Member for semiconductor manufacturing device

Abstract

A member 10 for a semiconductor manufacturing device comprises: a central ceramic member 22 having a wafer mounting surface 22a as an upper surface thereof; an annular outer peripheral ceramic member 32 having an FR mounting surface 32a as an upper surface thereof and disposed at an outer peripheral side of the central ceramic member 22; and a conductive base member 40 having a central support part that supports the central ceramic member 22 and an outer peripheral support part that supports the outer peripheral ceramic member 32. Both the outer peripheral surface 25 of the central ceramic member 22 and the inner peripheral surface 35 of the outer peripheral ceramic member 32 have a diameter that varies in the up-down direction. The maximum diameter of the outer peripheral surface 25 of the central ceramic member 22 is smaller than the maximum diameter of the inner peripheral surface 35 of the outer peripheral ceramic member 32, and is larger than the minimum diameter of the inner peripheral surface 35 of the outer peripheral ceramic member 32.

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 utilize plasma to perform CVD or etching on wafers. In these semiconductor manufacturing equipment components, a focus ring may be used around the wafer to ensure uniformity of the plasma around the wafer's periphery. For example, a holding device disclosed in Patent Document 1 includes a central electrostatic chuck portion that primarily holds the wafer and a peripheral electrostatic chuck portion that primarily holds the focus ring. The central electrostatic chuck portion includes a central ceramic member to which the wafer is attracted and a metal central base member joined to the lower surface of the central ceramic member by a resin central joint. The peripheral electrostatic chuck portion includes a peripheral ceramic member to which the focus ring is attracted and a metal central base member joined to the lower surface of the peripheral ceramic member by a resin peripheral joint. The peripheral electrostatic chuck portion is a substantially annular member that surrounds the central electrostatic chuck portion in a plan view. The peripheral electrostatic chuck portion is a separate member from the central electrostatic chuck portion, and a gap exists between the peripheral electrostatic chuck portion and the central electrostatic chuck portion.

[0003] Patent No. 7152926

[0004] In a semiconductor manufacturing equipment component having a gap between a central electrostatic chuck portion and a peripheral electrostatic chuck portion, such as the holding device of Patent Document 1, the metal base member or resin joint exposed in the gap may corrode, shortening the device's lifespan. According to the findings of the present inventors, such shortened lifespan is caused by ions of argon or the like used in plasma processing being accelerated toward the semiconductor manufacturing equipment component, penetrating the gap, colliding with other atoms or molecules in the gap to generate plasma or radicals, which corrode the surrounding metal or resin.

[0005] The present invention has been made to solve such problems, and a main object of the present invention is to suppress a decrease in the life of the device.

[0006] [1] A semiconductor manufacturing equipment member of the present invention comprises: a central ceramic member having a wafer mounting surface on its upper surface; an annular peripheral ceramic member having a focus ring mounting surface on its upper surface and disposed on the outer periphery of the central ceramic member; a conductive base member having a central support portion bonded to the underside of the central ceramic member and supporting the central ceramic member, and an outer support portion bonded to the underside of the outer ceramic member and supporting the outer periphery ceramic member, the central support portion and the outer support portion being separate or integral with each other; wherein the outer periphery of the central ceramic member and the inner periphery of the outer ceramic member both have diameters that vary in the vertical direction, and the maximum diameter of the outer periphery of the central ceramic member is smaller than the maximum diameter of the inner periphery of the outer ceramic member and is larger than the minimum diameter of the inner periphery of the outer ceramic member.

[0007] In this semiconductor manufacturing equipment component, the diameters of the outer peripheral surface of the central ceramic member and the inner peripheral surface of the outer peripheral member both vary in the vertical direction. The maximum diameter of the outer peripheral surface of the central ceramic member is smaller than the maximum diameter of the inner peripheral surface of the outer peripheral member and smaller than the minimum diameter of the inner peripheral surface of the outer peripheral member. Therefore, when the semiconductor manufacturing equipment component is viewed from above, the outer peripheral portion of the central ceramic member overlaps the inner peripheral portion of the outer peripheral member. In this semiconductor manufacturing equipment component, ions accelerated toward the semiconductor manufacturing equipment component during plasma processing collide with the ceramic member before reaching the base member or the joint and do not continue beyond that. This suppresses the generation of plasma and radicals around the base member and the joint, thereby reducing the reduction in the equipment life.

[0008] Although the present invention is sometimes described using terms such as up / down, left / right, front / back, etc., these terms merely refer to relative positional relationships. Therefore, when the orientation of a semiconductor manufacturing equipment component is changed, up / down may become left / right, or left / right may become up / down, and such cases are also within the technical scope of the present invention.

[0009] [2] In the semiconductor manufacturing equipment component of the present invention (the semiconductor manufacturing equipment component described in [1]), the minimum diameter of the outer peripheral surface of the central ceramic member may be smaller than the minimum diameter of the inner peripheral surface of the outer peripheral ceramic member. Such central ceramic member and outer peripheral ceramic member can be produced, for example, by hollowing out a single ceramic plate.

[0010] [3] In the semiconductor manufacturing equipment member of the present invention (the semiconductor manufacturing equipment member according to [1] or [2]), the outer peripheral surface of the central ceramic member and the inner peripheral surface of the peripheral ceramic member may each appear as a diagonal line in a cross section of the semiconductor manufacturing equipment member cut in a direction perpendicular to the wafer-mounting surface. Such a central ceramic member and a peripheral ceramic member can be produced, for example, by hollowing out a ceramic plate into a truncated cone shape or an inverted truncated cone shape.

