Component for semiconductor manufacturing apparatus and method for manufacturing the same

Abstract

The present invention provides a member for a semiconductor manufacturing apparatus formed by metal-bonding an upper plate, an intermediate plate, and a lower plate, which member has good bondability and is not easily broken. The member (10) for a semiconductor manufacturing apparatus of the present invention includes: a ceramic upper plate (20) having a wafer placement surface (22) and internally provided with electrostatic electrodes (24) and upper auxiliary electrodes (26) that are parallel to each other; an intermediate plate (30) bonded to a surface (23) of the upper plate (20) opposite to the wafer placement surface (22) via a first metal bonding layer (31); and a lower plate (40) bonded to a surface of the intermediate plate (30) opposite to the surface bonded to the upper plate (20) via a second metal bonding layer (32) and internally provided with heating electrodes (44) and lower auxiliary electrodes (46) that are parallel to each other.

Description

Technical Field

[0001] The present invention relates to a member for a semiconductor manufacturing apparatus and a method for manufacturing the same. Background Art

[0002] Conventionally, as a member for a semiconductor manufacturing apparatus, a member for a semiconductor manufacturing apparatus is known, which includes: an upper plate made of ceramics, in which an electrostatic electrode and a heating electrode are built; an intermediate plate made of a metal base material, which is joined to a surface of the upper plate on the side opposite to the wafer mounting surface via a first metal bonding layer; and a lower plate made of ceramics, which is joined to a surface of the intermediate plate on the side opposite to the surface joined to the upper plate via a second metal bonding layer (for example, Patent Document 1). In Patent Document 1, the upper positioning disk plate corresponds to the upper plate, the lower positioning disk plate corresponds to the intermediate plate, and the back plate corresponds to the lower plate.

[0003] [Prior Art Documents]

[0004] [Patent Documents]

[0005] [Patent Document 1] Japanese Patent Application Laid-Open No. 2018-518833 Summary of the Invention

[0006] [Problems to be Solved by the Invention]

[0007] However, in the above-described member for a semiconductor manufacturing apparatus, both the electrostatic electrode and the heating electrode are built in the upper plate, but sometimes it is desired to build the electrostatic electrode in the upper plate and the heating electrode in the lower plate. In this case, the electrostatic electrode is built in a position of the upper plate close to the wafer mounting surface, and the heating electrode is built in a position of the lower plate close to the bonding surface. In addition, when manufacturing such a member for a semiconductor manufacturing apparatus, the upper plate, the intermediate plate, and the lower plate are manufactured separately, and then these plates are metal-bonded.

[0008] However, if the electrostatic electrode is built in a position of the upper plate close to the wafer mounting surface, after manufacturing the upper plate by sintering, the upper plate sometimes deforms due to the difference in thermal expansion coefficient between the electrostatic electrode and the ceramics constituting the upper plate. If the heating electrode is built in a position of the lower plate close to the bonding surface, after manufacturing the lower plate by sintering, the lower plate sometimes deforms due to the difference in thermal expansion coefficient between the heating electrode and the ceramics constituting the lower plate. If the deformed upper plate, the deformed lower plate, and the intermediate plate are metal-bonded, there may be a partial load and the bonding property may deteriorate, or residual stress may be generated due to the restoring force of the warpage and the plate may be damaged.

[0009] The present invention was completed to solve such problems, and its main object is to provide a member for a semiconductor manufacturing apparatus that has good bonding properties and is not easily damaged, in a member for a semiconductor manufacturing apparatus formed by metal-bonding an upper plate, an intermediate plate, and a lower plate.

[0010] [Solution to the Problem]

[0011] The member for a semiconductor manufacturing apparatus of the present invention includes:

[0012] An upper plate made of ceramic, which has a wafer placement surface and in which electrostatic electrodes and upper auxiliary electrodes parallel to each other are built in;

[0013] An intermediate plate, which is bonded to the surface of the upper plate on the side opposite to the wafer placement surface via a first metal bonding layer; and

[0014] A lower plate, which is bonded to the surface of the intermediate plate on the side opposite to the surface bonded to the upper plate via a second metal bonding layer, and in which heating electrodes and lower auxiliary electrodes parallel to each other are built in.

[0015] In this member for a semiconductor manufacturing apparatus, since electrostatic electrodes and upper auxiliary electrodes parallel to each other are built in the ceramic upper plate, it is easier to become flat compared to the case where only electrostatic electrodes are built in. In addition, since heating electrodes and lower auxiliary electrodes parallel to each other are built in the lower plate, it is easier to become flat compared to the case where only heating electrodes are built in. As a result, when the upper plate, the intermediate plate, and the lower plate are metal-bonded, an uneven load is less likely to occur, and the bonding properties become good. In addition, since the upper plate and the lower plate are not warped or hardly warped, the generation of residual stress caused by the restoring force of warping can be prevented, and it is not easily damaged.

[0016] It should be noted that "parallel" is regarded as parallel not only in the case of complete parallelism, but also as long as it is within the tolerance range even if it is not completely parallel (the same applies hereinafter). In addition, "upper" and "lower" do not represent an absolute positional relationship, but a relative positional relationship. Therefore, depending on the orientation of the member for a semiconductor manufacturing apparatus, "upper" and "lower" may become "left" and "right", or may become "front" and "back", or may become "lower" and "upper" (the same applies hereinafter).

[0017] In the member for a semiconductor manufacturing apparatus of the present invention, the upper auxiliary electrode may be an electrode electrically connected to the electrostatic electrode via a through hole built in the upper plate, may be an electrode electrically connected to the intermediate plate, or may be an independent electrode that is neither electrically connected to the electrostatic electrode nor electrically connected to the intermediate plate.

[0018] In the component for a semiconductor manufacturing apparatus of the present invention, the lower auxiliary electrode may be an electrode electrically connected to the heating electrode via a through hole provided in the lower plate, or may be an independent electrode that is neither electrically connected to the heating electrode nor electrically connected to the intermediate plate.

[0019] In the component for a semiconductor manufacturing apparatus of the present invention, the thickness of the electrostatic electrode, the thickness of the upper auxiliary electrode, the arrangement position of the electrostatic electrode in the upper plate, and the arrangement position of the upper auxiliary electrode in the upper plate may be set such that the upper plate becomes flat, and the thickness of the heating electrode, the thickness of the lower auxiliary electrode, the arrangement position of the heating electrode in the lower plate, and the arrangement position of the lower auxiliary electrode in the lower plate may be set such that the lower plate becomes flat. It should be noted that "flat" is regarded as flat even if it is not completely flat as long as it is within the tolerance range (the same applies hereinafter).

