WAFER SUPPORT DEVICE AND SiC EPITAXIAL GROWTH DEVICE

Abstract

To provide a wafer support device capable of inhibiting damage during regeneration of a wafer guide.SOLUTION: A wafer support device includes a supporting base, a wafer guide part, a first chamfer part, and a second chamfer part. The supporting base has a support surface for supporting a wafer. The wafer guide part has an annular shape which encloses a periphery of the wafer supported by the support surface, centered on a center axis extending in a normal direction of the support surface. The first chamfer part connects an inner peripheral surface with an upper surface in the wafer guide part and extends from the inner peripheral surface in a direction gradually going upward toward the outer periphery side. The second chamfer part connects an outer peripheral surface with the upper surface in the wafer guide part and extends from the outer peripheral surface in a direction going upward toward the inner periphery side.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] SUMMARY OF THE DISCLOSURE Embodiments of the present invention relate to a wafer support apparatus and a SiC epitaxial growth apparatus. [Background technology]

[0002] In a wafer support device in a SiC epitaxial growth apparatus, a wafer guide is disposed around a wafer supported on a support surface. Reaction products are deposited on the wafer guide during the SiC epitaxial growth process. To facilitate the SiC epitaxial growth process, the deposited reaction products are removed by polishing or the like to regenerate the wafer guide. There is a possibility that the wafer guide will be damaged if removal processing is performed on the intersection between the top surface and the peripheral surface of the wafer guide, where the reaction products are likely to deposit. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent Publication No. 2022-102018 Summary of the Invention [Problem to be solved by the invention]

[0004] An object of the present invention is to provide a wafer support device and a SiC epitaxial growth apparatus capable of suppressing damage to a wafer guide during regeneration. [Means for solving the problem]

[0005] The wafer support device of the embodiment has a support table, a wafer guide portion, a first chamfered portion, and a second chamfered portion. The support table has a support surface that supports a wafer. The wafer guide portion is annular in shape surrounding the periphery of the wafer supported on the support surface, with a central axis extending in a normal direction to the support surface as its center. The first chamfered portion connects the inner peripheral surface and the top surface of the wafer guide portion, and extends in an upward direction from the inner peripheral surface toward the outer peripheral side. The second chamfered portion connects the outer peripheral surface and the top surface of the wafer guide portion, and extends in an upward direction from the outer peripheral surface toward the inner peripheral side. [Brief description of the drawings]

[0006] [Figure 1] FIG. 1 is a cross-sectional view showing a SiC epitaxial growth apparatus according to an embodiment. [Diagram 2] FIG. 2 is a cross-sectional view showing the wafer supporting device according to the embodiment. [Diagram 3] FIG. 3 is a partially enlarged view of FIG. 2. [Figure 4] FIG. 2 is a partial cross-sectional view showing the wafer support device after a SiC epitaxial growth process. [Diagram 5] FIG. 2 is a partial cross-sectional view showing the wafer support device after a SiC epitaxial growth process. [Figure 6] FIG. 2 is a diagram showing the in-plane distribution of a SiC epitaxial film. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0007] Hereinafter, the wafer support device and the SiC epitaxial growth device of the embodiment will be described with reference to the drawings. In the following description, components having the same or similar functions are given the same reference numerals. In addition, duplicated descriptions of those components may be omitted.

[0008] The configuration of the SiC epitaxial growth apparatus will be described below. FIG. 1 is a cross-sectional view of a SiC epitaxial growth apparatus 1 having a wafer support device 10 according to an embodiment.

[0009] In the following description, the side into which the supplied raw material gas flows is referred to as the upper side, and the side from which it flows out is referred to as the lower side. In the following description, the direction along the central axis J is simply referred to as the "axial direction." Furthermore, the radial direction centered on the central axis J may be simply referred to as the "radial direction." Furthermore, the circumferential direction centered on the central axis J may be simply referred to as the "circumferential direction."

[0010] 1, a SiC epitaxial growth apparatus 1 grows an epitaxial film that becomes an active region on a wafer W made of silicon carbide (SiC) by chemical vapor deposition (thermal CVD) or the like. The SiC epitaxial growth apparatus 1 includes a chamber 2, a reactor member 3, an upper heater 4, a lower heater 5, a rotating cylinder 6, a partition cylinder 7, and a wafer support device 10.