[0011] [4] In the semiconductor manufacturing equipment member of the present invention (the semiconductor manufacturing equipment member according to any one of [1] to [3]), the outer peripheral surface of the central ceramic member may be a tapered surface whose diameter increases toward the top.

[0012] [5] In the semiconductor manufacturing equipment member of the present invention (the semiconductor manufacturing equipment member according to any one of [1] to [3]), the outer peripheral surface of the central ceramic member may be a tapered surface whose diameter decreases toward the top.

[0013] [6] In the semiconductor manufacturing equipment member of the present invention (the semiconductor manufacturing equipment member according to any one of [1] to [5]), the outer periphery support portion may be an annular portion disposed on the outer periphery of the central support portion with a gap therebetween. This facilitates separate control of the temperatures of the outer periphery support portion and the central support portion, thereby facilitating separate control of the temperatures of the wafer mounting surface and the focus ring mounting surface.

[0014] [7] In the semiconductor manufacturing equipment component of the present invention (the semiconductor manufacturing equipment component described in [6]), the central ceramic member and the central support member may be joined by a metallic central joint member, the outer peripheral surface of which, together with the outer peripheral surface of the central support member, is covered with a central insulating film, and the outer ceramic member and the outer peripheral support member may be joined by a metallic outer peripheral joint member, the inner peripheral surface of which, together with the inner peripheral surface of the outer peripheral support member, is covered with an outer peripheral insulating film. In this way, since the joint member and the base member are covered with an insulating film, corrosion of the joint member and the base member is further suppressed. Furthermore, since the joint member is made of metal rather than resin, the joint member is less likely to deteriorate even if an insulating film is formed by thermal spraying or the like.

[0015] [8] In the semiconductor manufacturing equipment member of the present invention (the semiconductor manufacturing equipment member according to any one of [1] to [6]), the central ceramic member and the central support part may be joined by a central joint part made of resin, and the peripheral ceramic member and the peripheral support part may be joined by a peripheral joint part made of resin. Since resin adhesive layers are susceptible to corrosion, the application of the present invention is highly significant.

[0016] [9] Alternatively, a semiconductor manufacturing equipment member of the present invention may comprise: an annular peripheral ceramic member having a focus ring mounting surface on an upper surface thereof and configured to be positionable on the outer circumferential side of a central ceramic member having a wafer mounting surface; and a conductive base member bonded to a lower surface of the peripheral ceramic member and having an outer circumferential support portion for supporting the peripheral ceramic member, wherein the inner circumferential surface of the peripheral ceramic member has a diameter that varies in the vertical direction, and the inner circumferential surface of the peripheral ceramic member is a tapered surface whose diameter increases or decreases toward the upper side, for mounting a focus ring.

[0017] 5 is a longitudinal cross-sectional view of a semiconductor manufacturing equipment member 10. FIG. 6 is a plan view of the semiconductor manufacturing equipment member 10. FIG. 7 is a partial enlarged view of FIG. 1. FIG. 8 is a manufacturing process diagram of a central ceramic member 22 and a peripheral ceramic member 32. FIG. 9 is a longitudinal cross-sectional view of a semiconductor manufacturing equipment member 10B of another example. FIG. 11 is a plan view of a semiconductor manufacturing equipment member 10B of another example. FIG. 12 is a partial enlarged view of FIG. 13. FIG. 14 is a longitudinal cross-sectional view of a semiconductor manufacturing equipment member 10C of another example. FIG. 15 is a longitudinal cross-sectional view of a semiconductor manufacturing equipment member 10D of another example. FIG. 16 is a partial enlarged view of a semiconductor manufacturing equipment member 110 of a comparative embodiment.

[0018] Preferred embodiments of the present invention will be described below with reference to the drawings. Fig. 1 is a longitudinal cross-sectional view of a semiconductor manufacturing equipment member 10 (a cross-sectional view taken along a plane including the central axis of the semiconductor manufacturing equipment member 10). Fig. 2 is a plan view of the semiconductor manufacturing equipment member 10. Fig. 3 is a partially enlarged view of Fig. 1. Fig. 4 is a manufacturing process diagram for a central ceramic member 22 and a peripheral ceramic member 32.

[0019] The semiconductor manufacturing equipment component 10 is used to perform plasma-assisted CVD, etching, and other processes on wafers W and is fixed to a mounting plate 84 installed inside a semiconductor process chamber 80. The semiconductor manufacturing equipment component 10 includes a central ceramic member 22, a peripheral ceramic member 32, and a base member 40. In this embodiment, the base member 40 includes a central base member 42 serving as a central support member and a peripheral base member 52 serving as a peripheral support member. The central ceramic member 22 and the central base member 42 are joined at a central joint 62. The peripheral ceramic member 32 and the peripheral base member 52 are joined at a peripheral joint 67. The central ceramic member 22 and the peripheral ceramic member 32 are collectively referred to as ceramic member 20. The central joint 62 and the peripheral joint 67 are collectively referred to as joint 60. The semiconductor manufacturing equipment component 10 may include a focus ring 70. Hereinafter, "focus ring" will be abbreviated as "FR."