[0020] In the component for a semiconductor manufacturing apparatus of the present invention, the materials and thicknesses of the electrostatic electrode and the upper auxiliary electrode may be the same, the distance from the wafer placement surface of the upper plate to the electrostatic electrode may be the same as the distance from the surface on the opposite side of the wafer placement surface to the upper auxiliary electrode, the materials and thicknesses of the heating electrode and the lower auxiliary electrode may be the same, and the distance from the bonding surface of the lower plate to the heating electrode may be the same as the distance from the surface on the opposite side of the bonding surface to the lower auxiliary electrode. In this way, the upper plate and the lower plate are likely to become flat.

[0021] In the component for a semiconductor manufacturing apparatus of the present invention, the outer diameter of the electrostatic electrode and the outer diameter of the upper auxiliary electrode may be the same, and the outer diameter of the heating electrode and the outer diameter of the lower auxiliary electrode may be the same. In addition, the so-called "same" is regarded as the same even if it is not completely the same as long as it is within the tolerance range (the same applies hereinafter).

[0022] In the component for a semiconductor manufacturing apparatus of the present invention, the intermediate plate may be made of a composite material of metal and ceramic or made of metal, and the lower plate may be made of the same ceramic as the upper plate.

[0023] The manufacturing method of the component for a semiconductor manufacturing apparatus of the present invention includes:

[0024] (a) A step of preparing an upper plate, a lower plate, and an intermediate plate, wherein the upper plate is made of ceramic, has a wafer placement surface, and has an electrostatic electrode and an upper auxiliary electrode that are parallel to each other built therein, and the lower plate has a heating electrode and a lower auxiliary electrode that are parallel to each other built therein; and

[0025] (b) A step of obtaining a bonded body by disposing a first metal bonding material between the upper surface of the intermediate plate and the surface of the upper plate on the side opposite to the wafer mounting surface, and disposing a second metal bonding material between the lower surface of the intermediate plate and the upper surface of the lower plate, and then heating under pressure and returning to room temperature in this state.

[0026] The method for manufacturing the component for a semiconductor manufacturing apparatus is suitable for manufacturing the above-mentioned component for a semiconductor manufacturing apparatus. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 It is a cross-sectional view of the component 10 for a semiconductor manufacturing apparatus.

[0028] Figure 2 It is a top view of the wafer mounting surface 22.

[0029] Figure 3 It is a top view showing an example of the electrostatic electrode 24 buried in the upper plate 20.

[0030] Figure 4 It is a top view showing an example of the upper auxiliary electrode 26 buried in the upper plate 20.

[0031] Figure 5 It is a top view showing an example of the upper auxiliary electrode 26 buried in the upper plate 20.

[0032] Figure 6 It is a top view showing an example of the upper auxiliary electrode 26 buried in the upper plate 20.

[0033] Figure 7 It is a top view showing an example of the heating electrode 44 buried in the lower plate 40.

[0034] Figure 8 It is a cross-sectional view showing the state when the component 10 for a semiconductor manufacturing apparatus is mounted on the cooling device 50.

[0035] Figures 9A to 9D It is a manufacturing process diagram of the upper plate 20.

[0036] Figures 10A to 10D It is a manufacturing process diagram of the component 10 for a semiconductor manufacturing apparatus.

[0037] Figure 11 It is a partial cross-sectional view showing another example of the upper plate 20.

[0038] Figure 12 It is a partial cross-sectional view showing another example of the upper plate 20.

[0039] Figure 13 It is a partial cross-sectional view showing another example of the lower plate 40.

[0040] [Description of Symbols]

[0041] 10: Component for semiconductor manufacturing apparatus, 20: Upper plate, 22: Wafer placement surface, 22a: Sealing tape, 22b: Circular protrusion, 24: Electrostatic electrode, 26: Upper auxiliary electrode, 27: Dielectric layer, 28, 29: Through hole, 30: Intermediate plate, 31: First metal bonding layer, 32: Second metal bonding layer, 40: Lower plate, 42: Upper surface, 43: Lower surface, 44: Heating electrode, 44a: One end, 44b: The other end, 46: Lower auxiliary electrode, 48: Through hole, 50: Cooling device, 52: Refrigerant passage, 54: Circular groove, 56: Annular surface, 57: Sealing member, 58: Threaded hole, 59: Screw insertion hole, 60: Collar, 62: Step, 64: Longitudinal hole, 65, 67: Screw, 66: Threaded hole, 70: Laminate, 71: First MC sheet, 72: Second MC sheet, 73: Third MC sheet, 73: Laminate, 76: Alumina sintered body, 80: Bonded body, 301: First metal bonding material, 302: Second metal bonding material. Detailed Description of the Invention

[0042] Hereinafter, preferred embodiments of the present invention will be described with reference to the accompanying drawings. Figure 1 is a cross-sectional view of the component 10 for a semiconductor manufacturing apparatus (a cross-sectional view when cut along a vertical plane passing through the center of the component 10), Figure 2 is a top view of the wafer placement surface 22, Figure 3 is a top view showing an example of the electrostatic electrode 24, Figures 4 to 6 is a top view showing an example of the upper auxiliary electrode 26, Figure 7 is a top view showing an example of the heating electrode 44.

[0043] As Figure 1 shown, the component 10 for a semiconductor manufacturing apparatus includes an upper plate 20, an intermediate plate 30, a lower plate 40, and first and second metal bonding layers 31, 32.

[0044] The upper plate 20 is a disk-shaped plate made of ceramics (e.g., alumina, aluminum nitride) with the same diameter as the silicon wafer W on which plasma treatment is performed, and has an electrostatic electrode 24 and an upper auxiliary electrode 26 built therein. Therefore, the upper plate 20 functions as an electrostatic chuck. The diameter of the upper plate 20 is not particularly limited, and can be set to, for example, 250 to 350 mm. The upper surface of the upper plate 20 becomes the wafer placement surface 22. As Figure 2 shown, a sealing tape 22a is formed along the outer edge on the wafer placement surface 22, and a plurality of circular protrusions 22b are formed on the entire surface. The sealing tape 22a and the circular protrusions 22b have the same height, and the height is, for example, several μm to several tens of μm.

