Component for semiconductor manufacturing apparatus and method for manufacturing the same

Abstract

The present invention provides a semiconductor manufacturing apparatus member having a concave or convex wafer placement surface with high dimensional accuracy and a manufacturing method thereof. The semiconductor manufacturing apparatus member (10) includes: an upper ceramic plate (20) having a concave wafer placement surface (22) and having an electrostatic electrode (24) built therein; an intermediate plate (30) joined to a surface of the upper plate (20) opposite to the wafer placement surface (22) via a first metal bonding layer (31); and a lower plate (40) joined to a surface of the intermediate plate (30) opposite to the surface joined to the upper plate (20) via a second metal bonding layer (32). The coefficient of thermal expansion of the intermediate plate (30) is greater than the coefficients of thermal expansion of the upper plate (20) and the lower plate (40).

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, a member for a semiconductor manufacturing apparatus is known, which includes: a ceramic electrostatic chuck having a wafer mounting surface, and a support substrate in which the electrostatic chuck is metal-bonded to a concave surface having a shape that is recessed in the center compared to the periphery (for example, refer to Patent Document 1). In this member for a semiconductor manufacturing apparatus, the electrostatic chuck is bonded in a state deformed into the same shape as the concave surface of the support substrate. In addition, the absolute value of the difference in thermal expansion coefficient between the ceramic of the electrostatic chuck and the composite material constituting the support substrate is 0.2×10 -6 / K or less. According to such a member for a semiconductor manufacturing apparatus, it is considered that since the wafer mounting surface of the electrostatic chuck is a concave surface, the wafer can be stably held on the wafer mounting surface.

[0003] Prior Art Documents

[0004] Patent Documents

[0005] Patent Document 1: Japanese Patent No. 6741548 Summary of the Invention

[0006] Problems to be Solved by the Invention

[0007] However, in Patent Document 1, it is difficult to finish-machine the concave surface of the support substrate with high precision. Therefore, it is difficult to obtain a concave-shaped wafer mounting surface with high dimensional accuracy.

[0008] The present invention has been completed to solve such problems, and its main object is to provide a member for a semiconductor manufacturing apparatus having a concave-shaped or convex-shaped wafer mounting surface with high dimensional accuracy.

[0009] Means for Solving the Problems

[0010] The member for a semiconductor manufacturing apparatus of the present invention includes:

[0011] an upper plate made of ceramic, which has a concave-shaped or convex-shaped wafer mounting surface and has an electrostatic electrode built therein;

[0012] an intermediate plate, which is bonded to a surface of the upper plate opposite to the wafer mounting surface via a first metal bonding layer; and

[0013] a lower plate, which is bonded to a surface of the intermediate plate opposite to the surface to which the upper plate is bonded via a second metal bonding layer,

[0014] wherein the thermal expansion coefficient of the intermediate plate is greater than the thermal expansion coefficients of the upper plate and the lower plate.

[0015] In the member for a semiconductor manufacturing apparatus, the coefficient of thermal expansion of the intermediate plate is greater than those of the upper plate and the lower plate. Therefore, by utilizing the thermal expansion differences between the intermediate plate and the upper plate and between the intermediate plate and the lower plate, the wafer mounting surface can be made into a concave shape or a convex shape with high dimensional accuracy.

[0016] In the member for a semiconductor manufacturing apparatus of the present invention, the intermediate plate may be made of a composite material of metal and ceramic or metal, and the lower plate may be made of the same ceramic as the upper plate and have a different thickness from the upper plate. In this way, it is easy to make the coefficient of thermal expansion of the intermediate plate greater than those of the upper plate and the lower plate. In addition, although the upper plate and the lower plate are made of the same ceramic, due to the different thicknesses, it is easy to make the wafer mounting surface into a concave shape or a convex shape.

[0017] In this case, the wafer mounting surface may be concave, and the upper plate may be thinner than the lower plate. Alternatively, the wafer mounting surface may be convex, and the upper plate may be thicker than the lower plate.

[0018] Alternatively, a resistance heating element may be provided in at least one of the upper plate and the lower plate. In this way, the member for a semiconductor manufacturing apparatus can be used as an electrostatic chuck heater. A resistance heating element may also be provided in the lower plate, and the diameter of the region where the resistance heating element is wired may be equal to or greater than the diameter of the upper plate. In this way, since the resistance heating element can heat the entire surface of the wafer mounting surface of the upper plate, the heat uniformity of the wafer is improved.

[0019] The method for manufacturing the member for a semiconductor manufacturing apparatus of the present invention includes:

[0020] (a) A step of preparing a lower plate, a ceramic upper plate having a wafer mounting surface and having an electrostatic electrode provided therein, and an intermediate plate having a coefficient of thermal expansion greater than those of the upper plate and the lower plate; and

[0021] (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 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 performing pressure heating in this state and then returning to room temperature.