[0011] The chamber 2 is formed of a metal material such as stainless steel (SUS). The chamber 2 accommodates therein a reactor member 3, an upper heater 4, a lower heater 5, a rotating cylinder 6, a partition cylinder 7, and a wafer support device 10. The chamber 2 has an inlet 2A, an exhaust port 2B, and an insertion port 2C. The inlet 2A, the exhaust port 2B, and the insertion port 2C are provided so as to penetrate a bottom wall 2D of the chamber 2 in the axial direction.

[0012] The inlet 2A is formed to open at the upper end of the chamber 2. The inlet 2A is a portion through which the gases to be used, including the source gas G, supplied from above along the central axis J, are introduced into the chamber 2. The exhaust port 2B is a portion through which the gases to be used, including the source gas G, used in the SiC epitaxial growth process, are exhausted.

[0013] The source gas G reacts on the wafer W to form an epitaxial film. The source gas G is, for example, a Si-based gas and a C-based gas. The Si-based gas is, for example, silane (SiH4), dichlorosilane (SiH2Cl2), trichlorosilane (SiHCl3), and tetrachlorosilane (SiCl4). The C-based gas is, for example, propane (C3H8). The source gas G in the embodiment is, for example, SiH4+C3H8 (flow rate: tens to hundreds of sccm).

[0014] Other gases used besides the raw material gas G include impurity gas, carrier gas, and other gases. Examples of impurity gases include N2 (N-type impurity) and TMA (P-type impurity) (flow rate: several to several hundred sccm). Examples of carrier gases include H2 (during growth) and Ar (during transportation) (flow rate: 100 to 200 slm). Other gases include HCl (particle suppression during growth, high-speed growth) (flow rate: several tens of sccm to several hundred slm).

[0015] The reactor member 3 constitutes a furnace. The reactor member 3 is formed of graphite, for example. The reactor member 3 may have an inner surface coated with SiC or TaC to prevent dust generation. The reactor member 3 has a first cylindrical portion 3A, a tapered portion 3B, and a second cylindrical portion 3C.

[0016] The first cylindrical portion 3A is located at the upper side of the reactor member 3. The first cylindrical portion 3A opens below the inlet 2A of the chamber 2. A gas containing a source gas G introduced from the inlet 2A is introduced into the internal space of the reactor member 3. The internal space of the reactor member 3 is a film formation space K.

[0017] The tapered portion 3B extends in a radially outward direction from the lower end of the first cylindrical portion 3A toward the lower side. The second cylindrical portion 3C extends downward from the lower end of the tapered portion 3B. The radial position of the second cylindrical portion 3C is radially outward from the exhaust port 2B of the chamber 2. The tapered portion 3B is disposed in a range including the axial position of the first surface Wa facing the upper side of the wafer W in the vertical direction. Therefore, the gas containing the source gas G introduced from the inlet 2A into the film formation space K flows radially outward along the first surface Wa after reaching the wafer W. The gas containing the source gas G that flows radially outward from the wafer W is guided by the tapered portion 3B and the second cylindrical portion 3C and discharged from the exhaust port 2B of the chamber 2.

[0018] The upper heater 4 circumferentially surrounds the outer periphery of the first cylindrical portion 3A of the reactor member 3. The upper heater 4 extends in the axial direction along the first cylindrical portion 3A. The lower heater 5 is disposed below the wafer support device 10 and spaced apart from the wafer support device 10. The lower heater 5 is, for example, annular and extending in the circumferential direction. The wafer W is heated to, for example, a temperature range of 1500 to 1650° C. by the heating of the upper heater 4 and the lower heater 5. Known heaters can be used for the upper heater 4 and the lower heater 5.