[0045] AsFigure 3 As shown, the electrostatic electrode 24 is a circular surface electrode concentric with the upper plate 20, and its diameter is slightly smaller than the diameter of the upper plate 20. The electrostatic electrode 24 can apply a DC voltage through an external power supply via a power supply terminal (not shown). The portion between the wafer mounting surface 22 and the electrostatic electrode 24 in the upper plate 20 functions as a dielectric layer 27 (see Figure 1 ). The thickness of the dielectric layer 27 is adjusted to a predetermined thickness (for example, 50 to 500 μm) in consideration of the force for adsorbing the wafer W. When a DC voltage is applied to the electrostatic electrode 24, the wafer W placed on the wafer mounting surface 22 is adsorbed and fixed to the wafer mounting surface 22, and when the application of the DC voltage is released, the adsorption and fixation of the wafer to the wafer mounting surface 22 is released. The back surface of the wafer W adsorbed on the wafer mounting surface 22 contacts the upper surface of the sealing tape 22a and the upper surface of the circular protrusion 22b. In addition, a space is formed between the back surface of the wafer W and the portion of the wafer mounting surface 22 where the sealing tape 22a and the circular protrusion 22b are not provided. A heat conductive gas (for example, He gas) is supplied to this space through a gas supply path (not shown) that penetrates the semiconductor manufacturing apparatus member 10 in the vertical direction. Heat exchange between the upper plate 20 and the wafer W is efficiently performed using this heat conductive gas.

[0046] The upper auxiliary electrode 26 is an electrode having the same (or substantially the same) shape as the electrostatic electrode 24 in a plan view. For example, the upper auxiliary electrode 26 may be a circular surface electrode having the same shape as the electrostatic electrode 24 in a plan view, or may be a shape obtained by dividing the circular surface electrode by one or more concentric circumferences (for example, Figure 4 the concentric ring shape), or may be a plurality of sectors obtained by equally or unequally dividing the circular surface electrode by one or more radii (for example, Figure 5 the pie-cut shape), or may be a spiral shape (for example, Figure 6 ). In the present embodiment, the upper auxiliary electrode 26 is an independent electrode that is neither electrically connected to the electrostatic electrode 24 nor electrically connected to the intermediate plate 30. The upper auxiliary electrode 26 may be grounded.

[0047] The electrostatic electrode 24 and the upper auxiliary electrode 26 are arranged in parallel with the wafer mounting surface 22. The electrostatic electrode 24 and the upper auxiliary electrode 26 may be made of different materials or the same material, but preferably the same material. Examples of the material include high melting point metals such as tungsten, molybdenum, tantalum, platinum, rhenium, hafnium and their alloys, high melting point metal carbides such as tungsten carbide or molybdenum carbide, mixtures of high melting point metals and ceramics, mixtures of high melting point metal carbides and ceramics, etc. The electrostatic electrode 24 and the upper auxiliary electrode 26 can be formed by printing a conductive paste or by using a conductive plate. When the thickness of the upper plate 20 is set to t1 [mm], the distance from the wafer mounting surface 22 to the electrostatic electrode 24 is set to a1 [mm], the distance from the surface 23 on the side opposite to the wafer mounting surface 22 to the upper auxiliary electrode 26 is set to b1 [mm], the thickness of the electrostatic electrode 24 is set to x1 [μm], and the thickness of the upper auxiliary electrode 26 is set to y1 [μm], it is preferable to satisfy the following relational expressions (1) to (4).

[0048] 4*a1≥b1≥a1…(1)

[0049] 0.5*t1≥a1…(2)

[0050] 0.75*t1≥b1…(3)

[0051] 5*x1≥y1≥x1…(4)

[0052] The intermediate plate 30 is a disk-shaped plate whose diameter is larger than the diameters of the upper plate 20 and the lower plate 40. The intermediate plate 30 is joined to the surface 23 of the upper plate 20 on the side opposite to the wafer mounting surface 22 via the first metal bonding layer 31. Examples of the material of the intermediate plate 30 include composite materials, metals, etc. Examples of the composite material include metal matrix composites (also referred to as metal matrix composites (MMC)). Examples of MMC include materials containing Si, SiC and Ti (also referred to as SiSiCTi), materials obtained by impregnating SiC porous bodies with Al and / or Si, etc. Examples of the metal include Ti, Mo, etc.

[0053] The lower plate 40 is a circular plate-shaped ceramic plate having the same diameter as the upper plate 20, and a heating electrode 44 and a lower auxiliary electrode 46 are provided therein. The lower plate 40 is joined to the surface of the intermediate plate 30 on the side opposite to the surface joined to the upper plate 20 via the second metal bonding layer 32.

[0054] As Figure 7As shown, the heating electrode 44 is formed in a pattern across substantially the entire surface of the area when looking down at the lower plate 40, from one end 44a to the other end 44b in one stroke. When a voltage is applied, it generates heat to heat the wafer W. The area where the heating electrode 44 is wired is a circular area when looking down. The heating electrode 44 can apply a voltage via a power supply terminal (not shown) connected to one end 44a and the other end 44b through a heating power supply.

[0055] The lower auxiliary electrode 46 has the same (or substantially the same) shape as the heating electrode 44 when looking down. For example, the lower auxiliary electrode 46 can be a circular surface electrode that is the same as the circular area where the heating electrode 44 is wired when looking down, or it can be a concentric ring shape ( Figure 4 ), a pie-cut shape ( Figure 5 ), or a spiral shape ( Figure 6 ) as an example of the upper auxiliary electrode 26. In the present embodiment, the lower auxiliary electrode 46 is an independent electrode that is neither electrically connected to the heating electrode 44 nor to the intermediate plate 30. The lower auxiliary electrode 46 can also be grounded. In this case, the lower auxiliary electrode 46 can be used as an electrode to shield the heating electrode 44 from the plasma.