[0020] The central ceramic member 22 is a ceramic disk member having a circular wafer support surface 22a on its upper surface. A wafer W is placed on the wafer support surface 22a. The diameter of the wafer support surface 22a is smaller than the diameter of the wafer W (e.g., 300 mm). The central ceramic member 22 is formed of a ceramic material such as alumina or aluminum nitride. The central ceramic member 22 incorporates a wafer attraction electrode 24. The wafer attraction electrode 24 is formed of a material containing, for example, W, Mo, WC, or MoC. The wafer attraction electrode 24 is a plate-like or mesh-like monopolar electrostatic electrode. The layer of the central ceramic member 22 above the wafer attraction electrode 24 functions as a dielectric layer. A DC wafer attraction power supply (not shown) is connected to the wafer attraction electrode 24.

[0021] The peripheral ceramic member 32 is an annular member having an annular FR mounting surface 32a on its upper surface. The peripheral ceramic member 32 is separate from the central ceramic member 22 and is disposed on the outer periphery of the central ceramic member 22 with a gap therebetween. The FR mounting surface 32a is located one step lower than the wafer mounting surface 22a. An FR 70 is mounted on the FR mounting surface 32a. The inner diameter of the FR mounting surface 32a is approximately the same as the inner diameter of the FR 70. The peripheral ceramic member 32 is formed of a ceramic material such as alumina or aluminum nitride. The peripheral ceramic member 32 incorporates an FR chucking electrode 34. The FR chucking electrode 34 is formed of a material containing, for example, W, Mo, WC, or MoC. The FR chucking electrode 34 is a plate-shaped or mesh-shaped monopolar electrostatic electrode. The layer of the peripheral ceramic member 32 above the FR attracting electrode 34 functions as a dielectric layer. An FR attracting DC power supply (not shown) is connected to the FR attracting electrode 34. The peripheral ceramic member 32 may have the same thickness as the central ceramic member 22.

[0022] The outer peripheral surface 25 of the central ceramic member 22 is a tapered surface (the outer surface of an inverted truncated cone) whose diameter increases toward the top. As shown in FIG. 3 , the outer peripheral surface 25 of the central ceramic member 22 is inclined outward at an angle α relative to the vertical direction, starting from its lower end 25b. The angle α is, for example, 10° to 80°. The inner peripheral surface 35 of the outer peripheral ceramic member 32 is a tapered surface (the inner surface of an inverted truncated cone carved out of a disk) whose diameter increases toward the top. As shown in FIG. 3 , the inner peripheral surface 35 of the outer peripheral ceramic member 32 is inclined outward at an angle β relative to the vertical direction, starting from its lower end 35b. The angle β is, for example, 10° to 80°. The angle β may be the same as or different from the angle α. 2 , the maximum diameter Pmax of the outer peripheral surface 25 of the central ceramic member 22 (in this embodiment, the diameter of the upper end 25 a of the outer peripheral surface 25) is smaller than the maximum diameter Qmax of the inner peripheral surface 35 of the outer peripheral ceramic member 32 (in this embodiment, the diameter of the upper end 35 a of the inner peripheral surface 35) and is larger than the minimum diameter Qmin of the inner peripheral surface 35 of the outer peripheral ceramic member 32 (in this embodiment, the diameter of the lower end 35 b of the inner peripheral surface 35). Therefore, when the semiconductor manufacturing equipment member 10 is viewed from above, the outer peripheral portion 26 of the central ceramic member 22 and the inner peripheral portion 36 of the outer peripheral ceramic member 32 overlap. Note that when the semiconductor manufacturing equipment member 10 is viewed from above, the inner peripheral surface 35 of the outer peripheral ceramic member 32 is located between the wafer mounting surface 22 a and the FR mounting surface 32 a, and it is not possible to see through to it.

[0023] The central ceramic member 22 and the peripheral ceramic member 32 may be manufactured, for example, as follows. FIG. 4 is a manufacturing process diagram for the central ceramic member 22 and the peripheral ceramic member 32. First, as shown in FIG. 4A , a ceramic plate 21 is prepared in which a wafer adsorption electrode 24 and an FR adsorption electrode 34 are embedded. This ceramic plate 21 is manufactured, for example, as follows. First, two circular ceramic powder molded bodies are produced. Next, a central printed electrode having the same shape as the wafer adsorption electrode 24 and a peripheral printed electrode having the same shape as the FR adsorption electrode 34 are printed on the upper surface of the first circular ceramic plate so that they are concentric with the circular ceramic plate. Then, a second circular ceramic plate is stacked on the printed electrode surface of the first circular ceramic plate to form a laminate. This laminate is then hot-pressed and fired to obtain the ceramic plate 21. Next, as shown in FIG. 4B , the circular center of the ceramic plate 21 is machined to separate it into an annular peripheral portion, thereby obtaining the central ceramic member 22 and the peripheral ceramic member 32. When hollowing out the center of the disk, the disk is machined so that the center has an inverted truncated cone shape. Producing the central ceramic member 22 and the peripheral ceramic member 32 from a single ceramic plate in this manner reduces manufacturing costs compared to preparing separate ceramic plates for the central ceramic member 22 and the peripheral ceramic member 32. Furthermore, the size of the gap between the central ceramic member 22 and the peripheral ceramic member 32 thus produced can be adjusted simply by shifting their relative vertical positions, as shown in FIG. 4C . The outer peripheral surface 25 of the central ceramic member 22 and the inner peripheral surface 35 of the peripheral ceramic member 32 may be further machined to form irregularities.

