Silicon carbide epitaxial growth apparatus and method for manufacturing silicon carbide epitaxial substrate

Abstract

The silicon carbide epitaxial growth device of the present disclosure comprises a substrate placement member (10) on which a semiconductor substrate (50) having a circular outer circumference part is placed, and a plug (20) mounted on the substrate placement member (10), wherein the substrate placement member (10) has a placement member substrate support unit (12) having a first substrate support surface (12a) that supports an outer edge region (51) of the back surface of the semiconductor substrate (50), and a placement member substrate facing unit (13) having a placement member substrate facing surface (13a) facing, across a gap, the inside surface of the outer edge region (51) of the semiconductor substrate (50). The plug (20) has the same height as the first substrate support surface (12a), and has a plug substrate support unit (22) having a second substrate support surface (22a) that supports a region not supported by the first substrate support surface (12a) of the outer edge region (51) of the semiconductor substrate (50), and that is continuously connected to the first substrate support surface (12a) at both ends.

Description

[Technical field]

[0001] The present disclosure relates to a silicon carbide epitaxial growth apparatus and a method for producing a silicon carbide epitaxial substrate. [Background technology]

[0002] Silicon carbide epitaxial substrates are semiconductor substrates using single crystal silicon carbide, single crystal silicon, etc. on which a silicon carbide epitaxial growth layer is formed, and are used in switching elements or rectifying elements of power conversion devices. Up until now, efforts have been made to improve silicon carbide epitaxial growth technology in order to improve the performance, manufacturing yield, etc. of these switching elements or rectifying elements.

[0003] Patent Document 1 discloses a technology that reduces the gap between the orientation flat (hereinafter referred to as "orientation flat") portion of a semiconductor substrate and the side wall of the substrate mounting portion of the susceptor when the semiconductor substrate is mounted on a susceptor of an epitaxial growth apparatus, thereby suppressing the flow of source gas for epitaxial growth onto the back surface of the semiconductor substrate and preventing the formation of a film on the back surface of the semiconductor substrate. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent Publication 2018-082100 (Fig. 3) Summary of the Invention [Problem to be solved by the invention]

[0005] However, in the susceptor shown in Patent Document 1, the gap between the orientation flat of the semiconductor substrate and the side wall of the substrate placement portion of the susceptor is not small enough, and source gas for epitaxial growth may flow onto the back surface of the semiconductor substrate, forming a film on the back surface of the semiconductor substrate. Also, the film formed on the back surface of the semiconductor substrate may reduce flatness, thereby decreasing the manufacturing yield.

[0006] The present disclosure has been made to solve the above-mentioned problems, and aims to provide a silicon carbide epitaxial growth apparatus that can prevent a film from being formed on the back surface of a semiconductor substrate when growing a silicon carbide epitaxial layer on the front surface of the semiconductor substrate, and a method for manufacturing a silicon carbide epitaxial substrate that can improve manufacturing yields. [Means for solving the problem]

[0007] The silicon carbide epitaxial growth apparatus of the present disclosure is a silicon carbide epitaxial growth apparatus including a substrate mounting member for mounting a semiconductor substrate having a circular outer periphery, and a plug mounted on the substrate mounting member, the substrate mounting member including a mounting member substrate support portion having a first substrate support surface for supporting an outer peripheral region of a rear surface of the semiconductor substrate, and a plug for supporting the rear surface of the semiconductor substrate. Back side Inside the fringe area The inner area of ​​the substrate a substrate facing portion of a mounting member having a substrate facing surface facing the first substrate support surface and spaced apart from the substrate supporting surface; the plug is a surface at the same height as the first substrate support surface; Outside The plug substrate support portion supports an area of ​​the edge region that is not supported by the first substrate support surface, and has a second substrate support surface that is continuously connected to the first substrate support surface at both ends. The second substrate support surface of the plug supports an inner peripheral region of a specific peripheral portion of the substrate, which is a peripheral portion of a specific shape other than a circular shape of the semiconductor substrate. .

[0008] The method for producing a silicon carbide epitaxial substrate of the present disclosure further includes a plug mounting step of detachably mounting a plug having a second substrate support surface on a substrate mounting member having a first substrate support surface that is the same height as the second substrate support surface and that is continuously connected to the second substrate support surface at both ends of the second substrate support surface; and supporting an outer edge region of a back surface of a semiconductor substrate having a circular outer periphery between the first substrate support surface and the second substrate support surface, The back surface of the semiconductor substrate Inside the fringe area The inner region of the substrate is the region The method includes a substrate mounting step of mounting a semiconductor substrate on the substrate mounting member and the plug so that the substrate is spaced from a substrate facing portion of the mounting member on the inner side of the substrate mounting member, and an epitaxial growth step of epitaxially growing silicon carbide on the surface of the semiconductor substrate. In the substrate mounting step, an inner peripheral region of a specific peripheral portion of the substrate, which is a peripheral portion of a specific shape other than a circle, of the semiconductor substrate is supported on the second substrate supporting surface of the plug. . Effect of the Invention

[0009] According to the present disclosure, it is possible to obtain a silicon carbide epitaxial growth apparatus and a method for manufacturing a silicon carbide epitaxial substrate that can prevent a film from being formed on the back surface of a semiconductor substrate when growing a silicon carbide epitaxial layer on the front surface of the semiconductor substrate, thereby improving manufacturing yield. [Brief description of the drawings]