[0056] The heating electrode 44 and the lower auxiliary electrode 46 are provided parallel to the upper surface 42 of the lower plate 40. The heating electrode 44 and the lower auxiliary electrode 46 can be made of different materials or the same material, but preferably the same material. Examples of materials include high melting point metals such as tungsten, molybdenum, tantalum, platinum, rhenium, hafnium, and their alloys, high melting point metal carbides such as tungsten carbide or molybdenum carbide, mixtures of high melting point metals and ceramics, and mixtures of high melting point metal carbides and ceramics. The heating electrode 44 and the lower auxiliary electrode 46 are preferably formed by printing a conductive paste. When the thickness of the lower plate 40 is set to t2 [mm], the distance from the upper surface 42 to the heating electrode 44 is set to a2 [mm], the distance from the lower surface 43 to the lower auxiliary electrode 46 is set to b2 [mm], the thickness of the heating electrode 44 is set to x2 [μm], and the thickness of the lower auxiliary electrode 46 is set to y2 [μm], the following relational expressions (5) to (8) are preferably satisfied.

[0057] 4*a2≥b2≥a2…(5)

[0058] 0.5*t2≥a2…(6)

[0059] 0.75*t2≥b2…(7)

[0060] 5*x2≥y2≥x2…(8)

[0061] When the materials of the upper plate 20 and the lower plate 40 are alumina, the material of the intermediate plate 30 is preferably SiSiCTi or metal Ti. When the materials of the upper plate 20 and the lower plate 40 are aluminum nitride, the material of the intermediate plate 30 is preferably a material obtained by impregnating Si into a SiC porous body or metal Mo.

[0062] The first and second metal bonding layers 31, 32 are made of an Al-containing material such as an Al-Si-Mg-based or Al-Mg-based material, for example. The thicknesses of the first and second metal bonding layers 31, 32 are not particularly limited, and are preferably 1 to 300 μm, more preferably 50 to 150 μm. Further, it is preferable that the outer periphery of the first metal bonding layer 31 does not protrude from the outer periphery of the upper plate 20, and it is preferable that the outer periphery of the second metal bonding layer 32 does not protrude from the outer periphery of the lower plate 40. The first and second metal bonding layers 31, 32 are formed by, for example, thermal compression bonding (TCB). TCB is a known method in which a metal bonding material is sandwiched between two members to be joined, and the two members are pressure-joined while being heated to a temperature below the solidus temperature of the metal bonding material.

[0063] Next, a usage example of the member 10 for a semiconductor manufacturing apparatus will be described. Figure 8FIG. 0 is a cross-sectional view showing the state when the member 10 for a semiconductor manufacturing apparatus is mounted on the cooling device 50. First, the member 10 for a semiconductor manufacturing apparatus is mounted on the cooling device 50 provided in a vacuum chamber (not shown). The cooling device 50 is a disk member made of a metal such as aluminum, and has a refrigerant passage 52 inside through which a refrigerant can circulate. A circular groove 54 is provided at the center of the upper surface of the cooling device 50. The lower plate 40 is inserted into the circular groove 54. The cooling device 50 has an annular surface 56 surrounding the periphery of the circular groove 54. The member 10 for a semiconductor manufacturing apparatus is fixed to the cooling device 50 by a clamping ring 60 in a state where an annular sealing member 57 is disposed between the outer peripheral portion of the lower surface of the intermediate plate 30 and the annular surface 56, and the lower plate 40 is inserted into the circular groove 54. The outer diameter of the sealing member 57 is larger than the diameter of the circular groove 54 and smaller than the diameter of the intermediate plate 30. As the sealing member 57, for example, a metal gasket or the like can be cited. The clamping ring 60 is disposed on the annular surface 56 of the cooling device 50. A step 62 is provided on the inner peripheral surface of the clamping ring 60, and the step 62 presses the upper surface of the outer peripheral portion of the intermediate plate 30 from above. In addition, the clamping ring 60 has a longitudinal hole 64 through which a screw 65 can be inserted and a threaded hole 66 that can be screwed with a screw 67. The screw 65 is inserted into the longitudinal hole 64 from above and screwed with a threaded hole 58 provided on the annular surface 56 of the cooling device 50. The screw 67 is inserted into a screw insertion hole 59 that penetrates the cooling device 50 in the vertical direction from below and screwed with the threaded hole 66 provided on the back surface of the clamping ring 60. A plurality (for example, 8) of such screws 65 and 67 are provided at equal intervals in the circumferential direction of the clamping ring 60. Thus, the space S surrounded by the circular groove 54, the lower plate 40, and the sealing member 57 is sealed. A heat conductive sheet or a heat conductive gas is filled in the sealed space S. In this way, the portions of the intermediate plate 30 of the member 10 for a semiconductor manufacturing apparatus that protrude outward from the upper plate 20 and the lower plate 40 are used as flanges for mounting on the cooling device 50.

[0064] After the member 10 for a semiconductor manufacturing apparatus is mounted on the cooling device 50, the wafer W is placed on the wafer placement surface 22. Then, the vacuum chamber is evacuated by a vacuum pump to adjust to a predetermined vacuum level, and a DC voltage is applied to the electrostatic electrode 24 to adsorb and fix the wafer W on the wafer placement surface 22. The wafer W is in contact with the sealing tape 22a and the circular protrusion 22b (see Figure 2)Sealing is achieved. Thus, the space between the back surface of the wafer W and the portion of the wafer mounting surface 22 where the sealing tape 22a and the circular protrusion 22b are not provided is sealed. A heat-conducting gas is supplied to this space. Since the heat-conducting gas is enclosed, efficient heat conduction can be carried out between the upper plate 20 and the wafer W. Next, the reaction gas atmosphere in the vacuum chamber is set to a predetermined pressure (e.g., several tens to several hundreds of Pa), and plasma is generated in this state. Then, the surface of the wafer W is etched using the generated plasma. A controller (not shown) controls the power supplied to the heating electrode 44 so that the temperature of the wafer W becomes a preset target temperature.

[0065] Next, a manufacturing example of the member 10 for a semiconductor manufacturing apparatus will be described. Figures 9A to 9D is a manufacturing process diagram of the upper plate 20, Figures 10A to 10D is a manufacturing process diagram of the member 10 for a semiconductor manufacturing apparatus. Hereinafter, the case where the material of the upper plate 20 and the lower plate 40 is alumina and the material of the intermediate plate 30 is SiSiCTi will be described as an example.

[0066] First, prepare the upper plate 20, the intermediate plate 30, and the lower plate 40 (refer to Figure 10A ). This process is referred to as process (a).