[0022] According to the method for manufacturing the member for a semiconductor manufacturing apparatus, by utilizing the thermal expansion differences between the intermediate plate and the upper plate and between the intermediate plate and the lower plate generated in step (b), the wafer mounting surface can be made into a concave shape or a convex shape with high precision.

[0023] In the method for manufacturing a component for a semiconductor manufacturing apparatus according to the present invention, in the step (a), when preparing the lower plate, the lower plate may be processed in advance so that the thickness of the lower plate becomes a predetermined target thickness. By making the thickness of the lower plate the target thickness before obtaining the bonded body in this way, the wafer mounting surface can be made into a concave shape or a convex shape with high precision.

[0024] In the method for manufacturing a component for a semiconductor manufacturing apparatus according to the present invention, in the step (b), after obtaining the bonded body, the lower plate may be processed so that the thickness of the lower plate becomes a predetermined target thickness different from the thickness of the upper plate. By making the thickness of the lower plate the target thickness after obtaining the bonded body in this way, the wafer mounting surface can be made into a concave shape or a convex shape with high precision.

[0025] In the method for manufacturing a component for a semiconductor manufacturing apparatus according to the present invention, in the step (b), after obtaining the bonded body, the thickness of the lower plate may be adjusted so that the shape of the upper plate becomes a predetermined concave shape or convex shape. In this way, the wafer mounting surface can be made into a concave shape or a convex shape with higher precision. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 is a cross-sectional view of the component 10 for a semiconductor manufacturing apparatus.

[0027] Figure 2 is a top view of the wafer mounting surface 22.

[0028] Figure 3 is an enlarged cross-sectional view of the wafer mounting surface 22.

[0029] Figure 4 is a cross-sectional view showing a state where the component 10 for a semiconductor manufacturing apparatus is mounted on the cooling device 50.

[0030] Figure 5 is a manufacturing process diagram of the component 10 for a semiconductor manufacturing apparatus.

[0031] Figure 6 is a cross-sectional view of the component 110 for a semiconductor manufacturing apparatus.

[0032] Figure 7 is an enlarged cross-sectional view of the wafer mounting surface 122.

[0033] Figure 8 is a cross-sectional view of the component 210 for a semiconductor manufacturing apparatus. DETAILED DESCRIPTION OF THE INVENTION

[0034] Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings. Figure 1It is a cross-sectional view of the component 10 for a semiconductor manufacturing apparatus (a cross-sectional view when cut by a vertical plane passing through the center of the component 10). Figure 2 It is a top view of the wafer placement surface 22. Figure 3 It is an enlarged cross-sectional view of the wafer placement surface 22.

[0035] 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.

[0036] The upper plate 20 is a disk-shaped plate made of ceramic (such as alumina, aluminum nitride) with the same diameter as the silicon wafer W on which plasma processing is performed, and an electrostatic electrode 24 and a resistance heating element 26 are built therein. Therefore, the upper plate 20 functions as an electrostatic chuck and also functions as a heater. The diameter of the upper plate 20 is not particularly limited, and for example, it can be set to 250 to 350 mm. The upper surface of the upper plate 20 is the wafer placement surface 22.

[0037] As Figure 3 shown, the wafer placement surface 22 has a concave shape (a shape in which the central part is recessed more than the outer peripheral part). The wafer W placed on this placement surface 22 uses a concave-shaped wafer. That is, the wafer placement surface 22 is formed in imitation of the concave-shaped wafer W. The depth of the most recessed part in the wafer placement surface 22 (the difference between the maximum height and the minimum height of the wafer placement surface 22, also called flatness) is preferably 1 to 500 μm, and more preferably 30 to 300 μm. As Figure 2 and Figure 3 shown, in the wafer placement surface 22, a sealing band 22a is formed along the outer edge, and a plurality of circular protrusions 22b are formed on the entire surface. The sealing band 22a and the circular protrusions 22b have the same height, and the height is, for example, several μm to several tens of μm.

[0038] The electrostatic electrode 24 is a circular surface electrode to which a DC voltage can be applied by an external power source via a power supply terminal (not shown). The part between the wafer placement surface 22 and the electrostatic electrode 24 in the upper plate 20 functions as a dielectric layer 28. Regarding the thickness of the dielectric layer 28, it 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 this electrostatic electrode 24, the wafer W placed on the wafer placement surface 22 is adsorbed and fixed to the wafer placement surface 22, and when the application of the DC voltage is released, the adsorption and fixation of the wafer on the wafer placement surface 22 are released. As Figure 3As shown, 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 S1 is generated 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-conducting gas (e.g., He gas) is supplied into this space S1 through a gas supply passage (not shown) that penetrates the member 10 for semiconductor manufacturing device in the vertical direction. The heat-conducting gas is used to efficiently perform heat exchange between the upper plate 20 and the wafer W. The resistive heating element 26 is patterned in one stroke so as to be wired over the entire surface of the upper plate 20, and generates heat when a voltage is applied to heat the wafer W. The region where the resistive heating element 26 is wired is circular in a top view. Both the electrostatic electrode 24 and the resistive heating element 26 are provided parallel to the wafer mounting surface 22. It should be noted that "parallel" is regarded as parallel not only in the case of complete parallelism, but also when it is not completely parallel as long as it is within the tolerance range.