[0010] [Figure 1] 2 is a schematic plan view showing a substrate mounting member and a plug of the silicon carbide epitaxial growth apparatus in the first embodiment. FIG. [Diagram 2] 2 is a schematic plan view showing a substrate mounting member of the silicon carbide epitaxial growth apparatus in the first embodiment. FIG. [Diagram 3] 2 is a schematic plan view showing a state in which a semiconductor substrate is placed on a substrate placement member and a plug of the silicon carbide epitaxial growth apparatus in the first embodiment. FIG. [Figure 4] 2 is a schematic cross-sectional view showing a state in which a semiconductor substrate is placed on a substrate placement member and a plug of the silicon carbide epitaxial growth apparatus in the first embodiment. FIG. [Diagram 5] 2 is an explanatory diagram of the outer periphery and rear surface of the semiconductor substrate in the first embodiment. [Figure 6] 2 is a schematic cross-sectional view showing a state in which a semiconductor substrate is placed on a substrate placement member and a plug of the silicon carbide epitaxial growth apparatus in the first embodiment. FIG. [Figure 7] 2 is a schematic cross-sectional view showing a state in which a semiconductor substrate is placed on a substrate placement member and a plug of the silicon carbide epitaxial growth apparatus in the first embodiment. FIG. [Figure 8] 11 is a schematic plan view showing a substrate mounting member and a plug of a silicon carbide epitaxial growth apparatus in accordance with the second embodiment. FIG. [Figure 9] 11 is a schematic plan view showing a substrate mounting member of a silicon carbide epitaxial growth apparatus in accordance with the second embodiment. FIG. [Figure 10]11 is a schematic cross-sectional view showing a state in which a semiconductor substrate is placed on a substrate placement member and a plug of a silicon carbide epitaxial growth apparatus in accordance with a second embodiment. FIG. [Figure 11] 11 is a schematic plan view showing a plug to be mounted on a substrate mounting member of a silicon carbide epitaxial growth apparatus in accordance with a second embodiment. FIG. [Figure 12] FIG. 11 is a schematic plan view showing a substrate mounting member and a plug of a silicon carbide epitaxial growth apparatus in the third embodiment. [Figure 13] FIG. 11 is a schematic plan view showing a substrate mounting member of a silicon carbide epitaxial growth apparatus in the third embodiment. [Figure 14] 11 is a schematic cross-sectional view showing a state in which a semiconductor substrate is placed on a substrate placement member and a plug of a silicon carbide epitaxial growth apparatus in accordance with a third embodiment. FIG. [Figure 15] FIG. 13 is a schematic plan view showing a substrate mounting member, a plug, and a cover ring of a silicon carbide epitaxial growth apparatus in accordance with a fourth embodiment. [Figure 16] FIG. 13 is a schematic cross-sectional view showing a substrate mounting member, a plug, and a cover ring of a silicon carbide epitaxial growth apparatus in accordance with a fourth embodiment, with a semiconductor substrate mounted thereon. [Figure 17] FIG. 13 is a schematic cross-sectional view showing a substrate mounting member, a plug, and a cover ring of a silicon carbide epitaxial growth apparatus in accordance with a fourth embodiment, with a semiconductor substrate mounted thereon. [Figure 18] FIG. 13 is a schematic cross-sectional view showing a substrate mounting member, a plug, and a cover ring of a silicon carbide epitaxial growth apparatus in accordance with a fourth embodiment, with a semiconductor substrate mounted thereon. [Figure 19] FIG. 13 is a schematic cross-sectional view showing a substrate mounting member, a plug, and a cover ring of a silicon carbide epitaxial growth apparatus in accordance with a fourth embodiment, with a semiconductor substrate mounted thereon. [Figure 20] FIG. 13 is a schematic cross-sectional view showing a substrate mounting member, a plug, and a cover ring of a silicon carbide epitaxial growth apparatus in accordance with a fourth embodiment, with a semiconductor substrate mounted thereon. [Figure 21]FIG. 13 is a schematic cross-sectional view showing a substrate mounting member, a plug, and a cover ring of a silicon carbide epitaxial growth apparatus in accordance with a fourth embodiment, with a semiconductor substrate mounted thereon. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] Hereinafter, a silicon carbide epitaxial growth apparatus and a method for manufacturing a silicon carbide epitaxial substrate according to an embodiment of the present disclosure will be described in detail with reference to the drawings. Here, the substrate mounting member provided in the silicon carbide epitaxial growth apparatus will be mainly described, and an epitaxial growth source gas supply unit, a film formation chamber, and the like will not be shown.

[0012] Embodiment 1 Fig. 1 is a plan view schematic diagram showing a substrate mounting member 10 and a plug 20 of a silicon carbide epitaxial growth apparatus in the present embodiment. Fig. 2 is a plan view schematic diagram showing the substrate mounting member 10 on which the plug 20 is not mounted. Fig. 3 is a plan view schematic diagram showing a state in which a semiconductor substrate 50 is mounted on the substrate mounting member 10 and the plug 20 of Fig. 1. Fig. 4 is a schematic diagram showing a cross section taken along dashed line A1-A2 in Fig. 3.

[0013] 1 to 4, substrate mounting member 10, on which semiconductor substrate 50 is mounted, has mounting member outer periphery 11, mounting member substrate support portion 12, mounting member substrate facing portion 13, and mounting member plug installation portion 14. Plug 20, which is detachably mounted on mounting member plug installation portion 14, has plug outer periphery 21, plug substrate support portion 22, and plug bottom portion 23.

[0014] The mounting member outer periphery 11 is located on the outer periphery of the substrate mounting member 10, and has a mounting member outer periphery inner wall 11a facing the end face of the semiconductor substrate 50, and a mounting member outer periphery upper stage 11b which is the upper stage of the mounting member outer periphery 11. Here, the mounting member outer periphery 11 is provided on the outer periphery side of the mounting member substrate support part 12 which will be described later.

[0015] The mounting member substrate support portion 12 is provided inside the mounting member outer peripheral portion 11, and has a first substrate supporting surface 12a that supports a first region 51a in a substrate outer edge region 51 on the rear surface of a semiconductor substrate 50 described below.

[0016] The mounting member substrate facing portion 13 is provided inside the mounting member substrate support portion 12, and has a mounting member substrate facing surface 13a that faces, at a distance from, a substrate inner region 52 on the rear surface of a semiconductor substrate 50 described later. The mounting member substrate facing surface 13a may be a flat surface or a curved surface.

[0017] 2, the mounting member plug installation portion 14 is provided in an area where the mounting member substrate support portion 12 is divided in the circumferential direction on the same plane as the mounting member substrate-facing surface 13a, and is a portion for mounting the plug 20. In FIG. 2, a part of the mounting member outer circumferential portion 11 is also divided in the circumferential direction, but the mounting member outer circumferential portion 11 does not have to be divided in the circumferential direction.

[0018] The plug outer periphery 21 is located on the outer periphery of the plug 20 and has a plug outer periphery inner wall 21a facing the end face of the semiconductor substrate 50, a plug outer periphery upper stage 21b which is the upper stage of the plug 20, and a plug outer periphery outer wall 21c which is the back surface side surface of the plug outer periphery inner wall 21a.

[0019] The plug substrate support portion 22 is an inner portion of the plug outer peripheral portion 21, and has a second substrate support surface 22a that supports a second region 51b in a substrate outer edge region 51 on the back surface of a semiconductor substrate 50 described later. The height from the substrate facing surface 13a of the mounting member to the second substrate support surface 22a is the same as the height from the substrate facing surface 13a of the mounting member to the first substrate support surface 12a. The second substrate support surface 22a supports a region of the substrate outer edge region 51 that is not supported by the first substrate support surface 12a. As shown in FIG. 1, the second substrate support surface 22a is continuously connected to the first substrate support surface 12a at both ends.

[0020] Here, "continuously connected" does not only mean that there is no gap between the first substrate support surface 12a and the second substrate support surface 22a, but also means that there is a small gap. This gap may be large enough to allow the plug 20 to be detachably mounted on the substrate mounting member 10, to prevent the epitaxial growth source gas from flowing into the back side of the semiconductor substrate 50 through this gap, and to prevent a film from being formed on the back side of the semiconductor substrate 50. This gap may be 0.1 mm or more and 3 mm or less, preferably 0.1 mm or more and 2 mm or less, and more preferably 0.1 mm or more and 1 mm or less.