[0067] The upper plate 20 can be manufactured as follows. Here, a Figures 9A to 9D manufacturing example of the alumina upper plate 20 will be described. First, prepare disk-shaped first to third MC sheets 71 to 73 made of alumina. MC is an abbreviation for molded casting, which refers to a well-known method of injecting a ceramic slurry containing a ceramic raw material powder (here, an alumina raw material powder) and a molding agent into a molding die, and causing a chemical reaction of the molding agent in the molding die to mold the ceramic slurry, thereby obtaining a molded body. As the molding agent, for example, isocyanate and polyol can be included and molded through an urethane esterification reaction. Next, an electrostatic electrode 24 is formed on the surface of the second MC sheet 72, and an upper auxiliary electrode 26 is formed on the surface of the third MC sheet 73 (refer to Figure 9A ). As a method for forming the electrostatic electrode 24 and the upper auxiliary electrode 26, for example, screen printing, PVD, CVD, plating, etc. can be used. Next, the second MC sheet 72 is laminated on the surface of the third MC sheet 73 where the upper auxiliary electrode 26 is formed with the electrostatic electrode 24 facing upward, and the first MC sheet 71 is laminated thereon to form a laminate 70 (refer to Figure 9B ). Next, the laminate 70 is fired by a hot pressing method to obtain an alumina sintered body 76 in which the electrostatic electrode 24 and the upper auxiliary electrode 26 are embedded (refer to Figure 9C ). By performing grinding or sandblasting on both surfaces of the obtained alumina sintered body 76 to adjust the shape and thickness, a flat upper plate 20 is obtained (refer toFigure 9D and Figure 10A ). At this time, the thickness of the dielectric layer 27 is processed to a predetermined thickness, but the sealing band 22a and the circular protrusion 22b are not formed on the wafer mounting surface 22. It should be noted that a green sheet can also be used instead of the alumina-based MC sheet.

[0068] The intermediate plate 30 can be manufactured in the following manner. Here, a manufacturing example of the SiSiCTi-based intermediate plate 30 will be described. First, a disk member made of SiSiCTi is produced. For example, a powder mixture is produced, which contains 39 to 51% by mass of silicon carbide raw material particles having an average particle size of 10 μm or more and 25 μm or less, and contains one or more raw materials selected in such a way as to include Ti and Si. For Si and Ti derived from raw materials other than silicon carbide, the mass ratio of Si / (Si + Ti) is 0.26 to 0.54. As raw materials, for example, silicon carbide, metallic Si, and metallic Ti can be used. In this case, it is preferably mixed in such a way that silicon carbide is 39 to 51% by mass, metallic Si is 16 to 24% by mass, and metallic Ti is 26 to 43% by mass. Then, the obtained powder mixture is made into a disk-shaped compact by uniaxial pressing, and the compact is sintered at 1370 to 1460 °C by hot pressing in an inert atmosphere, thereby obtaining a disk member made of SiSiCTi. In addition, the pressing pressure during hot pressing is set to, for example, 50 to 300 kgf / cm 2 . Then, the shape and thickness of the obtained disk member are adjusted by grinding or the like to obtain the intermediate plate 30 (refer to Figure 10A ). Regarding the specific manufacturing conditions of the intermediate plate 30, for example, they can be set by referring to the conditions described in Japanese Patent No. 5666748.

[0069] The lower plate 40 can be manufactured in the following manner. Here, a manufacturing example of the alumina-based lower plate 40 will be described. First, in the same manner as in the case of manufacturing the upper plate 20, disk-shaped first to third MC sheets made of alumina are prepared. Then, a heating electrode 44 is formed on the surface of the second MC sheet, and a lower auxiliary electrode 46 is formed on the surface of the third MC sheet. As a method for forming the heating electrode 44 and the lower auxiliary electrode 46, for example, screen printing, PVD, CVD, plating, etc. can be used. Then, the second MC sheet is laminated on the surface of the third MC sheet on which the lower auxiliary electrode 46 is formed with the heating electrode 44 facing upward, and the first MC sheet is laminated thereon to form a laminate. Then, the laminate is fired by a hot pressing method, thereby obtaining an alumina sintered body in which the heating electrode 44 and the lower auxiliary electrode 46 are embedded. By performing grinding or sandblasting on both surfaces of the obtained alumina sintered body to adjust the shape and thickness, a flat lower plate 40 is obtained (refer to Figure 10A)。It should be noted that a green sheet can also be used to replace the MC sheet made of alumina.

[0070] Next, a flat plate-shaped second metal bonding material 302 having the same diameter as the lower plate 40 is placed on the upper surface of the lower plate 40, and the intermediate plate 30 is placed thereon. Further, a flat plate-shaped first metal bonding material 301 having the same diameter as the upper plate 20 is placed on the upper surface of the intermediate plate 30, and it is placed in such a manner that the lower surface of the upper plate 20 is in contact with the second metal bonding material 301. Thus, a sandwich laminate in a state where the intermediate plate 30 is sandwiched between the upper plate 20 and the lower plate 40 with the respective metal bonding materials 301 and 302 interposed therebetween is obtained. Next, the sandwich laminate is pressed at a temperature below the solidus temperature of the first and second metal bonding materials 301 and 302 (for example, a temperature equal to or higher than the temperature obtained by subtracting 20°C from the solidus temperature and equal to or lower than the solidus temperature), and the upper plate 20, the intermediate plate 30, and the lower plate 40 are subjected to TCB bonding (refer to Figure 10B ), and then returned to room temperature. Thus, a bonded body 80 in which the first metal bonding material 301 has become the first metal bonding layer 31 and the second metal bonding material 302 has become the second metal bonding layer 32 is obtained (refer to Figure 10C ). This process is referred to as process (b). As the first and second metal bonding materials 301 and 302, an Al-Mg-based bonding material or an Al-Si-Mg-based bonding material can be used. For example, in the case of performing TCB bonding using an Al-Si-Mg-based bonding material (containing 88.5 wt% of Al, 10 wt% of Si, and 1.5 wt% of Mg, and having a solidus temperature of about 560°C), it is heated to 540 to 560°C (for example, 550°C) in a vacuum atmosphere and pressed at a pressure of 0.5 to 2.0 kg / mm 2 (for example, 1.5 kg / mm 2 ) on the upper plate 20 for several hours. The first and second metal bonding materials 301 and 302 are preferably materials having a thickness of about 100 μm.