[0039] The intermediate plate 30 is a disk-shaped plate, and its 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 of the upper plate 20 on the side opposite to the wafer mounting surface 22 via the first metal bonding layer 31. The coefficient of thermal expansion of the intermediate plate 30 is greater than the coefficients of thermal expansion of the upper plate 20 and the lower plate 40. Here, the coefficient of thermal expansion can also be, for example, the linear coefficient of thermal expansion at 40 to 570 °C. Examples of the material of the intermediate plate 30 include composite materials and metals. Examples of the composite material include ceramic-metal composite materials (also called metal matrix composites (MMC)). Examples of MMC include materials containing Si, SiC, and Ti (also called SiSiCTi), materials obtained by impregnating SiC porous bodies with Al and / or Si, etc. Examples of the metal include Ti, Mo, etc. Regarding the material of the intermediate plate 30, a material having a coefficient of thermal expansion greater than the coefficients of thermal expansion of the upper plate 20 and the lower plate 40 is selected.

[0040] 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. The lower plate 40 can be made of metal, MMC, or ceramic, and is preferably made of ceramic. In the present embodiment, the lower plate 40 is made of the same material as the ceramic of the upper plate 20, and the upper plate 20 is thinner than the lower plate 40. As a result, the wafer mounting surface 22 of the upper plate 20 becomes a concave shape. It should be noted that the intermediate plate 30 is preferably thicker than the upper plate 20 and the lower plate 40. For example, the thickness of the upper plate 20 can be set to 1 mm or more and 3 mm or less, the thickness of the lower plate 40 can be set to 6 mm or more and 10 mm or less, and the thickness of the intermediate plate 30 can be set to greater than 10 mm and 20 mm or less.

[0041] 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 porous SiC body or metal Mo. However, as long as it is a combination of materials that satisfies the relationship that the coefficient of thermal expansion of the intermediate plate 30 is larger than the coefficients of thermal expansion of the upper plate 20 and the lower plate 40, the combination is not particularly limited to this combination.

[0042] The first and second metal bonding layers 31 and 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 and 32 are not particularly limited, and are preferably 1 to 300 μm, more preferably 50 to 150 μm. In addition, 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 and 32 are formed by TCB (Thermalcompression bonding), for example. 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 in a state where they are heated to a temperature below the solidus temperature of the metal bonding material.

[0043] Next, a usage example of the member 10 for a semiconductor manufacturing apparatus will be described. Figure 4It is a cross-sectional view showing a case where a member 10 for a semiconductor manufacturing apparatus is mounted on a 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-shaped 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 disposing an annular sealing member 57 between the outer peripheral portion on the back surface of the intermediate plate 30 and the annular surface 56 and inserting the lower plate 40 into the circular groove 54, and then using a fastening ring 60. 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 fastening 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 fastening ring 60, and this step 62 can press the upper surface of the outer peripheral portion of the intermediate plate 30 from above. In addition, the fastening ring 60 has a longitudinal hole 64 through which a screw 71 can be inserted and a threaded hole 66 that can be threadedly engaged with a screw 72. The screw 71 is inserted from above into the longitudinal hole 64 and is threadedly engaged with a threaded hole 58 provided on the annular surface 56 of the cooling device 50. The screw 72 is inserted from below into a screw insertion hole 59 that penetrates the cooling device 50 in the vertical direction and is threadedly engaged with a threaded hole 66 provided on the back surface of the fastening ring 60. A plurality (for example, 8) of such screws 71 and 72 are provided at equal intervals in the circumferential direction of the fastening ring 60. Thereby, the space S2 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 S2. 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.

[0044] After installing the member 10 for a semiconductor manufacturing apparatus on the cooling device 50, the concave-shaped wafer W is placed on the wafer placement surface 22. Then, the inside of the vacuum chamber is depressurized by a vacuum pump to adjust to a predetermined vacuum degree, and a DC voltage is applied to the electrostatic electrode 24 to adsorb and fix the wafer W to the wafer placement surface 22. Since the wafer placement surface 22 is concave-shaped, the concave-shaped wafer W is in close contact with the sealing band 22a and the circular protrusion 22b of the wafer placement surface 22 without a gap, and the space S1 is sealed. A heat-conducting gas is supplied to this space S1. Since the heat-conducting gas is enclosed, heat conduction can be efficiently performed between the upper plate 20 and the wafer W. Next, a reaction gas atmosphere of a predetermined pressure (for example, several tens to several hundreds of Pa) is formed in the vacuum chamber, and in this state, plasma is generated. Then, the surface of the wafer W is etched using the generated plasma. A controller (not shown) controls the power supplied to the resistance heating element 26 so that the temperature of the wafer W becomes a predetermined target temperature.