[0019] The rotating shell 6 is rotatable in the circumferential direction. The rotating shell 6 has a first rotating shell 6A and a second rotating shell 6B. The first rotating shell 6A is provided above the second rotating shell 6B. The first rotating shell 6A is disposed above the bottom wall 2D of the chamber 2. A lower heater 5 is disposed inside the first rotating shell 6A. The diameter of the first rotating shell 6A is larger than the diameter of the second rotating shell 6B. The second rotating shell 6B extends downward from the first rotating shell 6A. The second rotating shell 6B is inserted into the insertion opening 2C.

[0020] The partition cylinder 7 is fixed to the bottom wall 2D of the chamber 2. The partition cylinder 7 extends upward along the axial direction. The partition cylinder 7 is disposed radially inward from the second cylindrical portion 3C and radially outward from the first rotating cylinder 6A.

[0021] The configuration of the wafer supporting device 10 will now be described. Fig. 2 is a cross-sectional view showing the wafer support device 10 according to the embodiment, and Fig. 3 is a partially enlarged view of Fig. 2. As shown in FIGS. 2 and 3, the wafer support device 10 includes a support table 11, a wafer guide portion 12, a first chamfering portion 13, a second chamfering portion 14, and a lifting portion 15. The lifting portion 15 lifts and lowers the wafer.

[0022] The support base 11 is disk-shaped and centered on the central axis J. The support base 11 is fixed to the first rotating cylinder 6A of the rotating cylinder 6. The support base 11 rotates in the circumferential direction by the rotation of the rotating cylinder 6. The support base 11 is a susceptor. The support base 11 has a support surface 11A and a through hole 11B. The support surface 11A supports the wafer W from below, radially outside the through hole 11B. The through hole 11B passes through the support base 11 in the axial direction, centered on the central axis J.

[0023] The support base 11 is formed of graphite, for example, and may be coated with SiC or TaC to prevent dust generation.

[0024] The wafer guide portion 12 is disposed by being joined from above to the peripheral portion of the support base 11. Although not shown in the drawings, a convex portion that protrudes from one of the support base 11 and the wafer guide portion 12 toward the other is provided at the joint between the support base 11 and the wafer guide portion 12. A concave portion into which the convex portion fits is provided on the other of the support base 11 and the wafer guide portion 12. By fitting the convex portion into the concave portion at the joint, the wafer guide portion 12 is fixed to the support base 11 in the radial direction.

[0025] The wafer guide portion 12 is annular in shape, centered on a central axis J extending in the normal direction of the support surface 11A, and surrounding the periphery of the wafer W supported on the support surface 11A. In a cross section including the central axis J, the wafer guide portion 12 has a rectangular cross section in which an intersection between the top surface 12a and the inner peripheral surface 12b is cut out by a first chamfered portion 13. In a cross section including the central axis J, the wafer guide portion 12 has a rectangular cross section in which an intersection between the top surface 12a and the outer peripheral surface 12c is cut out by a second chamfered portion 14.

[0026] That is, the first chamfered portion 13 connects the inner peripheral surface 12b and the upper surface 12a of the wafer guide portion 12, and extends in an upward direction from the inner peripheral surface 12b toward the outer peripheral side. The first chamfered portion 13 includes a first inclined surface 13a that inclines upward from the inner peripheral surface 12b toward the outer peripheral side in a cross section including the central axis J.

[0027] The second chamfered portion 14 connects the outer peripheral surface 12c and the upper surface 12a of the wafer guide portion 12, and extends in a direction from the outer peripheral surface 12c toward the inner peripheral side toward the upper side. The second chamfered portion 14 has a second inclined surface 14a that inclines upward from the outer peripheral surface 12c toward the inner peripheral side in a cross section including the central axis J. In other words, the first chamfered portion 13 and the second chamfered portion 14 are chamfers that extend linearly at an angle θ with respect to the upper surface 12a.

[0028] The first chamfered portion 13 may be an r-chamfer that curves in an arc shape from the inner circumferential surface 12b toward the outer circumferential surface and extends upward. The second chamfered portion 14 may be an r-chamfer that curves in an arc shape from the outer circumferential surface 12c toward the inner circumferential surface and extends upward.