[0071] Next, a pattern mask having openings in a portion where the seal band 22a and the circular protrusion 22b are not formed is pasted on the wafer mounting surface 22 of the upper plate 20 of the bonded body 80, and a sandblasting medium is sprayed for sandblasting. By the sandblasting, the seal band 22a and the circular protrusion 22b are formed on the wafer mounting surface 22. This process is referred to as process (c). Then, the mask is removed to obtain a member 10 for a semiconductor manufacturing apparatus (refer to Figure 10D ).

[0072] In the member 10 for a semiconductor manufacturing apparatus described in detail above, the ceramic upper plate 20 has built therein the electrostatic electrode 24 and the upper auxiliary electrode 26 that are parallel to each other. Therefore, it is easier to be flat compared to the case where only the electrostatic electrode is built in. In addition, the ceramic lower plate 40 has built therein the heating electrode 44 and the lower auxiliary electrode 46 that are parallel to each other. Therefore, it is easier to be flat compared to the case where only the heating electrode is built in. As a result, when the upper plate 20, the intermediate plate 30, and the lower plate 40 are metal-bonded, it is not easy to generate an eccentric load, and the bondability becomes good. In addition, since the upper plate 20 and the lower plate 40 do not warp or hardly warp, it is possible to prevent the generation of residual stress caused by the restoring force of the warp, and it is not easy to break.

[0073] In addition, the intermediate plate 30 is made of a composite material of metal and ceramic, and the upper plate 20 and the lower plate 40 are both made of ceramic. Therefore, the member 10 for a semiconductor manufacturing apparatus is not easy to warp.

[0074] Furthermore, the manufacturing method of the member 10 for a semiconductor manufacturing apparatus includes: (a) a step of preparing the upper plate 20, the lower plate 40, and the intermediate plate 30; and (b) a step of disposing the first metal bonding material 301 between the upper surface of the intermediate plate 30 and the surface 23 of the upper plate 20 on the side opposite to the wafer mounting surface 22, and disposing the second metal bonding material 302 between the lower surface of the intermediate plate 30 and the upper surface of the lower plate 40, and performing pressure heating in this state and then returning to room temperature to obtain the bonded body 80. This manufacturing method is suitable for manufacturing the above-described member 10 for a semiconductor manufacturing apparatus.

[0075] It should be noted that the present invention is not limited by any of the above-described embodiments, and as long as it belongs to the technical scope of the present invention, it can of course be implemented in various ways.

[0076] In the above-described embodiment, the upper auxiliary electrode 26 is provided as an independent electrode that is neither electrically connected to the electrostatic electrode 24 nor electrically connected to the intermediate plate 30, but is not particularly limited thereto. For example, as Figure 11 shown, the upper auxiliary electrode 26 may also be electrically connected to the electrostatic electrode 24 via the through hole 28 built in the upper plate 20. In this case, the upper auxiliary electrode 26 may also be used as a jumper for the electrostatic electrode 24. Or, as Figure 12 shown, the upper auxiliary electrode 26 may also be electrically connected to the intermediate plate 30 via the through hole 29. In this case, the upper auxiliary electrode 26 may also be used as an RF electrode by supplying RF power to the intermediate plate 30. In addition, in Figure 11 and Figure 12 the same reference numerals are given to the same constituent elements as those in the above-described embodiment.

[0077] In the above-described embodiment, the lower auxiliary electrode 46 is provided as an independent electrode that is neither electrically connected to the heating electrode 44 nor to the intermediate plate 30, but is not particularly limited thereto. For example, as Figure 13 shown, the lower auxiliary electrode 46 may also be electrically connected to the heating electrode 44 via a through hole 48 provided in the lower plate 40. In this case, the lower auxiliary electrode 46 can also be used as a jumper for the heating electrode 44. In addition, in Figure 13 the same reference numerals are given to the same components as those in the above-described embodiment.

[0078] In the above-described embodiment, the thickness x1 [μm] of the electrostatic electrode 24, the thickness y1 [μm] of the upper auxiliary electrode 26, the arrangement position (distance a1 [mm]) of the electrostatic electrode 24 in the upper plate 20, and the arrangement position (distance b1 [mm]) of the upper auxiliary electrode 26 in the upper plate 20 are preferably set such that the upper plate 20 becomes flat. In addition, the thickness x2 [μm] of the heating electrode 44, the thickness y2 [μm] of the lower auxiliary electrode 46, the arrangement position (distance a2 [mm]) of the heating electrode 44 in the lower plate 40, and the arrangement position (distance b2 [mm]) of the lower auxiliary electrode 46 in the lower plate 40 are preferably set such that the lower plate 40 becomes flat.

[0079] In the above-described embodiment, the electrostatic electrode 24 and the upper auxiliary electrode 26 preferably have the same material and thickness, and the distance a1 is preferably the same as the distance b1. In addition, the heating electrode 44 and the lower auxiliary electrode 46 preferably have the same material and thickness, and the distance a2 is preferably the same as the distance b2. In this way, the upper plate 20 and the lower plate 40 are likely to become flat.

[0080] In the above-described embodiment, the sealing band 22a and the circular protrusion 22b are not formed on the upper plate 20 prepared in step (a), but the sealing band 22a and the circular protrusion 22b may be formed on the upper plate 20 by sandblasting at this stage. In this case, step (c) is not required.

[0081] In the above-described embodiment, the diameter of the upper plate 20 is made the same as the diameter of the wafer W, but the diameter of the upper plate 20 may be made larger than the diameter of the wafer W, or the diameter of the upper plate 20 may be made smaller than the diameter of the wafer W.

[0082] In the above-described embodiment, the heating electrode 44 is provided so as to cover substantially the entire surface of the region when looking down on the lower plate 40, but the region when looking down on the lower plate 40 may be divided into a central circular region and an outer annular region, and a heating electrode may be provided for each region. In addition, the annular region may be further divided into a plurality of regions, and a heating electrode may be provided for each of the divided regions.

[0083] In the above-described embodiment, when looking down at the upper plate 20, the electrostatic electrode 24 and the upper auxiliary electrode 26 may have a coincident shape. Further, when looking down at the lower plate 40, the heating electrode 44 and the lower auxiliary electrode 46 may also have a coincident shape.

[0084] In the above-described embodiment, in order to prevent corrosion caused by the ambient atmosphere, a corrosion-resistant protective film may also be provided on the side surfaces of the first and second metal bonding layers 31 and 32, the portions of the intermediate plate 30 that are exposed to the outside, the portions of the intermediate plate 30 that are exposed to through-holes (such as thimble holes, air holes, etc.) that penetrate the semiconductor manufacturing apparatus member 10 in the vertical direction, and the like. As the corrosion-resistant protective film, for example, a ceramic spray coating film can be cited.