[0045] Next, a manufacturing example of the member 10 for a semiconductor manufacturing apparatus will be described. Figure 5 It 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.

[0046] First, the upper plate 20, the intermediate plate 30, and the lower plate 40 are prepared (refer to Figure 5 (a)). This process is called process (a).

[0047] The upper plate 20 can be manufactured as follows. Here, a manufacturing example of the alumina upper plate 20 will be described. First, disk-shaped first and second green sheets made of alumina are prepared. The electrostatic electrode 24 is formed on the surface of the first green sheet, and the resistance heating element 26 is formed on the surface of the second green sheet. As a method for forming the electrostatic electrode 24 and the resistance heating element 26, for example, screen printing, PVD, CVD, plating, etc. can be used. Next, other alumina green sheets (third green sheets) are laminated on the surface of the first green sheet on which the electrostatic electrode 24 is formed, and the second green sheet is laminated thereon so that the resistance heating element 26 is in contact with the third green sheet to form a laminate. Alternatively, the first green sheet can be arranged in a mold with the electrostatic electrode 24 facing upward, and the granulated alumina particles are spread on the surface on which the electrostatic electrode 24 is formed to a predetermined thickness, and the second green sheet is laminated thereon so that the resistance heating element 26 is in contact with the layer of the alumina particles, and they are pressed together to form a laminate. Then, the laminate is fired by a hot pressing method to obtain an alumina sintered body in which the electrostatic electrode 24 and the resistance heating element 26 are embedded. By performing grinding or sandblasting on both surfaces of the obtained alumina sintered body to adjust the shape and thickness, a flat upper plate 20 is obtained (refer toFigure 5 (a)). At this time, the thickness of the dielectric layer 28 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 an alumina formed body produced by a casting method (e.g., die casting method) can be used instead of the green sheet made of alumina. Alternatively, an alumina sintered body can be used instead of the first and second green sheets, or an alumina sintered body can be used instead of the third green sheet. Regarding the specific manufacturing conditions of the upper plate 20, for example, the conditions described in Japanese Patent Laid-Open No. 2006-196864 can be referred to for setting.

[0048] The intermediate plate 30 can be manufactured in the following manner. Here, a manufacturing example of the SiSiCTi intermediate plate 30 will be described. First, a SiSiCTi disk member is produced. For example, a powder mixture is produced, which contains silicon carbide raw material particles with an average particle size of 10 μm or more and 25 μm or less and containing 39 to 51% by mass, and one or more raw materials selected in such a way as to contain 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. At this time, 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 formed into a disk-shaped formed body by uniaxial pressure forming, and the formed body is sintered by hot pressing at 1370 to 1460 °C in an inert atmosphere, thereby obtaining a SiSiCTi disk member. It should be noted that the stamping pressure during hot pressing is set to, for example, 50 to 300 kgf / cm 2 . Then, the obtained disk member is adjusted in shape and thickness by grinding or the like to obtain the intermediate plate 30 (see Figure 5 (a)). When the upper plate 20 is made of alumina, the linear thermal expansion coefficient of alumina at 40 to 570 °C is 7.7×10 -6 / K. Therefore, as the intermediate plate 30, a plate with a linear thermal expansion coefficient at 40 to 570 °C exceeding 7.7×10 -6 / K is produced. Regarding the specific manufacturing conditions of the intermediate plate 30, for example, the conditions described in Japanese Patent No. 5666748 can be referred to for setting.

[0049] The lower plate 40 can be manufactured in the following manner. Here, a manufacturing example of the alumina lower plate 40 will be described. First, a disk-shaped alumina formed body is produced, and the alumina formed body is fired to form an alumina sintered body. The shape and thickness are adjusted by performing grinding or sandblasting on both surfaces of the obtained alumina sintered body to obtain a flat lower plate 40 (see Figure 5(a)). In this embodiment, the thickness of the lower plate 40 is adjusted in advance to a predetermined target thickness (a thickness exceeding the thickness of the upper plate 20).