[0029] As an example, at least the surface of the wafer guide portion 12 is made of poly-SiC. The wafer guide portion 12 may be configured to be entirely made of poly-SiC, or may be configured to be made of graphite with a SiC coating on the surface. However, when the wafer W rotates via the support stand 11 during the epitaxial growth process, the wafer W may move due to centrifugal force and collide with the wafer guide portion 12, resulting in peeling off of the SiC coating. In addition, the wafer guide portion 12 is unsuitable for regeneration by polishing, as described below. For these reasons, it is preferable that the wafer guide portion 12 be made entirely of poly-SiC.

[0030] The lifting / lowering unit 15 can move up and down in the axial direction. The lifting / lowering unit 15 is axially shaped and extends in the axial direction around the central axis J. The lifting / lowering unit 15 has a cylindrical holding unit 15A at its upper end. The diameter of the holding unit 15A is smaller than the diameter of the through hole 11B in the support base 11. The holding unit 15A is disposed below the wafer W when the lifting / lowering unit 15 is in the lowered position. In other words, the lowered position of the lifting / lowering unit 15 is a position where the holding unit 15A is below the wafer W. The holding unit 15A is separated from the wafer W when the lifting / lowering unit 15 is in the lowered position, but may be in contact with the wafer W when the wafer W is not rotating. When the lifting / lowering unit 15 is in the upper position to remove the wafer W from the wafer support device 10, the holding unit 15A moves the wafer W above the support surface 11A while holding the lower surface of the wafer W.

[0031] In the SiC epitaxial growth apparatus 1 having the above-described configuration, gas containing source gas G introduced into the film formation space K of the reactor member 3 heated to a high temperature (e.g., 1500 to 1650°C) by the upper heater 4 and the lower heater 5 flows radially outward from the center of the wafer W along the first surface Wa, as shown by the dashed line in Figure 2.

[0032] Fig. 4 is a partial cross-sectional view showing the wafer support device 10 after the SiC epitaxial growth process. By maintaining the supply of gas containing source gas G for a certain period of time while rotating the wafer W via the support table 11, an SiC epitaxial film Wb is formed on the first surface Wa of the wafer W as shown in Fig. 4. In addition, a deposit DP, which is a reaction product, accumulates on the wafer guide portion 12.

[0033] In the process of supplying the film forming material and attaching and depositing it on the wafer W, the material that reaches the wafer guide portion 12 moves, aggregates, and deposits due to the migration effect. At this time, if an inflection point exists in the wafer guide portion 12, it is considered that the movement slows down and the material becomes thick by being trapped. Therefore, in the wafer guide portion 12 having the first chamfered portion 13 and the second chamfered portion 14, the deposit DP at the intersection of the upper surface 12a and the first inclined surface 13a, which are the inflection points, and the deposit DP at the intersection of the upper surface 12a and the second inclined surface 14a grow and accumulate to the thickest.

[0034] FIG. 5 is a partial cross-sectional view showing the wafer supporting device 10 after the SiC epitaxial growth process when a wafer guide portion 12N that does not include the first chamfered portion 13 and the second chamfered portion 14 is used.

[0035] As shown in Fig. 5, in the wafer guide portion 12N that does not have the first chamfered portion 13 and the second chamfered portion 14, the deposit DP grows and accumulates thickest at the intersection of the upper surface 12a and the inner peripheral surface 12b, which are the inflection points, and at the intersection of the upper surface 12a and the outer peripheral surface 12c. The deposit DP in the wafer guide portion 12N protrudes toward the central axis J from the inner peripheral surface 12b and protrudes radially outward from the outer peripheral surface 12c. Even if a light chamfer is applied with a chamfering amount of about 0.1 to 0.2 mm, the chamfering amount is insufficient, and the deposit DP protrudes in the radial direction.

[0036] In this case, when the wafer W is raised by the lifting unit 15 in order to remove the wafer W from the wafer support device 10, the deposit DP protruding toward the central axis J may come into contact with the end of the wafer W. In addition, the deposit DP protruding radially outward beyond the outer circumferential surface 12c may come into contact with another member of the partition cylinder 7 and scatter or generate dust, which may cause particles. Since the wafer guide unit 12N is expensive, when the accumulation of the deposit DP becomes large, the wafer guide unit 12 is regenerated by removing the deposit DP by, for example, polishing or grinding the inner circumferential surface 12b and the outer circumferential surface 12c.