[0021] The plug bottom 23 is the bottom of the plug 20 facing the mounting member plug installation part 14. FIG. 4 shows an example in which the mounting member plug installation part 14 and the plug bottom 23 are in contact with each other, but they may not be in contact with each other, and may be fixed by providing a positioning structure such as unevenness. Fixing the plug 20 suppresses the displacement of the plug 20 when mounting or removing the semiconductor substrate 50, and suppresses the generation of particles derived from the material and coating generated by friction between the plug 20 and the substrate mounting member 10. In addition, suppressing the displacement of the plug 20 can reduce the gap between the substrate mounting member 10, the plug 20, and the semiconductor substrate 50, and suppresses the flow of the source gas for epitaxial growth to the back surface of the semiconductor substrate 50.

[0022] 1, when such a substrate mounting member 10 and plug 20 are used, both ends of the plug 20 are surrounded by the mounting member outer periphery 11 and the mounting member substrate support portion 12, and the plug outer periphery outer wall 21c, which is the rear part of the plug 20, is in contact with and follows the divided recessed portion of the mounting member outer periphery 11, so that the gap between the substrate mounting member 10 and the plug 20 can be reduced. Then, as shown in FIGS. 3 and 4, the back surface of the semiconductor substrate 50 is supported by the first substrate support surface 12a and the second substrate support surface 22a, which are continuously connected, so that the space between the mounting member substrate facing surface 13a and the back surface of the semiconductor substrate 50 can be isolated from an epitaxial growth source gas supply unit (not shown) disposed outside the substrate mounting member 10, and the epitaxial growth source gas can be prevented from flowing into the back surface of the semiconductor substrate 50.

[0023] 4, the back surface of the semiconductor substrate 50 is supported by the first substrate supporting surface 12a and the second substrate supporting surface 22a, thereby forming a closed space surrounded by the back surface of the semiconductor substrate 50, the mounting member substrate facing portion 13, the mounting member outer peripheral portion 11, and the plug 20. In this way, the amount of source gas for epitaxial growth flowing into the back surface of the semiconductor substrate 50 can be reduced compared to the case where the plug 20 is not used.

[0024] 3, the plug 20 can be lifted up while the semiconductor substrate 50 is placed on the plug 20, and the back surface and the outer periphery of the semiconductor substrate 50 can be held, and good workability can be maintained. This makes it possible to suppress the generation of particles due to friction between tools such as tweezers, the substrate placement member 10, and the semiconductor substrate 50, or the retention of particles in the epitaxial growth apparatus, and suppress defects such as downfall and triangular defects that occur in the epitaxial growth layer.

[0025] 5 is an explanatory diagram of the periphery and rear surface of a semiconductor substrate 50. A substrate outer edge region 51 on the rear surface of the semiconductor substrate 50 is composed of a first region 51a and a second region 51b. The first region 51a is a region that is directly supported by the first substrate support surface 12a of the substrate mounting member 10. The second region 51b is a region that is directly supported by the second substrate support surface 22a of the plug 20. A substrate inner region 52 on the rear surface of the semiconductor substrate 50 is a region on the inner side of the substrate outer edge region 51 on the rear surface of the semiconductor substrate 50, and faces the mounting member substrate facing surface 13a of the substrate mounting member 10.

[0026] Substrate outer periphery 53 indicates the entire periphery of semiconductor substrate 50, and is composed of substrate circular outer periphery 53a and substrate specific outer periphery 53b. Substrate circular outer periphery 53a is a circular outer periphery portion of semiconductor substrate 50. Substrate specific outer periphery 53b is an outer periphery portion of semiconductor substrate 50 having a specific shape other than circular, such as an orientation flat portion or a notch portion. Here, semiconductor substrate 50 may be circular and not include substrate specific outer periphery 53b.

[0027] 5 shows an example in which the inside of the substrate specific outer periphery 53b is the second region 51b, but the inside of the substrate circular outer periphery 53a can also be the second region 51b, in which case a part or all of the inside of the substrate specific outer periphery 53b is the first region 51a. In this way, the inside of the substrate specific outer periphery 53b of the semiconductor substrate 50 can be supported by either the first substrate support surface 12a or the second substrate support surface 22a, improving the workability when placing the semiconductor substrate 50 on the substrate placement member 10. Therefore, it is possible to suppress the generation of particles due to friction between a tool such as tweezers, the substrate placement member 10, and the semiconductor substrate 50, or the retention of particles in the epitaxial growth device, and it is possible to suppress defects such as downfall and triangular defects that occur in the epitaxial growth layer.

[0028] In this way, when the substrate outer edge region 51 is supported by the substrate mounting member 10 and the plug 20, the heat conduction from the substrate mounting member 10 to the semiconductor substrate 50 is made uniform, and the semiconductor substrate 50 is heated uniformly, compared to a case where only a part of the substrate outer edge region 51 is not supported, such as when the inside of the substrate circular outer periphery 53a is supported but the inside of the substrate specific outer periphery 53b is not supported. This makes it possible to improve the uniformity of the film thickness, carrier concentration, etc. of the epitaxial growth layer.

[0029] In addition, a heating device (not shown) using an induction heating method, resistance heating method, or the like is disposed inside the epitaxial growth apparatus, but the method of heating the semiconductor substrate 50 preferably reduces the contact area between the substrate mounting member 10 and the semiconductor substrate 50 to suppress heat conduction and mainly utilizes radiation or convection. Therefore, by providing the substrate mounting member 10 with a mounting member substrate facing portion 13 that does not contact the semiconductor substrate 50 and supporting the substrate outer edge region 51 of the semiconductor substrate 50 with the substrate mounting member 10 and the plug 20, the semiconductor substrate 50 can be heated mainly by radiation or convection while suppressing heat conduction.

[0030] Here, the optimum value of the distance between the substrate-facing surface 13a of the mounting member and the back surface of the semiconductor substrate 50 varies depending on the diameter of the semiconductor substrate 50, the flow rate of the source gas for epitaxial growth, the heat insulating material structure of the epitaxial growth apparatus, the epitaxial growth conditions, etc., but it is preferably about 0.5 mm or more and 2 mm or less. By adjusting it within this range, it becomes easy to control the heat radiation and heat reflection when heating the semiconductor substrate 50, the semiconductor substrate 50 is heated uniformly during epitaxial growth, and the film thickness, carrier concentration, etc. of the epitaxial growth layer in the substrate outer edge region 51 and the substrate inner region 52 can be made equal.