[0050] 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, an intermediate plate 30 is placed thereon, and then 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. The upper plate 20 is placed in such a manner that the surface opposite to the wafer placement surface 22 contacts the first 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 each metal bonding material 301, 302 interposed therebetween can be obtained. Next, the sandwich laminate is pressurized at a temperature below the solidus temperature of the first and second metal bonding materials 301, 302 (for example, at a temperature above the temperature obtained by subtracting 20°C from the solidus temperature and below 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 5 (b)), and then returned to room temperature. Thus, a bonded body 80 in which the first metal bonding material 301 becomes the first metal bonding layer 31 and the second metal bonding material 302 becomes the second metal bonding layer 32 is obtained (refer to Figure 5 (c)). This process is referred to as process (b). As the first and second metal bonding materials 301, 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, with a solidus temperature of about 560°C), in a vacuum atmosphere, while heating to a state of 540 - 560°C (for example, 550°C), the upper plate 20 is pressurized at a pressure of 0.5 - 2.0 kg / mm 2 (for example, 1.5 kg / mm 2 ) for several hours. The first and second metal bonding materials 301, 302 are preferably materials having a thickness of about 100 μm. Since the coefficient of thermal expansion of the intermediate plate 30 is larger than the coefficients of thermal expansion of the upper plate 20 and the lower plate 40, and the upper plate 20 is thinner than the lower plate 40, the wafer placement surface 22 of the upper plate 20 of the bonded body 80 becomes concave.

[0051] Next, a pattern mask is pasted on the wafer placement surface 22 of the upper plate 20 of the bonded body 80. The pattern mask has openings in the portions where the sealing band 22a and the circular protrusion 22b are formed, and sandblasting medium is sprayed to perform sandblasting (refer to Figure 5 (c)). The sealing band 22a and the circular protrusion 22b are formed on the wafer placement surface 22 by sandblasting. Then, the mask is removed to obtain the member 10 for a semiconductor manufacturing apparatus (refer toFigure 5 (d)). As needed, the bottom surface of the lower plate 40 can be processed to be flat, or the thickness of the lower plate 40 can be adjusted by grinding so that the concave shape of the wafer placement surface 22 becomes the target concave shape.

[0052] According to the component 10 for a semiconductor manufacturing apparatus described in detail above, since the coefficient of thermal expansion of the intermediate plate 30 is larger than that of the upper plate 20 and the lower plate 40, the wafer placement surface 22 can be made into a concave shape with high dimensional accuracy by utilizing the thermal expansion difference between the intermediate plate 30 and the upper plate 20 and the thermal expansion difference between the intermediate plate 30 and the lower plate 40.

[0053] In addition, the intermediate plate 30 is made of a composite material of metal and ceramic or metal, and the upper plate 20 and the lower plate 40 are made of the same ceramic. Therefore, it is easy to make the coefficient of thermal expansion of the intermediate plate 30 larger than that of the upper plate 20 and the lower plate 40. In addition, since the upper plate 20 is thinner than the lower plate 40, it is easy to make the wafer placement surface 22 into a concave shape.

[0054] Furthermore, an electrostatic electrode 24 and a resistance heating element 26 are built into the upper plate 20. Therefore, the component 10 for a semiconductor manufacturing apparatus can be used as an electrostatic chuck heater. In addition, the concave shape of the wafer placement surface 22 can also be adjusted by the electrostatic electrode 24 and the resistance heating element 26 built into the upper plate 20.

[0055] In addition, the manufacturing method of the component 10 for a semiconductor manufacturing apparatus includes the following steps: (a) a step of preparing a lower plate 40, a ceramic upper plate 20 having a wafer placement surface 22 and built-in with an electrostatic electrode 24, and an intermediate plate 30 having a coefficient of thermal expansion larger than that of the upper plate 20 and the lower plate 40; (b) a step of disposing a first metal bonding material 301 between the upper surface of the intermediate plate 30 and the surface of the upper plate 20 opposite to the wafer placement surface 22, and disposing a second metal bonding material 302 between the lower surface of the intermediate plate 30 and the upper surface of the lower plate 40, and after pressurizing and heating in this state and then returning to room temperature, obtaining a bonded body. In this way, the wafer placement surface 22 can be made into a concave shape with high precision by utilizing the thermal expansion difference between the intermediate plate 30 and the upper plate 20 and the thermal expansion difference between the intermediate plate 30 and the lower plate 40 generated in step (b).

[0056] Moreover, in step (a), when preparing the lower plate 40, it is processed in such a way that the thickness of the lower plate 40 becomes the target thickness. By setting the thickness of the lower plate 40 to the target thickness before obtaining the bonded body 80 in this way, the wafer placement surface 22 can be made into a concave shape with high precision.

[0057] It should be noted that, self - evidently, the present invention is not limited by any of the above - described embodiments. As long as it belongs to the technical scope of the present invention, it can of course be implemented in various ways.

[0058] For example, in the above - described embodiment, the thickness of the lower plate 40 is adjusted to the target thickness in step (a). However, the thickness of the lower plate 40 can also be formed thicker than the target thickness in step (a), and after obtaining the bonded body 80 in step (b), the lower plate 40 can be processed in such a way that the thickness of the lower plate 40 becomes the target thickness. By operating in this way, the wafer mounting surface 22 can also be made into a concave shape with high precision. Or, after obtaining the bonded body 80 in step (b), the thickness of the lower plate 40 can be adjusted so that the wafer mounting surface 22 becomes a predetermined concave shape. In this way, the wafer mounting surface 22 can be made into a concave shape with higher precision.