[0037] At this time, since the intersections of upper surface 12a and inner surface 12b, which are inflection points, and the intersections of upper surface 12a and outer surface 12c, are both right angles and have edge shapes, there is a possibility that defects such as cracks may occur in wafer guide portion 12N.

[0038] In contrast, in the wafer guide section 12 in the wafer support device 10 of the embodiment, the first chamfered portion 13 and the second chamfered portion 14 are provided, so that the intersection angle between the inner peripheral surface 12b and the first inclined surface 13a, the intersection angle between the first inclined surface 13a and the upper surface 12a, the intersection angle between the upper surface 12a and the second inclined surface 14a, and the intersection angle between the second inclined surface 14a and the outer peripheral surface 12c are all obtuse angles. Therefore, compared to the wafer guide section 12N in which the intersection portion serving as the inflection point is a right angle and stress is likely to concentrate, the wafer guide section 12 has an obtuse angle at the intersection portion serving as the inflection point, which alleviates stress concentration, and can suppress the occurrence of cracks in the wafer guide section 12. The wafer guide section 12 in the wafer support device 10 of the embodiment can be regenerated while suppressing the occurrence of cracks on both the inner peripheral surface 12b and the outer peripheral surface 12c.

[0039] As shown in FIG. 3, the thickness H1 of the wafer guide portion 12 in the direction along the central axis J is preferably 1.5 mm or more and 2.0 mm or less. If the thickness H1 of the wafer guide portion 12 is less than 1.5 mm, the wafer guide portion 12 may warp if the deposits DP adhere to the upper surface 12a, and may be prone to cracking during remanufacturing. If the thickness H1 of the wafer guide portion 12 exceeds 2.0 mm, the wafer guide portion 12 located above the first surface Wa of the wafer W may become a barrier and inhibit the flow of the source gas G radially outward along the first surface Wa of the wafer W.

[0040] 6 is a diagram showing the in-plane distribution of the SiC epitaxial film (epi-film) Wb when the wafer guide portion 12 acts as a barrier. As shown in FIG. 6, the flow of the source gas G is impeded on the radially outer side, causing turbulence, which may result in a thinner film thickness of the SiC epitaxial film Wb at the peripheral portion of the wafer W, resulting in a lower in-plane distribution. In addition, considering the thickness T1 (e.g., 300 to 600 μm) of a 6-inch or 8-inch wafer W, the wafer guide portion 12 may become thicker than necessary, resulting in increased costs.

[0041] By setting the thickness H1 of the wafer guide portion 12 to 1.5 mm or more and 2.0 mm or less, it is possible to suppress an increase in cost while reducing warpage of the wafer guide portion 12 and suppressing cracks of the wafer guide portion 12 during epitaxial growth processing and regeneration processing. In addition, it is possible to suppress a decrease in the in-plane distribution of the film thickness of the SiC epitaxial film Wb.

[0042] The angle of first chamfered portion 13 and the angle of second chamfered portion 14 with respect to the horizontal direction are preferably 10 degrees or more and 45 degrees or less. If the angle of the first chamfered portion 13 with respect to the horizontal direction is less than 10 degrees, the intersection angle between the inner peripheral surface 12b and the first chamfered portion 13 approaches a right-angled edge shape, which may cause cracks in the wafer guide portion 12 during regeneration processing of the inner peripheral surface 12b. Also, the deposit DP is more likely to protrude toward the central axis J than the inner peripheral surface 12b, which may cause the edge of the wafer W to come into contact with the deposit DP during transportation, resulting in transportation failure.

[0043] Similarly, if the angle of the second chamfered portion 14 with respect to the horizontal direction is less than 10 degrees, the intersection angle between the outer peripheral surface 12c and the second chamfered portion 14 approaches a right-angled edge shape, which may cause cracks in the wafer guide portion 12 during remanufacturing of the outer peripheral surface 12c. Also, the deposits DP tend to protrude radially outward from the outer peripheral surface 12c, and may come into contact with other members of the partition tube 7 and scatter or generate dust, which may cause particles.