[0024] The central base member 42 is a conductive disk member having a circular central support surface 42a on its upper surface. The central ceramic member 22 is bonded to the central support surface 42a. The diameter of the central support surface 42a is the same as the diameter of the lower surface of the central ceramic member 22. The central base member 42 has a central refrigerant channel 44 therein through which a refrigerant can circulate. This central refrigerant channel 44 is arranged in a single stroke across the entire central base member 42 in a plan view. The refrigerant flowing through the central refrigerant channel 44 is preferably a liquid, and is preferably electrically insulating. Examples of electrically insulating liquids include fluorine-based inert liquids. The central base member 42 is made of a conductive material containing, for example, a metal. Examples of conductive materials include metals and composite materials. Examples of metals include Al, Ti, Mo, and alloys thereof. Examples of composite materials include metal matrix composites (MMCs) and ceramic matrix composites (CMCs). Specific examples of such composite materials include materials containing Si, SiC, and Ti, and materials in which porous SiC is impregnated with Al and / or Si. Materials containing Si, SiC, and Ti are referred to as SiSiCTi, materials in which porous SiC is impregnated with Al are referred to as AlSiC, and materials in which porous SiC is impregnated with Si are referred to as SiSiC. To improve cooling efficiency, it is preferable to select a material with high thermal conductivity for the central base member 42, such as Al or an Al alloy. Furthermore, to prevent damage due to thermal stress, it is preferable to select a material for the central base member 42 with a thermal expansion coefficient close to that of the material of the central ceramic member 22, such as a metal-ceramic composite. The central base member 42 also serves as an RF electrode. A central insulating film 77 made of an insulating material (e.g., alumina or yttria) is formed on the outer circumferential surface of the central base member 42. The central insulating film 77 may be a thermally sprayed film.

[0025] The peripheral base member 52 is a conductive annular member having an annular peripheral support surface 52a on its upper surface. The peripheral base member 52 is separate from the central base member 42 and is disposed on the outer periphery of the central base member 42 with a gap therebetween. The peripheral support surface 52a is located one step lower than the central support surface 42a. The peripheral ceramic member 32 is bonded to the peripheral support surface 52a. The inner and outer diameters of the peripheral support surface 52a are the same as the inner and outer diameters of the lower surface of the peripheral ceramic member 32, respectively. The peripheral base member 52 has a peripheral refrigerant flow path 54 therein through which a refrigerant can circulate. This peripheral refrigerant flow path 54 is formed in a single stroke across the entire peripheral base member 52 in a plan view. The refrigerant flowing through the peripheral refrigerant flow path 54 is preferably a liquid, preferably electrically insulating. Examples of electrically insulating liquids include fluorine-based inert liquids. The peripheral base member 52 is made of a conductive material containing metal. Examples of conductive materials include the materials exemplified for the central base member 42. To enhance cooling efficiency, it is preferable to select a material with high thermal conductivity for the peripheral base member 52, such as aluminum or an aluminum alloy. To prevent damage due to thermal stress, it is preferable to select a material with a thermal expansion coefficient similar to that of the material for the peripheral ceramic member 32, such as a metal-ceramic composite. The peripheral base member 52 also serves as an RF electrode. A peripheral insulating film 78 made of an insulating material (e.g., alumina or yttria) is formed on the inner circumferential surface of the peripheral base member 52. Furthermore, a peripheral outermost insulating film 79 made of an insulating material (e.g., alumina or yttria) is formed on the outer circumferential surface of the peripheral base member 52. The peripheral insulating film 78 and the peripheral outermost insulating film 79 may be thermally sprayed.

[0026] The central bonding portion 62 bonds the lower surface of the central ceramic member 22 to the upper surface of the central base member 42. In this embodiment, the central bonding portion 62 is an adhesive layer made of resin. Examples of the resin that can be used include acrylic resin, silicone resin, and epoxy resin. The adhesive layer may further contain a filler.

[0027] The outer peripheral bonding portion 67 bonds the lower surface of the outer peripheral ceramic member 32 to the upper surface of the outer peripheral base member 52. In this embodiment, the outer peripheral bonding portion 67 is an adhesive layer made of resin. Examples of the resin that can be used include acrylic resin, silicone resin, and epoxy resin. The adhesive layer may further contain a filler.

[0028] The FR 70 is an annular member placed on the FR mounting surface 32a and is made of, for example, silicon. A step 72 is provided along the circumferential direction at the upper part of the inner peripheral surface of the FR 70. The step 72 is provided to prevent the wafer W from interfering with the FR 70. The inner diameter of the FR 70 is approximately the same as the inner diameter of the FR mounting surface 32a.

[0029] Next, an example of how the semiconductor manufacturing equipment component 10 is used will be described with reference to FIG. 1 . The chamber 80 has a shower head 82 on its ceiling. The semiconductor manufacturing equipment component 10 is fixed to a mounting plate 84 disposed inside the chamber 80. Specifically, the semiconductor manufacturing equipment component 10 is fixed to the mounting plate 84 by concentrically arranging O-rings 87, 88, and 89 between the lower surface of the base member 40 and the upper surface of the mounting plate 84, and then fastening the mounting plate 84 and the base member 40 with multiple bolts 90. The O-ring 87 has a diameter approximately the same as that of the central base member 42, the O-ring 88 has a diameter approximately the same as the inner diameter of the outer base member 52, and the O-ring 89 has a diameter approximately the same as the outer diameter of the outer base member 52. The bolts 90 have a head and a foot. The bolts 90 are inserted from below into stepped bolt insertion holes 86 that penetrate the installation plate 84 in the vertical direction, and the feet are screwed into the screw holes 41 provided in the underside of the base member 40. At this time, the heads of the bolts 90 engage with the stepped portions of the bolt insertion holes 86. The O-rings 87, 88, and 89 are compressed in the vertical direction to provide a seal. If there are other locations that require sealing, additional O-rings are also provided in those locations.