[0059] 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). However, the sealing band 22a and the circular protrusion 22b can also be formed on the upper plate 20 by sandblasting at this stage.

[0060] In the above - described embodiment, the wafer mounting surface 22 is made into a concave shape, the upper plate 20 and the lower plate 40 are made of the same ceramic, and the upper plate 20 is thinner than the lower plate 40. However, it is not particularly limited thereto. For example, it can also be like Figure 6 and Figure 7 the component 110 for a semiconductor manufacturing apparatus shown, in which the wafer mounting surface 122 of the upper plate 120 is made into a convex shape (a shape in which the central part protrudes more than the outer peripheral part), the upper plate 120 and the lower plate 140 are made of the same ceramic, and the upper plate 120 is thicker than the lower plate 140. It should be noted that in Figure 6 and Figure 7 the same reference numerals are given to the same components as those in the above - described embodiment. In this case, the wafer W placed on the wafer mounting surface 122 uses a convex - shaped wafer. That is, the wafer mounting surface 122 is formed in imitation of the convex - shaped wafer W. Therefore, the convex - shaped wafer W is in close contact with the sealing band 22a and the circular protrusion 22b of the wafer mounting surface 122 without gaps, and the space S1 is sealed. In the component 110 for a semiconductor manufacturing apparatus, for example, the thickness of the upper plate 120 can be set to be 3 mm or more and 5 mm or less, the thickness of the lower plate 140 can be set to be 1 mm or more and 3 mm or less, and the thickness of the intermediate plate 30 can be set to be greater than 10 mm and 20 mm or less.

[0061] Here, the wafer mounting surface 122 of the semiconductor manufacturing apparatus member 110 having a convex shape can be manufactured according to the manufacturing method of the above-described embodiment. Specifically, in step (a), when preparing the lower plate 140, the lower plate 40 is processed such that the thickness becomes a predetermined target thickness (a value thinner than the upper plate 120). By making the thickness of the lower plate 140 the target thickness before obtaining the bonded body in this way, the wafer mounting surface 122 can be made to have a convex shape with high precision. Alternatively, in step (b), after obtaining the bonded body, the lower plate 140 may be processed such that the thickness of the lower plate 140 becomes the target thickness (a value thinner than the upper plate 120). By operating in this way, the wafer mounting surface 122 can also be made to have a convex shape with high precision. Further, in step (b), after obtaining the bonded body, the thickness of the lower plate 140 may be adjusted so that the wafer mounting surface 122 has a predetermined convex shape. In this way, the wafer mounting surface 122 can be made to have a convex shape with even higher precision. Note that the lower surface of the lower plate 140 may be finally processed to be flat.

[0062] In the above-described embodiment, the resistance heating element 26 is embedded in the upper plate 20, but it may be, as in Figure 8 the semiconductor manufacturing apparatus member 210 shown, such that the resistance heating element 26 is not embedded in the upper plate 220 but the resistance heating element 226 is embedded in the lower plate 240. In this case, the diameter D2 of the region (circular region in plan view) in which the resistance heating element 226 is embedded is preferably equal to or larger than the diameter D1 of the upper plate 220. In this way, when heating the wafer W having the same diameter as the diameter D1 of the upper plate 20, heating can be performed uniformly.

[0063] 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 larger than the diameter of the wafer W, or the diameter of the upper plate 20 may be smaller than the diameter of the wafer W.

[0064] [Examples]

[0065] Hereinafter, preferred embodiments of the present invention will be described. The present invention is not limited by any of the following embodiments. Experimental Examples 1, 3 to 6, 8 to 11, and 13 to 15 correspond to embodiments of the present invention, and Experimental Examples 2, 7, and 12 correspond to comparative examples. Their results are shown in Table 1.

[0066] [Table 1]

[0067]

[0068] [Experimental Example 1]

[0069] Prepare Al 2 O 3The upper plate 20 and the lower plate 40 made of Al, and the intermediate plate 30 made of SiSiCTi are used to manufacture the component 10 for a semiconductor manufacturing apparatus of the above-described embodiment by the above manufacturing method. Al 2 O 3 has a linear thermal expansion coefficient of 7.7×10 -6 / K in the range of 40 to 570 °C, and SiSiCTi has a linear thermal expansion coefficient of 7.8×10 -6 / K in the range of 40 to 570 °C. As the first and second metal bonding materials 301 and 302, an Al-Si-Mg-based bonding material is used, and the upper plate 20, the intermediate plate 30, and the lower plate 40 are bonded by TCB. Before bonding, the thickness of the upper plate 20 is adjusted to 2 mm. It should be noted that the thickness of the dielectric layer 28 and the distance from the wafer mounting surface 22 to the resistance heating element 26 are set to the same values in all the experimental examples. The thicknesses of the intermediate plate 30 and the lower plate 40 are adjusted to 15 mm and 8 mm, respectively, before bonding. As a result, the obtained component 10 for a semiconductor manufacturing apparatus has a concave-shaped wafer mounting surface 22, and the flatness (the difference between the maximum height and the minimum height of the wafer mounting surface 22) of the wafer mounting surface 22 is 0.06 mm.