[0085] In the above-described embodiment, the heating electrode 44 is buried on the side closer to the upper surface in the lower plate 40, and the lower auxiliary electrode 46 is buried on the side closer to the lower surface, but it is not particularly limited thereto. For example, the lower auxiliary electrode may be buried on the side closer to the upper surface in the lower plate 40, and the heating electrode may be buried on the side closer to the lower surface. In this case, the intermediate plate 30 may also be connected to the RF power supply (i.e., the intermediate plate 30 is used as an RF electrode), and the lower auxiliary electrode may be grounded. Thus, the lower auxiliary electrode prevents the RF current from flowing from the intermediate plate 30 into the heating electrode, and therefore it is possible to avoid the RF current flowing into the heating electrode and having an adverse effect on the temperature control of the heating electrode.

[0086] [Examples]

[0087] Hereinafter, preferred embodiments of the present invention will be described. The present invention is not limited by any of the following examples. Experimental Examples 1 to 5 and 7 to 9 correspond to the embodiments of the present invention, and Experimental Example 6 corresponds to a comparative example. Their results are shown in Table 1.

[0088] [Table 1]

[0089]

[0090] [Experimental Example 1]

[0091] The semiconductor manufacturing apparatus member 10 of the above-described embodiment was manufactured by the above-described manufacturing method. The upper plate 20 and the lower plate 40 are made of Al2O3, the electrodes 24, 26, 44, and 46 are made of WC (tungsten carbide), and the intermediate plate 30 is made of SiSiCTiC. The coefficient of thermal expansion CTE (40 to 570 °C) of each material is shown in Table 1.

[0092] Regarding the upper plate 20, when fabricating the laminate 70 using the first to third MC sheets 71 to 73, the distance from the upper surface to the electrostatic electrode 24 is made the same as the distance from the lower surface to the upper auxiliary electrode 26. Therefore, in the alumina sintered body 76 obtained by firing the laminate 70, the distance from the upper surface to the electrostatic electrode 24 is also the same as the distance from the lower surface to the upper auxiliary electrode 26. Additionally, when machining the upper and lower surfaces of this alumina sintered body 76, the distance a1 from the upper surface to the electrostatic electrode 24 is made the same as the distance b1 from the lower surface to the upper auxiliary electrode 26. The specific dimensions and electrode shapes of the upper plate 20 are shown in Table 1. The obtained shape of the upper plate 20 is flat. Further, the outer diameter of the upper plate 20 is 300 mm, and the outer diameters of both the electrostatic electrode 24 and the upper auxiliary electrode 26 are 296 mm.

[0093] Regarding the lower plate 40, it is fabricated in the same manner as the upper plate 20. When fabricating the laminate using the first to third MC sheets, the distance from the upper surface to the heating electrode 44 is made the same as the distance from the lower surface to the lower auxiliary electrode 46. Therefore, in the alumina sintered body obtained by firing the laminate, the distance from the upper surface to the heating electrode 44 is also the same as the distance from the lower surface to the lower auxiliary electrode 46. Additionally, when machining the upper and lower surfaces of this alumina sintered body, the distance a2 from the upper surface to the heating electrode 44 is made the same as the distance b2 from the lower surface to the lower auxiliary electrode 46. The specific dimensions and electrode shapes of the lower plate 40 are shown in Table 1. The obtained shape of the lower plate 40 is flat. Further, the outer diameter of the lower plate 40 is 300 mm, and the outer diameters of both the heating electrode 44 and the lower auxiliary electrode 46 are 296 mm.

[0094] A first metal bonding material 301 is disposed between the upper plate 20 and the intermediate plate 30, and a second metal bonding material 302 is disposed between the lower plate 40 and the intermediate plate 30. The upper plate 20, the intermediate plate 30, and the lower plate 40 are bonded by TCB. As the first and second metal bonding materials 301, 302, an Al - Si - Mg - based bonding material is used.

[0095] Since the upper plate 20, the intermediate plate 30, and the lower plate 40 are all flat in shape, it is not easy to generate an uneven load during metal bonding, and bonding can be performed well. Additionally, since the upper plate 20 and the lower plate 40 do not warp, the generation of residual stress caused by the restoring force of warping can be prevented.

[0096] [Experimental Example 2]

[0097] Under the conditions shown in Experimental Example 2 of Table 1, the member 10 for a semiconductor manufacturing apparatus was manufactured in the same manner as in Experimental Example 1. Since the upper plate 20, the intermediate plate 30, and the lower plate 40 are all flat in shape, it is not easy to generate an eccentric load during metal bonding, and the bonding can be performed well. In addition, since the upper plate 20 and the lower plate 40 do not warp, it is possible to prevent the generation of residual stress caused by the restoring force of warping. Furthermore, for Experimental Example 2, when the shape of the upper auxiliary electrode 26 was changed to a concentric ring shape (refer to Figure 4 ), the same results as in Experimental Example 2 were also obtained.

[0098] [Experimental Example 3]

[0099] Under the conditions shown in Experimental Example 3 of Table 1, the member 10 for a semiconductor manufacturing apparatus was manufactured in the same manner as in Experimental Example 1. Since the upper plate 20, the intermediate plate 30, and the lower plate 40 are all flat in shape, it is not easy to generate an eccentric load during metal bonding, and the bonding can be performed well. In addition, since the upper plate 20 and the lower plate 40 do not warp, it is possible to prevent the generation of residual stress caused by the restoring force of warping. Furthermore, for Experimental Example 3, when the shape of the upper auxiliary electrode 26 was changed from a circular plate to a concentric ring shape (refer to Figure 4 ) and a spiral shape (refer to Figure 6 ), the same results as in Experimental Example 3 were also obtained.

[0100] [Experimental Example 4]

[0101] Under the conditions shown in Experimental Example 4 of Table 1, the member 10 for a semiconductor manufacturing apparatus was manufactured in the same manner as in Experimental Example 1. The upper plate 20 has a convex shape (the difference Δh1 between the maximum height and the minimum height is 0.1 mm), and the lower plate 40 also has a convex shape (the difference Δh2 between the maximum height and the minimum height is 0.1 mm). However, since Δh1 and Δh2 are within the allowable range (within 0.1 mm), it is not easy to generate an eccentric load during metal bonding, and the bonding can be performed well. In addition, since Δh1 and Δh2 are within the allowable range, it is possible to prevent the generation of residual stress caused by the restoring force of warping.