[0030] When a wafer W is processed using the semiconductor manufacturing equipment member 10, an FR 70 is placed on the FR mounting surface 32a of the semiconductor manufacturing equipment member 10, and a disk-shaped wafer W is placed on the wafer mounting surface 22a. In this state, a DC voltage is applied to the wafer suction electrode 24 to attract the wafer W to the wafer mounting surface 22a, and a DC voltage is applied to the FR suction electrode 34 to attract the FR 70 to the FR mounting surface 32a. The interior of the chamber 80 is then set to a predetermined vacuum atmosphere (or reduced-pressure atmosphere), and a high-frequency voltage is applied between the shower head 82 and the base member 40 while a process gas is supplied from the shower head 82. This generates plasma between the base member 40 and the shower head 82. The wafer W is then processed using this plasma.

[0031] The FR 70 is also consumed as the wafers W are plasma processed. However, since the FR 70 is thicker than the wafers W, the FR 70 is replaced after processing a plurality of wafers W.

[0032] Dry cleaning of the semiconductor manufacturing equipment component 10 itself may be performed without a wafer W placed on the wafer mounting surface 22a of the semiconductor manufacturing equipment component 10 (waferless dry cleaning). Waferless dry cleaning can be performed with an FR 70 placed on the FR ring mounting surface 32a or without an FR 70 placed on the FR mounting surface 32a. When performing dry cleaning with an FR placed on it, a DC voltage is applied to the FR adsorption electrode 34 to adsorb the FR 70 to the FR mounting surface 32a. The interior of the chamber 80 is then set to a predetermined vacuum atmosphere (or reduced-pressure atmosphere), and a high-frequency voltage is applied between the shower head 82 and the base member 40 while a cleaning gas is supplied from the shower head 82. Plasma is then generated between the base member 40 and the shower head 82. This plasma is then used to clean the semiconductor manufacturing equipment component 10, etc.

[0033] When the semiconductor manufacturing equipment member 10 is in use, plasma ions (e.g., argon ions) generated between the base member 40 and the showerhead 82 are accelerated toward the semiconductor manufacturing equipment member 10 in a direction substantially perpendicular to the wafer mounting surface 22a and the FR mounting surface 32a. The accelerated ions collide with other molecules or atoms (e.g., atoms or molecules of a corrosive gas) to generate plasma or radicals, which may corrode surrounding metals or resins. Such corrosion is particularly a concern during waferless dry cleaning.

[0034] This point will be explained in detail below. FIG. 10 is a partially enlarged view of a semiconductor manufacturing equipment component 110 according to a comparative example (the prior art disclosed in Patent Document 1). In the semiconductor manufacturing equipment component 110, the outer peripheral surface 125 of the central ceramic member 122 and the inner peripheral surface 135 of the outer peripheral ceramic member 132 both have a constant diameter in the vertical direction. When the semiconductor manufacturing equipment component 110 is viewed from above, the central ceramic member 122 and the outer peripheral ceramic member 132 do not overlap, and the gap between them is visible to the depth. In this semiconductor manufacturing equipment component 110, accelerated ions penetrate the gap between the central base member 142 and the outer peripheral base member 152 and between the central joint portion 162 and the outer peripheral joint portion 167, as shown in FIG. 10A . The accelerated ions then collide with other atoms or molecules in the gap, generating plasma or radicals, which corrode the surrounding base member 140 and joint portion 160 and shortens the service life of the semiconductor manufacturing equipment component 110. In the semiconductor manufacturing equipment component 110, the outer peripheral surface 125 of the central ceramic member 122 has a step 125s that narrows in diameter at the top along the circumferential direction. As shown in FIG. 10B , the inner peripheral portion of the FR 170 is positioned on this step 125s. As a result, when waferless dry cleaning is performed with the FR 170 placed on the FR mounting surface 132a, accelerated ions collide with the FR 170 and do not travel beyond it, thereby suppressing corrosion of the base member 140 and the joint 160. However, because waferless dry cleaning is performed with the FR 170 placed on the FR mounting surface 132a, the accelerated ions corrode the FR 170, shortening its lifespan. Therefore, using the semiconductor manufacturing equipment component 110 increases the running costs of the entire semiconductor manufacturing equipment and shortens its lifespan.

[0035] In contrast, in this embodiment, the diameters of the outer peripheral surface 25 of the central ceramic member 22 and the inner peripheral surface 35 of the outer peripheral ceramic member 32 both change in the vertical direction, and when the semiconductor manufacturing equipment component 10 is viewed from above, the outer peripheral portion 26 of the central ceramic member 22 and the inner peripheral portion 36 of the outer peripheral ceramic member 32 overlap. In this semiconductor manufacturing equipment component 10, as shown in FIG. 3 , accelerated ions collide with the ceramic member 20 before reaching the base member 40 or the joint 60 and do not proceed beyond that. This suppresses the generation of plasma and radicals around the base member 40 and the joint 60, thereby suppressing corrosion of the base member 40 and the joint 60, and as a result, suppresses a decrease in the device life. Furthermore, in a plan view of the semiconductor manufacturing equipment component 10, the outer peripheral portion 26 of the central ceramic member 22 and the inner peripheral portion 36 of the outer peripheral ceramic member 32 overlap, so even if waferless dry cleaning is performed without placing the FR 70 on the FR mounting surface 32a, corrosion of the base member 40 and the joints 60 can be suppressed. This makes it possible to improve the life of the FR 70 and suppress a decrease in the life of the entire semiconductor manufacturing equipment.