[0031] Next, an example of this embodiment will be described. In the case of using a silicon carbide single crystal substrate having an orientation flat as the substrate specific outer periphery 53b of the semiconductor substrate 50, a diameter of 150 mm, and a length of a perpendicular line from the center of the substrate to the orientation flat of 71.1 mm, the clearance between the substrate circular outer periphery 53a of the silicon carbide single crystal substrate and the mounting member outer periphery inner wall 11a generated by mounting the silicon carbide single crystal substrate on the first substrate support surface 12a is set to 0.6 mm, the inner diameter of the circular mounting member substrate facing portion 13 is set to 70.5 mm, and the width W of the first substrate support surface 12a is determined to be 5.1 mm from the following formula 1. W = (150 + 1.2) / 2 - 70.5 (mm) (Formula 1)

[0032] Here, consideration is given to the tolerance of the diameter of the silicon carbide single crystal substrate, the processing accuracy of the substrate mounting member 10, the ease of mounting or retrieving the silicon carbide single crystal substrate, the thermal conduction to the silicon carbide single crystal substrate, etc. The clearance between the edge of the silicon carbide single crystal substrate and the outer peripheral inner wall 11a of the mounting member is set to 0.6 mm, but it is sufficient that the edge of the silicon carbide single crystal substrate and the outer peripheral inner wall 11a of the mounting member do not collide with each other during epitaxial growth, and it is sufficient that the clearance is approximately 1 / 150 to 1 / 100 times the radius of the silicon carbide single crystal substrate at room temperature. Although the width of first substrate support surface 12a is set to 5.1 mm, it is sufficient that first substrate support surface 12a can support the silicon carbide single crystal substrate even if the silicon carbide single crystal substrate warps during epitaxial growth, and it is preferable to reduce the width of first substrate support surface 12a in order to reduce the contact area of ​​substrate outer edge region 51 of the silicon carbide single crystal substrate during epitaxial growth and mitigate the increase in temperature near substrate outer periphery 53. When the increase in temperature near substrate outer periphery 53 is mitigated, the film thickness, carrier concentration, etc. of the epitaxially grown layer near substrate outer periphery 53 and the region inside it can be made equivalent.

[0033] In this way, plug 20, together with substrate mounting member 10, supports substrate outer edge region 51 on the back surface of semiconductor substrate 50, and isolates the space between substrate inner region 52 of semiconductor substrate 50 and mounting member substrate facing portion 13 from an epitaxial growth source gas supply unit (not shown) disposed outside substrate mounting member 10, thereby preventing the epitaxial growth source gas from flowing into the back surface of semiconductor substrate 50. Thus, when a silicon carbide epitaxial layer is grown on the front surface of semiconductor substrate 50, a silicon carbide epitaxial growth apparatus can be obtained that can prevent a film from being formed on the back surface of semiconductor substrate 50 and improve manufacturing yield.

[0034] In addition, the temperature difference between the inside of the circular outer periphery 53a of the substrate and the inside of the specific outer periphery 53b of the substrate during heating of the semiconductor substrate 50 is reduced, and the in-plane uniformity of the heating of the semiconductor substrate 50 can be improved. The uniformity of the film thickness, carrier concentration, etc. of the epitaxial growth layer can be improved. Furthermore, the removable plug 20 can maintain good operability in placing or retrieving the semiconductor substrate 50, and can suppress the generation of particles due to friction between tools such as tweezers, the substrate placement member 10, and the semiconductor substrate 50, or the retention of particles in the epitaxial growth device, and can suppress defects such as downfall and triangular defects that occur in the epitaxial growth layer.

[0035] The materials of the substrate mounting member 10 and the plug 20 have a gas permeability of 8×10 -6 m 2 It is preferable to use a material having a low reactivity with the epitaxial growth source gas, carrier gas, etc. at a flow rate of 100 / s or less, and graphite coated with silicon carbide, tantalum carbide, etc. can be used. In particular, it is preferable that the mounting member substrate-facing surface 13a, the mounting member outer peripheral inner wall 11a, the plug outer peripheral inner wall 21a, and the second substrate support surface 22a have a melting point of 1700°C or more and are made of a material other than silicon carbide, such as tantalum carbide. This is to prevent the substrate mounting member 10 or the plug 20 from being etched by the epitaxial growth source gas, etc., and to prevent the gap between the substrate mounting member 10 or the plug 20 and the semiconductor substrate 50 from expanding. Other materials that can be used include metals such as niobium, tungsten, hafnium, and zirconium, carbides of these metals, and pyrolytic carbon, but these may be selected in consideration of warping due to heating, gas permeation, etc.

[0036] Moreover, the height from the first substrate support surface 12a to the top of the mounting member outer periphery upper stage 11b and the height from the second substrate support surface 22a to the top of the plug outer periphery upper stage 21b at room temperature are preferably equal to or greater than the thickness of the semiconductor substrate 50 at room temperature. In other words, the mounting member outer periphery upper stage 11b and the plug outer periphery upper stage 21b are preferably formed at a height equal to or greater than the surface of the semiconductor substrate 50. Furthermore, it is preferable that the height of the mounting member outer periphery upper stage 11b and the height of the plug outer periphery upper stage 21b are 0.1 mm to 0.9 mm higher than the thickness of the semiconductor substrate 50. In this way, when the source gas for epitaxial growth is supplied from the lateral direction of FIG. 4, the source gas for epitaxial growth is not directly sprayed onto the surface of the semiconductor substrate 50, and the gas flow near the substrate periphery 53 is less likely to be disturbed. As a result, the flow resistance of the epitaxial growth source gas to the back surface of the semiconductor substrate 50 is reduced, preventing the formation of a film on the back surface of the semiconductor substrate 50, while the thickness, carrier concentration, etc. of the epitaxial growth layer in the substrate outer edge region 51 and the substrate inner region 52 can be made equivalent.

[0037] Here, the height from the second substrate support surface 22a to the top of the plug outer periphery upper stage 21b need only be equal to or less than the height from the first substrate support surface 12a to the top of the mounting member outer periphery upper stage 11b, and it is preferable that it be the same height as the mounting member outer periphery upper stage 11b.

[0038] 6, the mounting member outer peripheral upper stage 11b and the plug outer peripheral upper stage 21b may have an inclination such that the height decreases in a direction from the mounting member outer peripheral stage 11 toward the mounting member substrate-facing surface 13a or the semiconductor substrate 50. By inclining the mounting member outer peripheral stage 11b, when the source gas for epitaxial growth is supplied from the lateral direction in FIG. 6, the source gas for epitaxial growth and the like can easily flow toward the surface of the semiconductor substrate 50, making it difficult for turbulence to occur in the gas flow. The angle of this inclination may be adjusted according to the flow rate of the source gas for epitaxial growth and the like.

[0039] 7, the mounting member outer periphery upper stage 11b may have a slope such that the height increases in a direction from the mounting member outer periphery 11 toward the mounting member substrate-facing surface 13a or the semiconductor substrate 50. In this case, however, it is preferable that the uppermost portions of the mounting member outer periphery upper stage 11b and the plug outer periphery upper stage 21b are higher than the surface of the semiconductor substrate 50 near the substrate periphery 53 by about 0.1 mm to 0.9 mm at room temperature. Note that, although an example is shown in FIG. 6 in which the mounting member outer periphery upper stage 11b and the plug outer periphery upper stage 21b have the same slope, either the mounting member outer periphery upper stage 11b or the plug outer periphery upper stage 21b may have a slope, as shown in an example in FIG.

