fabricated using the following procedure. First, a mold (master) was fabricated using a 3D printer to form the upper and lower surfaces of the plug, the outer circumferential surface, and the hollow gas flow path. The mold was made of a material insoluble in ceramics. Preferably, the mold was made of a material (e.g., paraffin wax) that was soluble in a predetermined cleaning solution (e.g., isopropyl alcohol) after hardening. The portion that would ultimately become the plug was hollow. A ceramic slurry was poured into this master and fired. The plug was then allowed to cool to room temperature, and the plug was released from the master to obtain an alumina ceramic plug. The inclination angle of the outer circumferential surface of the fabricated ceramic plug was the same as the inclination angle of the inner circumferential surface of the plug placement hole with the corresponding test number. Furthermore, the horizontal cross-sectional diameter of each plug at any height position was 5 μm larger than the horizontal cross-sectional diameter of the plug placement hole at the same height position. The porosity of the outer peripheral surface of the ceramic plug was measured by SEM observation as described above for ceramic plugs separately prepared by the same manufacturing method according to the test number. The porosity of the ceramic plug (as a whole) was measured by SEM observation as described above for ceramic plugs separately prepared by the same manufacturing method according to the test number.

[0061] (1-3. Press-fitting of ceramic plugs) Next, the ceramic plugs were press-fitted into the plug placement holes from the upper opening toward the lower opening of the ceramic substrate until the upper surface of the ceramic plug was flush with the upper surface of the ceramic substrate. The pressure during press-fitting was 10 MPa. At this time, for all test numbers, the height positions of the upper and lower surfaces of the ceramic plugs embedded in the plug placement holes easily matched the height positions of the upper and lower surfaces of the ceramic substrate, respectively.

[0062] 2. Measurement of Punching Strength The punching strength of the ceramic plugs prepared by the above procedure was measured according to the punching test method described above. An Instron universal testing machine, Model 5566, was used as the compression tester. The compression tester had the configuration shown in Figure 5, and the test pieces were set in the compression tester to measure the punching strength. The results are shown in Table 1.

[0063]

[0064] 3. Discussion The test results show that it is possible to embed a plug into a plug positioning hole with high positioning accuracy without using adhesive in both Examples 1 and 2. It also shows that by setting the inclination angle of the inner peripheral surface of the plug positioning hole to an appropriate value and using a plug with an outer peripheral surface that can fit into the plug positioning hole, it is possible to prevent the plug from being too easily pulled out upward.

[0065] 10: Semiconductor manufacturing equipment member 20: Ceramic substrate 21: Upper surface 21a: Seal band 21b: Small protrusion 21c: Reference surface 22: Electrode 23: Lower surface 30: Base plate 31: Upper surface 32: Coolant flow path 33: Lower surface 34: Gas hole 34a: Large diameter portion 40: Bonding layer 42: Through hole 50: Plug placement hole 50a: Inner peripheral surface 50b: Upper opening 50c: Lower opening 55: Plug 55a: Outer peripheral surface 55b: Upper surface 55c: Lower surface 55d: Gas flow path 55e: Recess 56: Electrical conductor 60: Gas supply path 64a: Ring portion 64b: Gas introduction portion 64c: Distribution portion 70 : Compression tester 71 : Base 71a : Mounting surface 71b : Through-hole 72 : Cover plate 72a : Insertion hole 73 : Punching pin 74 : Test piece 90 : Metal bonding material 92 : Through-hole 94 : Bonded body

Claims

1. A member for a semiconductor manufacturing apparatus, comprising: a ceramic substrate having an upper surface and a lower surface for placing a wafer; a plug placement hole penetrating the ceramic substrate in the vertical direction and having a tapered inner peripheral surface with an upper opening area larger than a lower opening area; a ceramic plug having a dense outer peripheral surface and a gas flow path penetrating the plug, the dense outer peripheral surface of the plug being embedded so as to directly fit onto the inner peripheral surface of the plug placement hole; a conductive base plate joined to the lower surface of the ceramic substrate via a joining layer; and a gas supply path for supplying gas to the gas flow path of the ceramic plug through the base plate and the joining layer.

2. The member for a semiconductor manufacturing apparatus according to claim 1, wherein an inclination angle of the inner peripheral surface of the plug placement hole with respect to the lower opening is 70° or more and 87° or less.

3. The member for a semiconductor manufacturing apparatus according to claim 1 or 2, wherein the inner peripheral surface of the plug placement hole that fits with the dense outer peripheral surface of the ceramic plug is dense.

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

5. The member for a semiconductor manufacturing apparatus according to claim 1 or 2, wherein a porosity of the dense outer peripheral surface of the ceramic plug is 1% or less.

6. The member for a semiconductor manufacturing apparatus according to claim 1 or 2, wherein the ceramic plug has a frustum of a cone shape.

7. The member for a semiconductor manufacturing apparatus according to claim 1 or 2, wherein a thickness from the upper opening to the lower opening of the ceramic substrate is 1 mm or more.

8. The punching strength when punching out the ceramic plug from the plug placement hole from the lower opening to the upper opening of the plug placement hole according to the punching test method described in this specification is 1 N / mm 2 or more, for the member for a semiconductor manufacturing apparatus according to claim 1 or 2.

Images