[0036] In the semiconductor manufacturing equipment component 10 described above, the diameters of the outer peripheral surface 25 of the central ceramic member 22 and the inner peripheral surface 35 of the outer peripheral ceramic member 32 both vary in the vertical direction. The maximum diameter Pmax of the outer peripheral surface 25 of the central ceramic member 22 is smaller than the maximum diameter Qmax of the inner peripheral surface 35 of the outer peripheral ceramic member 32, and is smaller than the minimum diameter Qmin of the inner peripheral surface 35 of the outer peripheral ceramic member 32. Therefore, when the semiconductor manufacturing equipment component 10 is viewed from above, the outer peripheral portion 26 of the central ceramic member 22 and the inner peripheral portion 36 of the outer peripheral ceramic member 32 overlap. Therefore, as described above, a decrease in the equipment life is suppressed.

[0037] Furthermore, the minimum diameter Pmin of the outer peripheral surface 25 of the central ceramic member 22 (in this embodiment, the diameter of the lower end 25b of the outer peripheral surface 25) is smaller than the minimum diameter Qmin of the inner peripheral surface 35 of the outer peripheral ceramic member 32. The central ceramic member 22 and the outer peripheral ceramic member 32 can be produced, for example, by hollowing out a single ceramic plate. In this case, manufacturing costs can be reduced more easily than if a ceramic plate for the central ceramic member 22 and a ceramic plate for the outer peripheral ceramic member 32 were separately prepared.

[0038] Furthermore, in a cross section of the semiconductor manufacturing equipment member 10 cut in a direction perpendicular to the wafer mounting surface 22a, the outer peripheral surface 25 of the central ceramic member 22 and the inner peripheral surface 35 of the outer peripheral ceramic member 32 each appear as a diagonal line. The central ceramic member 22 and the outer peripheral ceramic member 32 can be fabricated, for example, by hollowing out a single ceramic plate into a truncated cone shape or an inverted truncated cone shape. Such shapes are relatively easy to hollow out and tend to keep manufacturing costs down.

[0039] Furthermore, the peripheral base member 52 serving as the peripheral support portion is an annular member disposed with a gap between it and the central base member 42 serving as the central support portion, which makes it easy to individually control the temperatures of the peripheral base member 52 and the central base member 42, and therefore easy to individually control the temperatures of the wafer mounting surface 22a and the FR mounting surface 32a.

[0040] The central ceramic member 22 and the central base member 42 serving as the central support are joined by a resin central joint 62, and the peripheral ceramic member 32 and the peripheral base member 52 serving as the peripheral support are joined by a resin peripheral joint 67. Because resin adhesive layers are susceptible to corrosion, the application of the present invention is highly significant.

[0041] It goes without saying that the present invention is not limited to the above-described embodiment, and can be embodied in various forms as long as they fall within the technical scope of the present invention.

[0042] In the above-described embodiment, the outer peripheral surface 25 of the central ceramic member 22 is a tapered surface with a diameter increasing toward the top. However, this is not limited to this, as long as the diameter changes vertically. The outer peripheral surface 25 of the central ceramic member 22 may be a tapered surface (the outer surface of a truncated cone) with a diameter decreasing toward the top, as in the semiconductor manufacturing equipment member 10B shown in Figures 5 to 7 . Furthermore, in the above-described embodiment, the inner peripheral surface 35 of the outer peripheral ceramic member 32 is a tapered surface with a diameter increasing toward the top. However, this is not limited to this, as long as the diameter changes vertically. The inner peripheral surface 35 of the outer peripheral ceramic member 32 may be a tapered surface with a diameter decreasing toward the top (the inner surface of a truncated cone carved out of a disk), as in the semiconductor manufacturing equipment member 10B. Note that in Figures 5 to 7 , the same components as those in the above-described embodiment are designated by the same reference numerals.

[0043] In the semiconductor manufacturing equipment member 10B, the outer peripheral surface 25 of the central ceramic member 22 is inclined inwardly by an angle γ with respect to the vertical direction starting from its lower end 25b, as shown in FIG. 7 . The angle γ is, for example, 10° to 80°. The inner peripheral surface 35 of the outer peripheral ceramic member 32 is inclined inwardly by an angle δ with respect to the vertical direction starting from its lower end 35b, as shown in FIG. 7 . The angle δ may be the same as or different from the angle γ. 6 , in the semiconductor manufacturing equipment member 10B, the maximum diameter Pmax (in this example, the diameter of the lower end 25b of the outer peripheral surface 25) of the central ceramic member 22 is smaller than the maximum diameter Qmax (in this example, the diameter of the lower end 35b of the inner peripheral surface 35) of the outer peripheral ceramic member 32, and is larger than the minimum diameter Qmin (in this example, the diameter of the upper end 35a of the inner peripheral surface 35) of the inner peripheral surface 35 of the outer peripheral ceramic member 32. Therefore, in a plan view of the semiconductor manufacturing equipment member 10B, the outer peripheral portion 26 of the central ceramic member 22 and the inner peripheral portion 36 of the outer peripheral ceramic member 32 overlap. Note that, in a plan view of the semiconductor manufacturing equipment member 10B, the outer peripheral surface 25 of the central ceramic member 22 is located between the wafer mounting surface 22a and the FR mounting surface 32a, and it is not possible to see through it. In this semiconductor manufacturing equipment member 10B, as shown in Fig. 7, accelerated ions collide with the ceramic member 20 before reaching the base member 40 or the bonding portion 60 and do not proceed beyond that. This suppresses the generation of plasma and radicals around the base member 40 or the bonding portion 60, suppressing corrosion of the base member 40 or the bonding portion 60, and as a result, suppressing a decrease in the life of the equipment. Furthermore, even when waferless dry cleaning is performed without placing an FR 70 on the FR mounting surface 32a, corrosion of the base member 40 or the bonding portion 60 can be suppressed, thereby improving the life of the FR 70 and suppressing a decrease in the life of the entire semiconductor manufacturing equipment.