[0070] [Experimental Example 2]

[0071] In Experimental Example 1, the thicknesses of the upper plate and the lower plate before bonding were both changed to 4 mm, and otherwise, the operation was the same as in Experimental Example 1 to manufacture a component for a semiconductor manufacturing apparatus. As a result, the obtained component for a semiconductor manufacturing apparatus has a flat wafer mounting surface, and its flatness is 0.00 mm.

[0072] [Experimental Example 3]

[0073] In Experimental Example 1, the thickness of the upper plate before bonding was changed to 4 mm, and the thickness of the lower plate was changed to 2 mm, and otherwise, the operation was the same as in Experimental Example 1 to manufacture a component for a semiconductor manufacturing apparatus. As a result, the obtained component for a semiconductor manufacturing apparatus has a convex-shaped wafer mounting surface, and its flatness is 0.03 mm.

[0074] [Experimental Example 4]

[0075] In Experimental Example 1, the thickness of the lower plate before bonding was changed to 10 mm, and after bonding, the thickness of the lower plate was ground to 8 mm, and otherwise, the operation was the same as in Experimental Example 1 to manufacture a component for a semiconductor manufacturing apparatus. As a result, the obtained component for a semiconductor manufacturing apparatus has a concave-shaped wafer mounting surface, and its flatness is 0.06 mm.

[0076] [Experimental Example 5]

[0077] In Experimental Example 3, the thickness of the lower plate before bonding was changed to 4 mm, and after bonding, the bottom surface of the lower plate was ground so that the thickness of the lower plate became 2 mm. Otherwise, the operation was the same as in Experimental Example 3 to manufacture a component for a semiconductor manufacturing apparatus. As a result, the obtained component for a semiconductor manufacturing apparatus had a convex-shaped wafer placement surface with a flatness of 0.03 mm.

[0078] [Experimental Example 6]

[0079] In Experimental Example 1, the intermediate plate was changed to be made of metal Ti. Otherwise, the operation was the same as in Experimental Example 1 to manufacture a component for a semiconductor manufacturing apparatus. The linear thermal expansion coefficient of metal Ti at 40 to 570 °C was 11.1×10 -6 / K. The obtained component for a semiconductor manufacturing apparatus had a concave-shaped wafer placement surface with a flatness of 0.30 mm.

[0080] [Experimental Example 7]

[0081] In Experimental Example 2, the intermediate plate was changed to be made of metal Ti. Otherwise, the operation was the same as in Experimental Example 2 to manufacture a component for a semiconductor manufacturing apparatus. As a result, the obtained component for a semiconductor manufacturing apparatus had a flat wafer placement surface with a flatness of 0.00 mm.

[0082] [Experimental Example 8]

[0083] In Experimental Example 3, the intermediate plate was changed to be made of metal Ti. Otherwise, the operation was the same as in Experimental Example 3 to manufacture a component for a semiconductor manufacturing apparatus. As a result, the obtained component for a semiconductor manufacturing apparatus had a convex-shaped wafer placement surface with a flatness of 0.15 mm.

[0084] [Experimental Example 9]

[0085] In Experimental Example 4, the intermediate plate was changed to be made of metal Ti. Otherwise, the operation was the same as in Experimental Example 4 to manufacture a component for a semiconductor manufacturing apparatus. As a result, the obtained component for a semiconductor manufacturing apparatus had a concave-shaped wafer placement surface with a flatness of 0.30 mm.

[0086] [Experimental Example 10]

[0087] In Experimental Example 5, the intermediate plate was changed to be made of metal Ti. Otherwise, the operation was the same as in Experimental Example 5 to manufacture a component for a semiconductor manufacturing apparatus. As a result, the obtained component for a semiconductor manufacturing apparatus had a convex-shaped wafer placement surface with a flatness of 0.15 mm.

[0088] [Experimental Example 11]

[0089] In Experimental Example 1, the upper plate and the lower plate were made of AlN, and the middle plate was changed to be made of metal Mo. Otherwise, the operation was the same as in Experimental Example 1 to manufacture a component for a semiconductor manufacturing apparatus. The linear thermal expansion coefficient of AlN at 40 to 570 °C is 5.9×10 -6 / K, and the linear thermal expansion coefficient of metal Mo at 40 to 570 °C is 6.1×10 -6 / K. The obtained component for a semiconductor manufacturing apparatus has a concave-shaped wafer mounting surface with a flatness of 0.18 mm.