[0102] [Experimental Example 5]

[0103] Under the conditions shown in Experimental Example 5 of Table 1, the member 10 for a semiconductor manufacturing apparatus was manufactured in the same manner as in Experimental Example 1. Since the upper plate 20, the intermediate plate 30, and the lower plate 40 are all flat in shape, it is not easy to generate an eccentric load during metal bonding, and the bonding can be performed well. In addition, since the upper plate 20 and the lower plate 40 do not warp, it is possible to prevent the generation of residual stress caused by the restoring force of warping.

[0104] [Experimental Example 6]

[0105] Under the conditions shown in Experimental Example 6 of Table 1, the component 10 for a semiconductor manufacturing apparatus was manufactured in the same manner as in Experimental Example 1. Both the upper plate 20 and the lower plate 40 are concave in shape, and both Δh1 and Δh2 are 0.2 mm, that is, outside the allowable range. Therefore, an uneven load was generated during metal bonding, and the bonding could not be performed well. In addition, the generation of residual stress caused by the restoring force of warping could not be prevented.

[0106] [Experimental Example 7]

[0107] Under the conditions shown in Experimental Example 7 of Table 1, the component 10 for a semiconductor manufacturing apparatus was manufactured in the same manner as in Experimental Example 1. Both the upper plate 20 and the lower plate 40 are concave in shape, but both Δh1 and Δh2 are 0.1 mm, that is, within the allowable range (within 0.1 mm). Therefore, an uneven load is less likely to be generated during metal bonding, and the bonding can be performed well. In addition, since Δh1 and Δh2 are within the allowable range, the generation of residual stress caused by the restoring force of warping can be prevented.

[0108] [Experimental Example 8]

[0109] Under the conditions shown in Experimental Example 8 of Table 1, the component 10 for a semiconductor manufacturing apparatus was manufactured in the same manner as in Experimental Example 1. Since the upper plate 20, the intermediate plate 30, and the lower plate 40 are all flat in shape, an uneven load is less likely to be generated during metal bonding, and the bonding can be performed well. In addition, since the upper plate 20 and the lower plate 40 do not warp, the generation of residual stress caused by the restoring force of warping can be prevented.

[0110] [Experimental Example 9]

[0111] Under the conditions shown in Experimental Example 9 of Table 1, the component 10 for a semiconductor manufacturing apparatus was manufactured in the same manner as in Experimental Example 1. Since the upper plate 20, the intermediate plate 30, and the lower plate 40 are all flat in shape, an uneven load is less likely to be generated during metal bonding, and the bonding can be performed well. In addition, since the upper plate 20 and the lower plate 40 do not warp, the generation of residual stress caused by the restoring force of warping can be prevented.

Claims

1. A component for a semiconductor manufacturing apparatus, comprising: An upper plate made of ceramic, which has a wafer placement surface and incorporates parallel static electrodes and upper auxiliary electrodes; An intermediate plate, which is joined to the surface of the upper plate opposite to the wafer placement surface via a first metal bonding layer; and A lower plate, which is joined to the surface of the intermediate plate opposite to the surface joined to the upper plate via a second metal bonding layer and incorporates parallel heating electrodes and lower auxiliary electrodes, The diameter of the intermediate plate is larger than the diameters of the upper plate and the lower plate.

2. The component for a semiconductor manufacturing apparatus according to claim 1, wherein the upper auxiliary electrode is an electrode electrically connected to the static electrode via a through hole provided in the upper plate, or an electrode electrically connected to the intermediate plate, or an independent electrode that is neither electrically connected to the static electrode nor electrically connected to the intermediate plate.

3. The component for a semiconductor manufacturing apparatus according to claim 1 or 2, wherein the lower auxiliary electrode is an electrode electrically connected to the heating electrode via a through hole provided in the lower plate, or an independent electrode that is neither electrically connected to the heating electrode nor electrically connected to the intermediate plate.

4. The component for a semiconductor manufacturing apparatus according to claim 1 or 2, wherein the thickness of the static electrode, the thickness of the upper auxiliary electrode, the arrangement position of the static electrode in the upper plate, and the arrangement position of the upper auxiliary electrode in the upper plate are set such that the upper plate is flat, The thickness of the heating electrode, the thickness of the lower auxiliary electrode, the arrangement position of the heating electrode in the lower plate, and the arrangement position of the lower auxiliary electrode in the lower plate are set such that the lower plate is flat.

5. The component for a semiconductor manufacturing apparatus according to claim 1 or 2, wherein the materials and thicknesses of the static electrode and the upper auxiliary electrode are the same, and the distance from the wafer placement surface of the upper plate to the static electrode is the same as the distance from the surface opposite to the wafer placement surface to the upper auxiliary electrode, The materials and thicknesses of the heating electrode and the lower auxiliary electrode are the same, and the distance from the bonding surface of the lower plate to the heating electrode is the same as the distance from the surface opposite to the bonding surface to the lower auxiliary electrode.

6. The component for a semiconductor manufacturing apparatus according to claim 1 or 2, The outer diameter of the static electrode is the same as the outer diameter of the upper auxiliary electrode, The outer diameter of the heating electrode is the same as the outer diameter of the lower auxiliary electrode.

7. The member for a semiconductor manufacturing apparatus according to claim 1 or 2, wherein the intermediate plate is made of a composite material of metal and ceramic or made of metal, and the lower plate is made of the same ceramic as the upper plate.

8. A method for manufacturing a member for a semiconductor manufacturing apparatus, comprising: (a) A process for preparing an upper plate, a lower plate, and an intermediate plate, wherein the upper plate is made of ceramic, has a wafer placement surface, and internally has parallel static electrodes and upper auxiliary electrodes, the lower plate internally has parallel heating electrodes and lower auxiliary electrodes, and the diameter of the intermediate plate is larger than the diameters of the upper plate and the lower plate; and (b) A process of obtaining a bonded body by disposing a first metal bonding material between the upper surface of the intermediate plate and the surface of the upper plate on the side opposite to the wafer placement surface, and disposing a second metal bonding material between the lower surface of the intermediate plate and the upper surface of the lower plate, and after pressurized heating in this state, returning to room temperature.

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