[0044] Furthermore, if the angle of the first chamfered portion 13 with respect to the horizontal direction exceeds 45 degrees, the wafer guide portion 12 may become a barrier and inhibit the flow of the source gas G radially outward along the first surface Wa of the wafer W, possibly generating turbulence. In this case, as described above, the in-plane distribution of the film thickness of the SiC epitaxial film Wb may decrease. Therefore, by setting the angle of the first chamfered portion 13 and the angle of the second chamfered portion 14 relative to the horizontal direction to be greater than or equal to 10 degrees and less than or equal to 45 degrees, it is possible to suppress cracking of the wafer guide portion 12 during regeneration processing, problems with the transportation of the wafer W, the generation of particles, and a decrease in the in-plane distribution of the film thickness of the SiC epitaxial film Wb.

[0045] A first distance H4 in a direction along the central axis J between a first surface Wa facing upward in the wafer W and the upper surface 12a is preferably 1 mm or more and 2 mm or less. If the first distance H4 between the first surface Wa and the upper surface 12a is less than 1 mm, the edge of the wafer W may lift up if the wafer W is warped due to high temperature. In this case, when the wafer W rotates via the support 11 during the epitaxial growth process, the wafer W may move due to centrifugal force and jump out beyond the wafer guide portion 12. If the first distance H4 between the first surface Wa and the upper surface 12a exceeds 2 mm, as described above, the flow of the raw material gas G will be obstructed on the radially outer side and become turbulent, which may result in a decrease in the thickness of the SiC epitaxial film Wb and a decrease in the in-plane distribution. Therefore, by setting the first distance H4 between the first surface Wa and the upper surface 12a to 1 mm or more and 2 mm or less, it is possible to suppress the wafer W from jumping out of the wafer guide portion 12 and the decrease in the in-plane distribution of the film thickness of the SiC epitaxial film Wb.

[0046] A second distance W1 in the radial direction about the central axis J between the intersection of first chamfered portion 13 and upper surface 12a and inner circumferential surface 12b is preferably 0.5 mm or more and 10 mm or less. If the second distance W1 between the intersection of the first chamfered portion 13 and the upper surface 12a and the inner circumferential surface 12b is less than 0.5 mm, the wafer guide portion 12 may act as a barrier to inhibit the flow of the source gas G radially outward along the first surface Wa of the wafer W, thereby generating turbulence. In this case, as described above, the in-plane distribution of the thickness of the SiC epitaxial film Wb may decrease.

[0047] If the second distance W1 between the intersection of the first chamfered portion 13 and the top surface 12a and the inner peripheral surface 12b exceeds 10 mm, the intersection angle between the inner peripheral surface 12b and the first chamfered portion 13 approaches a right-angle edge shape, which may cause cracks in the wafer guide portion 12 during regeneration processing of the inner peripheral surface 12b. In addition, the deposit DP is more likely to protrude toward the central axis J than the inner peripheral surface 12b, which may cause contact with the deposit DP during transportation of the wafer W, resulting in transportation failure. Therefore, by setting the second distance W1 between the intersection of the first chamfered portion 13 and the upper surface 12a and the inner surface 12b to 0.5 mm or more and 10 mm or less, it is possible to suppress a decrease in the in-plane distribution of the film thickness of the SiC epitaxial film Wb, cracks of the wafer guide portion 12 during regeneration processing, and problems with the transportation of the wafer W.

[0048] The position along the central axis J where the inner circumferential surface 12b and the first chamfered portion 13 intersect is preferably above the position of the first surface Wa of the wafer W that faces upward. If the position where the inner circumferential surface 12b and the first chamfered portion 13 intersect is the same as or lower than the position of the first surface Wa, the high temperature may cause the wafer W to warp, causing the edge of the wafer W to lift up. In this case, when the wafer W rotates via the support table 11 during the epitaxial growth process, the wafer W may move due to centrifugal force and jump out beyond the wafer guide portion 12. Therefore, by positioning the position where the inner circumferential surface 12b and the first chamfered portion 13 intersect above the position of the first surface Wa, it is possible to prevent the wafer W from jumping out of the wafer guide portion 12.