[0044] In the semiconductor manufacturing equipment member 10B, the minimum diameter Pmin of the outer peripheral surface 25 of the central ceramic member 22 (in this embodiment, the diameter of the upper end 25a of the outer peripheral surface 25) is smaller than the minimum diameter Qmin of the inner peripheral surface 35 of the outer peripheral ceramic member 32. The central ceramic member 22 and the outer peripheral ceramic member 32 can be produced, for example, by hollowing out a single ceramic plate.

[0045] The central ceramic member 22 and the peripheral ceramic member 32 of the semiconductor manufacturing equipment member 10B may be manufactured in accordance with Fig. 4. In this case, when hollowing out the central portion of the disk-shaped member in Fig. 4B, the central portion of the disk-shaped member may be machined to have a truncated cone shape.

[0046] In the above-described embodiment and other examples, the central joint portion 62 and the outer peripheral joint portion 67 are resin adhesive layers. However, they may be metallic joint layers formed of, for example, solder or a metal brazing material. The metallic joint layer may be formed, for example, by thermal compression bonding (TCB). TCB refers to a known method in which a metallic joint material is sandwiched between two components to be joined and the two components are pressure-bonded while heated to a temperature below the solidus temperature of the metallic joint material. When the central joint portion 62 and the outer peripheral joint portion 67 are metallic joint layers, as in another example semiconductor manufacturing equipment member 10C shown in FIG. 8 , the outer peripheral surface of the central joint portion 62, together with the outer peripheral surface of the central base member 42 serving as a central support member, may be covered with a central insulating film 77, and the outer peripheral surface of the outer peripheral joint portion 67, together with the inner peripheral surface of the outer peripheral base member 52 serving as a peripheral support member, may be covered with an outer peripheral insulating film 78. Furthermore, the outer peripheral surface of the outer peripheral joint 67 may be covered with an outermost insulating film 79 along with the outer peripheral surface of the outer peripheral base member 52 serving as the outer peripheral support member. In this way, the joint 60 and the base member 40 are covered with an insulating film, which further suppresses corrosion of the joint 60 and the base member 40. Furthermore, because the joint 60 is made of metal rather than resin, the joint 60 is less likely to deteriorate even if an insulating film is formed by thermal spraying or the like. In Figure 8, the same components as those in the above-described embodiment are designated by the same reference numerals.

[0047] In the above-described embodiment and other examples, the base member 40 is configured with a central base member 42 as a central support member and a peripheral base member 52 as a peripheral support member, each of which is a separate body. However, the base member 40 may be configured as an integrated unit. In this case, the base member 40 may be configured as an integrated unit in which the central base member 42 and the peripheral base member 52 are connected by a connecting portion 48, as in the semiconductor manufacturing equipment member 10D shown in FIG. 9 . In the semiconductor manufacturing equipment member 10D, an insulating film similar to the central insulating film 77 and the peripheral insulating film 78 is preferably provided on the upper surface of the connecting portion 48. While the base member 40 does not require a gap between the central base member 42 and the peripheral base member 52, providing a gap facilitates independent temperature control of the peripheral base member 52 and the central base member 42, thereby facilitating independent temperature control of the wafer mounting surface 22a and the FR mounting surface 32a. In FIG. 9 , the same components as those in the above-described embodiment are designated by the same reference numerals.

[0048] In the above-described embodiment and other examples, the peripheral ceramic member 32 is disposed with a gap between it and the central ceramic member 22. However, it may be disposed without a gap (including a case where the bonding portion 60 and the base member 40 are covered with a thermal sprayed film and no gap is formed). Disposing the peripheral ceramic member 32 with a gap makes it easier to individually control the temperatures of the wafer mounting surface 22 a and the focus ring mounting surface 32 a. Disposing the peripheral ceramic member 32 with no gap can suppress abnormal discharge that may occur around the base member 40 through the gap when a high-frequency voltage is applied between the shower head 82 and the base member 40.

[0049] In the above-described embodiment and other examples, semiconductor manufacturing equipment components 10, 10B, 10C, and 10D include an annular peripheral ceramic member 32 having a focus ring mounting surface 32a on its upper surface and configured to be disposed on the outer periphery of a central ceramic member having a wafer mounting surface; and a conductive base member 40 bonded to the lower surface of peripheral ceramic member 32 and having an outer support portion for supporting peripheral ceramic member 32. The inner peripheral surface 35 of peripheral ceramic member 32 may have a diameter that varies in the vertical direction, and may be a tapered surface whose diameter increases or decreases toward the upper end, for mounting focus ring 70. In this case, the central ceramic member may be the same as or different from central ceramic member 22 described above, or may be omitted. Furthermore, base member 40 may be the same as base member 40 described above, or may have a central support portion different from central base member 42 described above, or may not have a central support portion.