[0090] [Experimental Example 12]

[0091] In Experimental Example 2, the upper plate and the lower plate were made of AlN, and the middle plate was changed to be made of metal Mo. Otherwise, the operation was the same as in Experimental Example 2 to manufacture a component for a semiconductor manufacturing apparatus. As a result, the obtained component for a semiconductor manufacturing apparatus has a flat wafer mounting surface with a flatness of 0.00 mm.

[0092] [Experimental Example 13]

[0093] In Experimental Example 3, the upper plate and the lower plate were made of AlN, and the middle plate was changed to be made of metal Mo. Otherwise, the operation was the same as in Experimental Example 3 to manufacture a component for a semiconductor manufacturing apparatus. As a result, the obtained component for a semiconductor manufacturing apparatus has a convex-shaped wafer mounting surface with a flatness of 0.09 mm.

[0094] [Experimental Example 14]

[0095] In Experimental Example 4, the upper plate and the lower plate were made of AlN, and the middle plate was changed to be made of metal Mo. Otherwise, the operation was the same as in Experimental Example 4 to manufacture a component for a semiconductor manufacturing apparatus. As a result, the obtained component for a semiconductor manufacturing apparatus has a concave-shaped wafer mounting surface with a flatness of 0.18 mm.

[0096] [Experimental Example 15]

[0097] In Experimental Example 5, the upper plate and the lower plate were made of AlN, and the middle plate was changed to be made of metal Mo. Otherwise, the operation was the same as in Experimental Example 5 to manufacture a component for a semiconductor manufacturing apparatus. As a result, the obtained component for a semiconductor manufacturing apparatus has a convex-shaped wafer mounting surface with a flatness of 0.09 mm.

[0098] Symbol Explanation

[0099] 10, 110, 210: Components for semiconductor manufacturing equipment, 20, 120, 220: Upper plates, 22, 122: Wafer placement surfaces, 22a: Sealing tape, 22b: Circular protrusions, 24: Electrostatic electrodes, 26, 226: Resistance heating elements, 28: Dielectric layers, 30: Intermediate plates, 31: First metal bonding layer, 32: Second metal bonding layer, 40, 140, 240: Lower plates, 50: Cooling device, 52: Refrigerant passage, 54: Circular groove, 56: Annular surface, 57: Sealing member, 58: Threaded hole, 59: Screw insertion hole, 60: Fastening ring, 62: Step, 64: Longitudinal hole, 66: Threaded hole, 71, 72: Screws, 80: Bonded body, 301: First metal bonding material, 302: Second metal bonding material, W: Wafer, S1, S2: Spaces.

Claims

1. A component for a semiconductor manufacturing apparatus, comprising: An upper plate made of ceramic, which has a concave or convex wafer mounting surface and has an electrostatic electrode built therein; An intermediate plate, which is joined to the surface of the upper plate on the side opposite to the wafer mounting surface via a first metal bonding layer; and A lower plate, which is joined to the surface of the intermediate plate on the side opposite to the surface joined to the upper plate via a second metal bonding layer, The coefficient of thermal expansion of the intermediate plate is greater than that of the upper plate and the lower plate, A resistance heating element is built in the lower plate, The diameter of the area where the resistance heating element is wired is equal to or greater than the diameter of the upper plate.

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

3. The component for a semiconductor manufacturing apparatus according to claim 2, wherein the wafer mounting surface is concave, The upper plate is thinner than the lower plate.

4. The component for a semiconductor manufacturing apparatus according to claim 2, wherein the wafer mounting surface is convex, The upper plate is thicker than the lower plate.

5. The component for a semiconductor manufacturing apparatus according to any one of claims 1 to 4, wherein a resistance heating element is built in at least one of the upper plate and the lower plate.

6. A method for manufacturing a component for a semiconductor manufacturing apparatus, Comprising: (a) A step of preparing a lower plate, an upper plate made of ceramic having a wafer mounting surface and having an electrostatic electrode built therein, and an intermediate plate having a coefficient of thermal expansion greater than that of the upper plate and the lower plate; And (b) A step of obtaining a joined 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 performing pressure heating in this state and then returning to room temperature, A resistance heating element is built in the lower plate, The diameter of the area where the resistance heating element is wired is equal to or greater than the diameter of the upper plate.

7. The method for manufacturing a component for a semiconductor manufacturing apparatus according to claim 6, wherein in the step (a), when preparing the lower plate, the lower plate is processed in advance so that its thickness becomes a predetermined target thickness.

8. The method for manufacturing a component for a semiconductor manufacturing apparatus according to claim 6 or 7, wherein in the step (b), after obtaining the joined body, the lower plate is processed so that its thickness becomes a predetermined target thickness different from the thickness of the upper plate.

9. The method for manufacturing a component for a semiconductor manufacturing apparatus according to claim 6 or 7, wherein in the step (b), after obtaining the joined body, the thickness of the lower plate is adjusted so that the shape of the upper plate becomes a predetermined concave or convex shape.

Images