[0040] Moreover, the mounting member outer peripheral upper stage 11b and the plug outer peripheral upper stage 21b are preferably made of silicon carbide, which is the same material as the epitaxial growth layer. In this way, the adhesion between the film formed on the mounting member outer peripheral upper stage 11b or the plug outer peripheral upper stage 21b by the source gas for epitaxial growth and the mounting member outer peripheral upper stage 11b or the plug outer peripheral upper stage 21b is improved, and the generation of particles due to peeling of the film can be suppressed.

[0041] In addition, although an example has been shown in which the substrate mounting member 10 and the plug 20 each have the mounting member outer periphery 11 and the plug outer periphery 21, the substrate mounting member 10 and the plug 20 do not have to have the mounting member outer periphery 11 and the plug outer periphery 21, respectively.

[0042] With such a configuration, it is possible to obtain a silicon carbide epitaxial growth apparatus that can prevent the source gas for epitaxial growth from flowing into the back surface of the semiconductor substrate 50, and can prevent a film from being formed on the back surface of the semiconductor substrate when growing a silicon carbide epitaxial layer on the front surface of the semiconductor substrate, thereby improving the manufacturing yield. It is also possible to improve the in-plane uniformity of heating of the semiconductor substrate 50 and suppress the generation of particles.

[0043] Embodiment 2 In the first embodiment, a part of the mounting member outer peripheral portion 11 and the mounting member substrate support portion 12 are divided in the circumferential direction to provide the mounting member plug installation portion 14, a plug 20 is mounted on the mounting member plug installation portion 14, and the inside of the substrate specific outer peripheral portion 53b of the semiconductor substrate 50 is supported by either the first substrate support surface 12a or the second substrate support surface 22a. In the present embodiment, however, an example is described in which the mounting member outer peripheral portion 11 and the mounting member substrate support portion 12 are not divided in the circumferential direction, a mounting member plug installation portion 14 having a plug support surface 12b is provided, a plug 20 is mounted on the mounting member plug installation portion 14, and the inside of the substrate specific outer peripheral portion 53b of the semiconductor substrate 50 is supported by the second substrate support surface 22a of the plug 20. The rest of the configuration is the same as in the first embodiment.

[0044] Fig. 8 is a schematic plan view showing a substrate mounting member 10 of a silicon carbide epitaxial growth apparatus in the present embodiment and a plug 20 having a plug seat 23a. Fig. 9 is a schematic plan view showing the substrate mounting member 10 on which no plug 20 is mounted. Fig. 10 is a schematic diagram showing a cross section taken along dashed line B1-B2 in Fig. 8, and shows a state in which a semiconductor substrate 50 is mounted thereon for clarity of explanation.

[0045] As shown in FIG. 9, the mounting member outer peripheral portion 11 and the mounting member substrate support portion 12 are continuous in the circumferential direction. Also, the mounting member has a plug support surface 12b that is continuous at the same height as the first substrate support surface 12a. As shown in FIG. 8 and FIG. 10, the plug 20 is mounted so that the plug seat surface 23a is placed on the plug support surface 12b. Furthermore, the plug outer peripheral portion outer wall 21c of the upper part of the plug seat surface 23a is in contact with and aligned with the mounting member outer peripheral portion inner wall 11a, and is mounted at the position of the mounting member plug installation portion 14. And, as in the first embodiment, the second substrate support surface 22a is continuously connected to the first substrate support surface 12a at both ends. Also, the second substrate support surface 22a supports the second region 51b inside the substrate specific peripheral portion 53b of the semiconductor substrate 50.

[0046] Here, the substrate outer edge region 51 inside the substrate specific outer periphery 53b is basically entirely supported by the second substrate support surface 22a, but the vicinity of the boundary between the substrate specific outer periphery 53b and the substrate circular outer periphery 53a may be supported by the first substrate support surface 12a without being supported by the second substrate support surface 22a. The substrate mounting member 10 and the plug 20 can be designed and a surface for supporting the vicinity of the boundary between the substrate specific outer periphery 53b and the substrate circular outer periphery 53a can be selected by comprehensively taking into consideration the flow resistance of the source gas for epitaxial growth to the back surface of the semiconductor substrate 50, the operability of mounting and recovering the plug 20, the processing accuracy of the substrate mounting member 10 and the plug 20, the shape and dimensions of the semiconductor substrate 50, and the like.

[0047] By supporting the inside of the substrate specific outer periphery 53b with the second substrate supporting surface 22a, it is not necessary to provide a wide first substrate supporting surface 12a as in embodiment 1, which supports the inside of the substrate specific outer periphery 53b regardless of the position of the substrate specific outer periphery 53b on the substrate mounting member 10. The width of the first substrate supporting surface 12a can be narrowed to narrow the contact area between the semiconductor substrate 50 and the first substrate supporting surface 12a.

[0048] This can suppress the heat conduction from the substrate mounting member 10 or the plug 20 to the semiconductor substrate 50, improving the uniformity of heating of the semiconductor substrate 50. Therefore, the thickness, carrier concentration, etc. of the epitaxially grown layer in the substrate outer edge region 51 and the substrate inner region 52 can be made equal to each other.

[0049] Here, even if the width of the first substrate support surface 12a is narrowed, the inside of the substrate outer periphery 53 can be supported by the substrate mounting member 10 and the plug 20, so that the space between the mounting member substrate facing surface 13a and the back surface of the semiconductor substrate 50 can be isolated from the epitaxial growth raw material gas supply section (not shown) that is located outside the substrate mounting member 10, thereby preventing the epitaxial growth raw material gas from flowing onto the back surface of the semiconductor substrate 50.

[0050] Also, the length over which the first substrate support surface 12a or the second substrate support surface 22a supports the back surface of the semiconductor substrate 50, in other words, the width of the substrate outer edge region 51, is different between the inside of the substrate circular outer periphery 53a and the inside of the substrate specific outer periphery 53b in the first embodiment, but can be adjusted to be equal in the present embodiment. Therefore, in the present embodiment, even if the semiconductor substrate 50 warps during epitaxial growth, the inside of the substrate outer periphery 53 is uniformly supported, and the flow resistance of the epitaxial growth source gas and the like to the back surface of the semiconductor substrate 50 can be kept high even in the substrate specific outer periphery 53b. Also, the film thickness, carrier concentration, and the like of the epitaxial growth layer near the substrate circular outer periphery 53a and the substrate specific outer periphery 53b can be made equal, and the formation of a film on the back surface of the semiconductor substrate 50 can be prevented.

[0051] Next, an example of this embodiment will be described. When using a silicon carbide single crystal substrate having an orientation flat as the substrate specific outer periphery 53b of semiconductor substrate 50, a diameter of 150 mm, a length of a perpendicular line from the center of the substrate to the orientation flat portion of 71.1 mm, and a length of a straight portion of the orientation flat portion of 47.5 mm, the clearance between the substrate circular outer periphery 53a of the silicon carbide single crystal substrate and the mounting member outer periphery inner wall 11a generated by mounting the silicon carbide single crystal substrate on the first substrate support surface 12a can be determined to be 0.3 mm, the radius of the circular mounting member substrate facing portion 13 can be determined to be 74 mm, the width of the first substrate support surface 12a can be determined to be 1.3 mm, and the width of the second substrate support surface 22a can be determined to be 1.5 mm.