[0049] In the above-mentioned SiC epitaxial growth process, the timing for replacing the wafer guide part 12 due to the accumulation of the deposit DP is preferably when the maximum axial distance H5 between the first surface Wa of the wafer W and the deposit DP is 2.5 mm or less, as shown in FIG. If the maximum distance H5 between the first surface Wa of the wafer W and the deposit DP exceeds 2.5 mm, the deposit DP will accumulate too much, and the regeneration process will become more time-consuming. Depending on the accumulation state of the deposit DP, the deposit DP may protrude radially inward from the inner peripheral surface 12b or radially outward from the outer peripheral surface 12c. By replacing the wafer guide portion 12 when the maximum distance H5 between the first surface Wa and the deposit DP is 2.5 mm or less, the effort required for regenerating the wafer guide portion 12 can be reduced and transportation failures of the wafer W can be suppressed.

[0050] According to at least one of the embodiments described above, by having a first chamfered portion 13 that connects the inner surface 12b and upper surface 12a of the wafer guide portion 12 and extends upward from the inner surface 12b toward the outer periphery, and a second chamfered portion 14 that connects the outer periphery 12c and upper surface 12a of the wafer guide portion 12 and extends upward from the outer periphery 12c toward the inner periphery, damage to the wafer guide portion 12 during regeneration can be suppressed.

[0051] Furthermore, according to at least one embodiment, by setting the thickness H1 of the wafer guide portion 12 to be 1.5 mm or more and 2.0 mm or less, it is possible to suppress damage to the wafer guide portion 12 during regeneration and a decrease in the in-plane distribution of the film thickness of the SiC epitaxial film Wb while suppressing cost increases.

[0052] Furthermore, according to at least one embodiment, by setting the angle of first chamfered portion 13 and the angle of second chamfered portion 14 relative to the horizontal direction to be greater than or equal to 10 degrees and less than or equal to 45 degrees, damage during regeneration of wafer guide portion 12, problems with transport of wafer W, generation of particles, and a decrease in the in-plane distribution of the film thickness of SiC epitaxial film Wb can be suppressed.

[0053] Furthermore, according to at least one embodiment, by setting the first distance H4 between the first surface Wa and the upper surface 12a to be 1 mm or more and 2 mm or less, it is possible to suppress the wafer W from protruding from the wafer guide portion 12 and the decrease in the in-plane distribution of the film thickness of the SiC epitaxial film Wb.

[0054] Furthermore, according to at least one embodiment, by setting the second distance W1 between the intersection of the first chamfered portion 13 and the upper surface 12a and the inner surface 12b to 0.5 mm or more and 10 mm or less, it is possible to suppress a decrease in the in-plane distribution of the film thickness of the SiC epitaxial film Wb, damage to the wafer guide portion 12 during regeneration, and poor transportation of the wafer W.

[0055] Furthermore, according to at least one embodiment, the position where the inner surface 12b and the first chamfered portion 13 intersect can be positioned above the position of the first surface Wa, thereby preventing the wafer W from jumping out of the wafer guide portion 12.