[0050] In the above-described embodiment and other examples, a heater electrode for heating a wafer may be embedded in the central ceramic member 22. In this case, when it is necessary to heat the wafer W placed on the wafer mounting surface 22a, the heater electrode for heating the wafer can be energized to heat the wafer W to the desired high temperature. Also, a heater electrode for heating the FR may be embedded in the peripheral ceramic member 32. In this case, when it is necessary to heat the FR 70 placed on the FR mounting surface 32a, the heater electrode for heating the FR can be energized to heat the FR 70 to the desired high temperature. When the heater electrode for heating a wafer is embedded in the central ceramic member 22 and the heater electrode for heating the FR is embedded in the peripheral ceramic member 32, it is preferable that the temperatures of the respective heater electrodes be individually adjustable.

[0051] The present invention can be used for components used in semiconductor manufacturing equipment, such as electrostatic chuck heaters, electrostatic chucks, and ceramic heaters.

[0052] 10, 10B, 10C, 10D Semiconductor manufacturing equipment member, 20 Ceramic member, 21 Ceramic plate, 22 Central ceramic member, 22a Wafer mounting surface, 24 Wafer suction electrode, 25 Outer peripheral surface, 26 Outer peripheral portion, 32 Peripheral ceramic member, 32a FR mounting surface, 34 FR suction electrode, 35 Inner peripheral surface, 36 Inner peripheral portion, 40 Base member, 41 Screw hole, 42 Central base member, 42a Central support surface, 44 Central coolant flow path, 48 Connection portion, 52 Peripheral base member, 52a Peripheral support surface, 54 Peripheral coolant flow path, 60 Bonding portion, 62 Central bonding portion, 67 Peripheral bonding portion, 70 Focus ring (FR), 72 Step, 77 Central insulating film, 78 Peripheral insulating film, 79 Outermost peripheral insulating film, 80 Chamber, 82 Shower head, 84 Installation plate, 86 Bolt insertion hole, 87, 88, 89 O-ring, 90 bolt, 110 semiconductor manufacturing equipment member, 120 ceramic member, 122 central ceramic member, 125 outer peripheral surface, 125s step, 132 outer peripheral ceramic member, 132a FR mounting surface, 135 inner peripheral surface, 140 base member, 142 central base member, 152 outer peripheral base member, 160 joint portion, 162 central joint portion, 167 outer peripheral joint portion, 170 FR.

Claims

1. A component for semiconductor manufacturing equipment comprising: a central ceramic member having a wafer mounting surface on its upper surface; a ring-shaped peripheral ceramic member having a focus ring mounting surface on its upper surface and disposed on the outer periphery of the central ceramic member; a central support part joined to the underside of the central ceramic member and supporting the central ceramic member, and a peripheral support part joined to the underside of the peripheral ceramic member and supporting the peripheral ceramic member, wherein the central support part and the peripheral support part are either separate or integral with each other; wherein the diameters of the outer periphery of the central ceramic member and the inner periphery of the peripheral ceramic member both change in the vertical direction, and the maximum diameter of the outer periphery of the central ceramic member is smaller than the maximum diameter of the inner periphery of the peripheral ceramic member and is larger than the minimum diameter of the inner periphery of the peripheral ceramic member.

2. The semiconductor manufacturing equipment member according to claim 1, wherein the minimum diameter of the outer circumferential surface of the central ceramic member is smaller than the minimum diameter of the inner circumferential surface of the outer circumferential ceramic member.

3. A semiconductor manufacturing equipment member according to claim 1 or 2, wherein in a cross section of the semiconductor manufacturing equipment member cut in a direction perpendicular to the wafer mounting surface, the outer peripheral surface of the central ceramic member and the inner peripheral surface of the outer peripheral ceramic member each appear as an oblique line.

4. A semiconductor manufacturing equipment member according to claim 1 or 2, wherein the outer circumferential surface of the central ceramic member is a tapered surface whose diameter increases toward the upper side.

5. A semiconductor manufacturing equipment member according to claim 1 or 2, wherein the outer circumferential surface of the central ceramic member is a tapered surface whose diameter decreases toward the upper side.

6. A semiconductor manufacturing equipment member according to claim 1 or 2, wherein the outer peripheral support portion is an annular portion disposed on the outer periphery of the central support portion with a gap therebetween.

7. A semiconductor manufacturing equipment member as described in claim 6, wherein the central ceramic member and the central support are joined by a metallic central joint, the outer peripheral surface of which, together with the outer peripheral surface of the central support, is covered by a central insulating film, and the outer peripheral ceramic member and the outer peripheral support are joined by a metallic peripheral joint, the inner peripheral surface of which, together with the inner peripheral surface of the outer peripheral support, is covered by an outer peripheral insulating film.

8. A semiconductor manufacturing equipment component as claimed in claim 1 or 2, wherein the central ceramic member and the central support portion are joined by a central joint made of resin, and the peripheral ceramic member and the peripheral support portion are joined by a peripheral joint made of resin.

9. A member for semiconductor manufacturing equipment for mounting a focus ring, comprising: an annular peripheral ceramic member having a focus ring mounting surface on an upper surface thereof and configured to be positionable on the outer circumferential side of a central ceramic member having a wafer mounting surface; and a conductive base member joined to the underside of the peripheral ceramic member and having an outer circumferential support portion for supporting the peripheral ceramic member, wherein the inner circumferential surface of the peripheral ceramic member has a diameter that changes in the vertical direction, and the inner circumferential surface of the peripheral ceramic member is a tapered surface whose diameter increases toward the upper side or decreases toward the upper side.

Images