[0052] Here, as in the first embodiment, the tolerance of the diameter of the silicon carbide single crystal substrate, the machining accuracy of the substrate mounting member 10, the workability in mounting or retrieving the silicon carbide single crystal substrate, the thermal conduction to the silicon carbide single crystal substrate, etc. are taken into consideration. The clearance between the end of the silicon carbide single crystal substrate and the outer peripheral inner wall 11a of the mounting member is set to 0.3 mm, but it is sufficient that the end of the silicon carbide single crystal substrate and the outer peripheral inner wall 11a of the mounting member do not collide with each other during epitaxial growth, and it is sufficient that the clearance is about 1 / 200 times or more and 1 / 100 times or less of the radius of the silicon carbide single crystal substrate at room temperature. In addition, the width of the first substrate support surface 12a is set to 1.3 mm, and the width of the second substrate support surface 22a is set to 1.5 mm, but it is sufficient that the silicon carbide single crystal substrate can be supported even if it is warped during epitaxial growth, and it is preferable that the clearance is 0.4 mm or more and 2 mm or less.

[0053] In this way, the temperature rise near the outer periphery 53 of the substrate is mitigated, and the film thickness, carrier concentration, and the like of the epitaxially grown layer can be made equivalent between the substrate outer edge region 51 and the substrate inner region 52. As shown in Fig. 11, the plug 20 may be provided with a structure for facilitating installation or recovery, for example, a plug hole 24 for grasping with tweezers, in the upper part 21b of the outer periphery of the plug.

[0054] Embodiment 3 In the first embodiment, a part of the mounting member outer periphery 11 and the mounting member substrate support portion 12 are divided in the circumferential direction to provide the mounting member plug installation portion 14, where plug 20 is installed, and the inside of the substrate specific outer periphery 53b of the semiconductor substrate 50 is supported by either the first substrate support surface 12a or the second substrate support surface 22a, but in this embodiment, an example will be described in which the mounting member outer periphery 11 is not divided, and the inside of the substrate specific outer periphery 53b of the semiconductor substrate 50 is supported by the second substrate support surface 22a. The rest of the configuration is the same as in the first embodiment.

[0055] Fig. 12 is a plan view schematic diagram showing a substrate mounting member 10 of a silicon carbide epitaxial growth apparatus in the present embodiment and plugs 20. Fig. 13 is a plan view schematic diagram showing the substrate mounting member 10 on which no plugs 20 are mounted. Fig. 14 is a schematic diagram showing a cross section taken along dashed line C1-C2 in Fig. 12, and for clarity of explanation, shows a state in which a semiconductor substrate 50 is mounted.

[0056] As shown in Fig. 13, the width of the first substrate support surface 12a is narrow, and a mounting member plug installation portion 14 is provided at a portion where the mounting member substrate support portion 12 is divided in the circumferential direction. As shown in Figs. 12 and 14, the plug 20 is mounted at the position of the mounting member plug installation portion 14 such that the plug outer peripheral portion outer wall 21c contacts and runs along the mounting member outer peripheral portion inner wall 11a. Similarly to the first embodiment, the second substrate support surface 22a is continuously connected to the first substrate support surface 12a at both ends.

[0057] In this way, the gap between the first substrate support surface 12a and the second substrate support surface 22a can be made smaller, so that the flow resistance of the epitaxial growth source gas to the back surface of the semiconductor substrate 50 is increased compared to the second embodiment, and the flow of gas to the back surface is further suppressed. In addition, the width of the substrate outer edge region 51 can be made smaller while supporting the back surface of the semiconductor substrate 50, so that the heat conduction from the substrate mounting member 10 or the plug 20 to the semiconductor substrate 50 is suppressed, and the uniformity of the heating of the semiconductor substrate 50 is improved. In addition, the uniformity of the film thickness, carrier concentration, etc. of the epitaxial growth layer can be improved.

[0058] Also, as in the second embodiment, the width of the substrate outer edge region 51 can be made equal inside the substrate circular outer periphery 53a and the substrate specific outer periphery 53b. Therefore, even if the semiconductor substrate 50 warps during epitaxial growth, the inside of the substrate outer periphery 53 is uniformly supported, and the flow resistance of the epitaxial growth source gas and the like to the back surface of the semiconductor substrate 50 can be kept high even in the substrate specific outer periphery 53b. Therefore, the film thickness, carrier concentration, and the like of the epitaxial growth layer near the substrate circular outer periphery 53a and the substrate specific outer periphery 53b can be made equal, and the formation of a film on the back surface of the semiconductor substrate 50 can be prevented.

[0059] In this embodiment, the dimensions of each part of the substrate mounting member 10 and the plug 20 can be determined in the same manner as in embodiment 2. Furthermore, the plug 20 may be provided with a structure for facilitating installation or recovery, for example, a hole for grasping with tweezers.

[0060] Embodiment 4 In this embodiment, an example will be described in which a cover ring 30 is attached to the outside of the mounting member outer circumferential portion 11. The other configurations are the same as those in the first to third embodiments. Here, the substrate mounting member 10 and the plug 20 in the third embodiment will be described as an example.

[0061] Fig. 15 is a plan view showing a substrate mounting member 10, a plug 20, and a cover ring 30 of a silicon carbide epitaxial growth apparatus in the present embodiment. Fig. 16 is a schematic diagram showing a cross section taken along dashed line D1-D2 in Fig. 15, and shows a state in which a semiconductor substrate 50 is mounted thereon for the sake of clarity.

[0062] As shown in FIG. 15 and FIG. 16, a ring-shaped cover ring 30 is placed on the outer periphery of the mounting member 11, and a ring-shaped ring support surface 11c is provided on the outer periphery of the mounting member 11. The cover ring 30 has a ring inner wall 30a that faces or contacts the ring support surface 11c of the mounting member 11, and a flat upper ring stage 30b on the upper part of the cover ring 30. Here, when the cover ring 30 and the semiconductor substrate 50 are placed on the substrate mounting member 10, the uppermost part of the ring upper stage 30b may be higher than the surface of the semiconductor substrate 50. In addition, the uppermost part of the ring upper stage 30b is preferably higher than the upper stage 11b of the mounting member 11 and the upper stage 21b of the plug 21. Furthermore, the uppermost part of the ring upper stage 30b is preferably higher than the surface of the semiconductor substrate 50 at the substrate periphery 53 by about 0.1 mm to 0.9 mm at room temperature.