[0056] The present embodiment includes the following additional aspects. (Appendix 1) a wafer support device comprising: a support table having a support surface for supporting a wafer; a circular wafer guide portion that surrounds the periphery of the wafer supported on the support surface, centered on a central axis that extends in a normal direction to the support surface; a first chamfered portion that connects an inner peripheral surface and an upper surface of the wafer guide portion and extends upward as it moves from the inner peripheral surface to the outer peripheral side; and a second chamfered portion that connects an outer peripheral surface and the upper surface of the wafer guide portion and extends upward as it moves from the outer peripheral surface to the inner peripheral side. (Appendix 2) 2. The wafer support device of claim 1, wherein, in a cross section including the central axis, the first chamfered portion has a first inclined surface that slopes upward as it moves from the inner circumferential surface to the outer circumferential surface, and in the cross section, the second chamfered portion has a second inclined surface that slopes upward as it moves from the outer circumferential surface to the inner circumferential surface. (Appendix 3) 3. The wafer support device according to claim 1, wherein the thickness of the wafer guide portion in the direction along the central axis is 1.5 mm or more and 2.0 mm or less. (Appendix 4) 4. A wafer support device according to any one of claims 1 to 3, wherein a first distance in a direction along the central axis between a first surface of the wafer facing upward and the top surface is 1 mm or more and 2 mm or less. (Appendix 5) 5. The wafer support device of claim 1, wherein a second radial distance between an intersection of the first chamfered portion and the upper surface and the inner circumferential surface, centered on the central axis, is 0.5 mm or more and 10 mm or less. (Appendix 6) 6. The wafer support device of claim 1, wherein the position along the central axis where the inner circumferential surface and the first chamfered portion intersect is above the position of a first surface of the wafer that faces upward. (Appendix 7) 7. The wafer support device according to claim 1, wherein an angle of the first chamfered portion and an angle of the second chamfered portion with respect to the horizontal direction are greater than or equal to 10 degrees and less than or equal to 45 degrees. (Appendix 8) 8. The wafer support device according to claim 1, wherein at least a surface of the wafer guide portion is made of poly-SiC. (Appendix 9) 9. A SiC epitaxial growth apparatus comprising the wafer support apparatus according to any one of claims 1 to 8.

[0057] Although some embodiments of the present invention have been described, these embodiments are presented as examples and are not intended to limit the scope of the invention. These embodiments can be implemented in various other forms, and various omissions, substitutions, and modifications can be made without departing from the spirit of the invention. These embodiments and their modifications are included in the scope of the invention and its equivalents described in the claims, as well as in the scope and spirit of the invention. [Explanation of symbols]

[0058] Reference Signs List 1...SiC epitaxial growth apparatus, 10...wafer support apparatus, 11...support stand, 11A...support surface, 12...wafer guide portion, 12a...upper surface, 12b...inner peripheral surface, 12c...outer peripheral surface, 13...first chamfered portion, 13a...first inclined surface, 14...second chamfered portion, 14a...second inclined surface, J...center axis, W...wafer, Wa...first surface

Claims

1. a support table having a support surface for supporting a wafer; a wafer guide portion having an annular shape that surrounds the periphery of the wafer supported on the support surface, the wafer guide portion being centered on a central axis that extends in a normal direction to the support surface; a first chamfered portion that connects an inner peripheral surface and an upper surface of the wafer guide portion and extends in an upward direction from the inner peripheral surface toward the outer peripheral side; a second chamfered portion that connects an outer peripheral surface and the upper surface of the wafer guide portion and extends in an upward direction from the outer peripheral surface toward an inner peripheral side; A wafer support apparatus comprising:

2. In a cross section including the central axis, the first chamfered portion includes a first inclined surface that is inclined upward as it moves from the inner circumferential surface toward the outer circumferential surface, In the cross section, the second chamfered portion includes a second inclined surface that is inclined upward from the outer circumferential surface toward the inner circumferential surface.

2. The wafer support device of claim 1.

3. The thickness of the wafer guide portion in a direction along the central axis is 1.5 mm or more and 2.0 mm or less.

3. The wafer supporting device according to claim 1 or 2.

4. a first distance between a first surface facing upward in the wafer and the upper surface in a direction along the central axis is 1 mm or more and 2 mm or less; 3. The wafer supporting device according to claim 1 or 2.

5. A second distance in a radial direction about the central axis between an intersection of the first chamfered portion and the upper surface and the inner circumferential surface is 0.5 mm or more and 10 mm or less.

3. The wafer supporting device according to claim 1 or 2.

6. a position in a direction along the central axis where the inner circumferential surface and the first chamfered portion intersect is above a position of a first surface of the wafer facing upward; 3. The wafer supporting device according to claim 1 or 2.

7. The angle of the first chamfered portion and the angle of the second chamfered portion with respect to the horizontal direction are greater than or equal to 10 degrees and less than or equal to 45 degrees.

3. The wafer supporting device according to claim 1 or 2.

8. At least the surface of the wafer guide portion is made of poly-SiC.

3. The wafer supporting device according to claim 1 or 2.

9. A SiC epitaxial growth apparatus comprising the wafer support device according to claim 1 or 2.

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