[0063] In this way, when the source gas for epitaxial growth is supplied from the lateral direction in FIG. 16, the source gas for epitaxial growth is not directly sprayed onto the surface of the semiconductor substrate 50, and the flow of the gas near the outer periphery 53 of the substrate is less likely to be disturbed. Then, the flow resistance of the source gas for epitaxial growth to the rear surface of the semiconductor substrate 50 is reduced, and it is possible to prevent a film from being formed on the rear surface of the semiconductor substrate 50, and it is possible to make the thickness, carrier concentration, etc. of the epitaxial growth layer in the outer peripheral region 51 of the substrate and the inner region 52 of the substrate equal. In addition, since the source gas for epitaxial growth flows toward the front surface of the semiconductor substrate 50 along the upper ring stage 30b, it is possible to adjust the gas flow rate flowing into the front surface of the semiconductor substrate 50, and it is possible to suppress the stagnation of gas near the outer periphery 53 of the substrate, and it is possible to reduce the source gas flowing into the rear surface of the semiconductor substrate 50. Therefore, the film thickness, carrier concentration, etc. of the epitaxially grown layer near the substrate circular outer periphery 53a and the substrate specific outer periphery 53b can be made equal, and formation of a film on the back surface of the semiconductor substrate 50 can be prevented.

[0064] Here, if a film is formed on the cover ring 30 with use, it may hinder the flow of the source gas for epitaxial growth to the semiconductor substrate 50, causing disturbance. In addition, dimensional tolerances occurring when processing the substrate mounting member 10 and the cover ring 30, epitaxial growth conditions, and the like may also cause disturbance in the flow of the source gas for epitaxial growth to the semiconductor substrate 50. For this reason, by appropriately replacing the cover ring 30, the position of the upper ring stage 30b can be adjusted to prevent disturbance in the flow of the source gas for epitaxial growth to the semiconductor substrate 50. Here, if the film formed on the cover ring 30 becomes thick, the film stress increases, which may cause damage to the film and generate particles, so by replacing the cover ring 30 before the particles are generated, the generation of particles can be suppressed.

[0065] The material of the cover ring 30 can be graphite coated with silicon carbide, tantalum carbide, or the like. In particular, the upper ring stage 30b is preferably made of silicon carbide, which is the same material as the epitaxial growth layer. In this way, the adhesion between the film of the upper ring stage 30b formed by the source gas for epitaxial growth and the upper ring stage 30b is improved, and the generation of particles due to peeling of this film can be suppressed.

[0066] The upper ring stage 30b may have a slope in which the height decreases as shown in FIG. 17 or a slope in which the height increases as shown in FIG. 18 in the direction from the outside of the cover ring 30 toward the substrate-facing surface 13a of the mounting member or the semiconductor substrate 50, and can be determined according to the epitaxial growth conditions. Even when the upper ring stage 30b has a slope, as in the flat case shown in the above example, when the cover ring 30 and the semiconductor substrate 50 are placed on the substrate mounting member 10, the uppermost part of the upper ring stage 30b may be higher than the surface of the semiconductor substrate 50 and may be higher than the upper stage 11b of the mounting member outer periphery and the upper stage 21b of the plug outer periphery. In addition, the uppermost part of the upper ring stage 30b is preferably higher than the surface of the semiconductor substrate 50 at the substrate periphery 53 at room temperature by about 0.1 mm to 0.9 mm.

[0067] Also, the cover ring 30 may be shaped to cover the upper stage 11b of the outer periphery of the mounting member as shown in Figures 19 to 21. In this case, the upper stage 11b of the outer periphery of the mounting member and the ring support surface 11c of the outer periphery of the mounting member may be shaped to fit the ring inner wall 30a without any gaps, and may be shaped like a step or triangle as shown in Figures 19 to 21. The shape of the cover ring 30 may be appropriately selected taking into consideration the ease of attachment and recovery of the cover ring 30, the amount of particles generated, etc.

[0068] Furthermore, when a film is formed on the covering ring 30 with use, the thickness of the film varies depending on the portion of the covering ring 30, which may cause the covering ring 30 to warp. For this reason, the covering ring 30 may be processed to have slits, irregularities, or the like to prevent the covering ring 30 from warping. When processing the covering ring 30 with slits, irregularities, or the like, care should be taken to prevent turbulence in the flow of the epitaxial growth source gas toward the semiconductor substrate 50.

[0069] Embodiment 5. In this embodiment, a method for manufacturing a silicon carbide epitaxial substrate will be described. The method for manufacturing a silicon carbide epitaxial substrate includes a plug mounting step of mounting a plug 20 supporting a substrate outer edge region 51 on the back surface of a semiconductor substrate 50 on a substrate mounting member 10, a substrate mounting step of separating the mounting member substrate facing surface 13a from the back surface of the semiconductor substrate 50 and mounting the semiconductor substrate 50 on the first substrate support surface 12a of the substrate mounting member 10 and the second substrate support surface 22a of the plug 20, an epitaxial growth step of epitaxially growing silicon carbide on the front surface of the semiconductor substrate 50, and a recovery step of lifting the plug 20 with the semiconductor substrate 50 mounted on the second substrate support surface 22a after the epitaxial growth step to recover the semiconductor substrate 50.

[0070] In the plug mounting step, plug 20 is grasped with tweezers or the like, and mounted, for example, by fitting plug 20 into mounting member plug installation portion 14 in the region where mounting member substrate support portion 12 is divided in the circumferential direction in a plan view. Here, when using substrate mounting member 10 in which mounting member substrate support portion 12 is not divided in the circumferential direction as shown in embodiment 2, plug 20 having plug seat surface 23a is mounted on first substrate support surface 12a of mounting member plug installation portion 14.

[0071] In the substrate mounting step, in the case of the substrate mounting member 10 and plug 20 shown in the first embodiment, as described above, the semiconductor substrate 50 may be mounted in any manner such that the substrate outer edge region 51 on the back surface of the semiconductor substrate 50 corresponds to the first substrate supporting surface 12a and the second substrate supporting surface 22a. In the examples shown in the second to fourth embodiments, the semiconductor substrate 50 is mounted so that the second substrate supporting surface 22a supports the back surface of the semiconductor substrate 50 inside the substrate specific outer periphery 53b.

[0072] In the epitaxial growth process, the substrate mounting member 10 and the semiconductor substrate 50 are heated by a heating device, and a source gas for epitaxial growth is flowed from an epitaxial growth source gas supply section arranged in a horizontal direction to the semiconductor substrate 50 mounted on the substrate mounting member 10, to form an epitaxial growth layer on the semiconductor substrate 50.

[0073] In the recovery step, after the epitaxial growth step, the plug 20 is lifted with the semiconductor substrate 50 placed on the second substrate support surface 22a, and the semiconductor substrate 50 is recovered with vacuum tweezers or the like. This simplifies recovery of the semiconductor substrate 50, prevents friction between the semiconductor substrate 50, the substrate mounting member 10, the plug 20, and a jig such as tweezers, and suppresses the generation of particles.

[0074] In addition, the method may further include a cover ring attachment step of attaching a cover ring 30 to the mounting member outer peripheral ring support surface 11c of the substrate mounting member 10, and after the cover ring attachment step and the plug mounting step are performed in any order, the substrate mounting step and epitaxial growth step may be performed in this order.

[0075] In this way, when a silicon carbide epitaxial layer is grown on the front surface of a semiconductor substrate, a film can be prevented from being formed on the back surface of the semiconductor substrate, thereby providing a method for manufacturing a silicon carbide epitaxial substrate that can improve manufacturing yields.

[0076] In addition to the above, the embodiments can be freely combined, any of the components of the embodiments can be modified, or any of the components of the embodiments can be omitted. [Explanation of symbols]

[0077] 10 substrate mounting member, 11 mounting member outer periphery, 11a mounting member outer periphery inner wall, 11b mounting member outer periphery upper stage, 11c mounting member outer periphery ring support surface, 12 mounting member substrate support portion, 12a first substrate support surface, 12b plug support surface, 13 mounting member substrate facing portion, 13a mounting member substrate facing surface, 14 mounting member plug installation portion, 20 plug, 21 plug outer periphery, 21a plug outer periphery inner wall, 21b plug outer periphery upper stage, 21c plug outer periphery outer wall, 22 plug substrate support portion, 22a second substrate support surface, 23 plug bottom portion, 23a plug seat surface, 24 plug hole, 30 cover ring, 30a ring inner wall, 30b ring upper stage, 50 Semiconductor substrate, 51 substrate outer edge region 51, 51a first region, 51b second region, 52 substrate inner region, 53 substrate outer periphery, 53a substrate circular outer periphery, 53b substrate specific outer periphery.

Claims

1. A silicon carbide epitaxial growth apparatus comprising: a substrate mounting member for mounting a semiconductor substrate having a circular outer periphery; and a plug mounted on the substrate mounting member, The substrate mounting member is a mounting member substrate support portion having a first substrate support surface that supports an outer edge region of a back surface of the semiconductor substrate; a mounting member substrate facing portion having a mounting member substrate facing surface facing and spaced apart from a substrate inner region, which is a region inside the outer edge region of the rear surface of the semiconductor substrate; having The plug is a plug substrate support portion having a second substrate support surface which is a surface at the same height as the first substrate support surface, supports a region of the outer edge region of the semiconductor substrate which is not supported by the first substrate support surface, and is continuously connected to the first substrate support surface at both ends of the second substrate support surface; having A silicon carbide epitaxial growth apparatus, wherein the second substrate support surface of the plug supports the outer edge region inside a specific substrate periphery that is a non-circular, specific shaped peripheral portion of the semiconductor substrate.

2. 2. The silicon carbide epitaxial growth apparatus according to claim 1, wherein the substrate mounting member has a plug support surface which is flush with the first substrate support surface and is continuous with the first substrate support surface, and the plug is mounted on the plug support surface.

3. 2. The silicon carbide epitaxial growth apparatus of claim 1, wherein the substrate mounting member further comprises a mounting member plug installation portion on the same plane as the substrate-facing surface of the mounting member, the mounting member being provided in an area where the mounting member substrate support portion is divided in the circumferential direction, and on which the plug is mounted.

4. 4. A silicon carbide epitaxial growth apparatus as described in claim 1, wherein the substrate mounting member further has a mounting member outer circumferential portion on the outer circumferential side of the mounting member substrate support portion, the plug further has a plug outer circumferential portion on the outer circumferential side of the plug substrate support portion, and the top of the upper step of the mounting member outer circumferential portion and the top of the upper step of the plug outer circumferential portion are formed at a height equal to or higher than the surface of the semiconductor substrate mounted on the substrate mounting member.

5. 5. The silicon carbide epitaxial growth apparatus according to claim 4, wherein the upper step of the outer periphery of the mounting member and the upper step of the outer periphery of the plug are inclined in a direction toward the substrate-facing surface of the mounting member.

6. 6. The silicon carbide epitaxial growth apparatus according to claim 4, wherein a hole is provided in an upper stage of the outer periphery of the plug.

7. 7. A silicon carbide epitaxial growth apparatus as described in claim 4, wherein the substrate-facing surface of the mounting member, the inner wall of the outer periphery of the mounting member, the inner wall of the outer periphery of the plug, and the second substrate support surface have a melting point of 1700° C. or higher and are made of a material other than silicon carbide.

8. 8. The silicon carbide epitaxial growth apparatus according to claim 7, characterized in that the material different from silicon carbide is tantalum carbide.

9. 9. The silicon carbide epitaxial growth apparatus according to claim 4, further comprising a cover ring removably mounted on the outer periphery of the mounting member, the uppermost part of which is located higher than the surface of the semiconductor substrate.

10. 10. The silicon carbide epitaxial growth apparatus according to claim 9, wherein the upper stage of the cover ring is located higher in height than the upper stage of the outer periphery of the mounting member and the upper stage of the outer periphery of the plug.

11. 11. A silicon carbide epitaxial growth apparatus as described in claim 9 or claim 10, characterized in that the upper step of the cover ring, the upper step of the outer periphery of the mounting member, and the upper step of the outer periphery of the plug have an inclination in a direction toward the substrate-facing surface of the mounting member.

12. 12. The silicon carbide epitaxial growth apparatus according to claim 9, wherein the cover ring covers an upper portion of an outer periphery of the mounting member.

13. 13. The silicon carbide epitaxial growth apparatus according to claim 9, wherein at least a portion of the cover ring is made of silicon carbide.

14. a plug mounting step of detachably mounting a plug having a second substrate support surface on a substrate mounting member having a first substrate support surface that is the same height as the second substrate support surface and is continuously connected to the second substrate support surface at both ends of the second substrate support surface; a substrate mounting step of supporting an outer peripheral region of a back surface of a semiconductor substrate having a circular outer periphery between the first substrate supporting surface and the second substrate supporting surface, and mounting the semiconductor substrate on the substrate mounting member and the plug such that a substrate inner region, which is a region inside the outer peripheral region of the back surface of the semiconductor substrate, is spaced apart from a substrate facing portion of the substrate mounting member on the inner side of the substrate mounting member; an epitaxial growth step of epitaxially growing silicon carbide on the surface of the semiconductor substrate after the substrate placement step; Equipped with a second substrate support surface of the plug that supports the first substrate and a second substrate support surface of the plug, the second substrate support surface being supported by the second substrate support surface of the plug, and a second outer peripheral portion of the semiconductor substrate that is a non-circular outer peripheral portion of the semiconductor substrate, the second outer peripheral portion being supported by the second substrate support surface of the plug ... and a second outer peripheral portion of the semiconductor substrate that is a non-circular outer peripheral portion of the substrate, the second outer peripheral portion being supported by the second substrate support surface of the plug, and the second outer peripheral portion being supported by the second substrate support surface of the plug.

15. 15. The method for producing a silicon carbide epitaxial substrate according to claim 14, further comprising, after the epitaxial growth step, a recovery step of recovering the semiconductor substrate by lifting up the plug with the semiconductor substrate placed on the second substrate support surface.

16. 16. The method for producing a silicon carbide epitaxial substrate according to claim 14, further comprising a cover ring attachment step of detachably attaching a cover ring to the substrate mounting member prior to the epitaxial growth step.

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