Thin film deposition method, wafer support structure, and vapor phase growth apparatus

Abstract

The present invention provides a film deposition method, a wafer support structure, and a vapor phase growth apparatus that can suppress deterioration of film deposition characteristics. [Solution] The film deposition method of the embodiment is a film deposition method that forms a film on the surface of a wafer using a vapor phase growth apparatus. The film deposition method of the embodiment includes a film deposition process that forms a film on the surface of the wafer. The vapor phase growth apparatus has a susceptor and a plurality of wafer guide parts. The susceptor supports the wafer and is rotated about a rotation axis that extends in the vertical direction. The plurality of wafer guide parts are arranged at intervals in the circumferential direction about the rotation axis, protrude above the susceptor and surround the wafer. The film deposition process includes surrounding the wafer with the plurality of wafer guide parts such that, when viewed in the vertical direction, the direction connecting the rotation axis and each of the wafer guide parts is different from the cleavage direction of the wafer.

Description

Technical Field

[0001] Embodiments of the present invention relate to a film formation method, a wafer support structure, and a vapor deposition apparatus.

Background Art

[0002] A vapor deposition apparatus for forming a film on the surface of a wafer supported from below by a support member is known. In such a vapor deposition apparatus, a wafer guide is disposed around the wafer supported on the support surface. The wafer guide is formed to be equal to or higher than the surface of the wafer so that the wafer does not jump out as the support member rotates. Therefore, in the film formation process of forming a film on the surface of the wafer, the flow of the gas containing the supplied source gas is inhibited by the wafer guide, and the film formation characteristics such as the film thickness at the outermost periphery of the wafer and the carrier concentration distribution may deteriorate.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] The problem to be solved by the present invention is to provide a film formation method, a wafer support structure, and a vapor deposition apparatus that can suppress deterioration of film formation characteristics.

Means for Solving the Problems

[0005] The film deposition method of the embodiment is a film deposition method that forms a film on the surface of a wafer using a vapor phase growth apparatus. The film deposition method of the embodiment includes a film deposition process that forms a film on the surface of the wafer. The vapor phase growth apparatus has a susceptor and a plurality of wafer guide parts. The susceptor supports the wafer and is rotated about a rotation axis that extends in the vertical direction. The plurality of wafer guide parts are arranged at intervals in the circumferential direction about the rotation axis, protrude above the susceptor and surround the wafer. The film deposition process includes surrounding the wafer with the plurality of wafer guide parts such that, when viewed in the vertical direction, the direction connecting the rotation axis and each of the wafer guide parts is different from the cleavage direction of the wafer. [Brief explanation of the drawing]

[0006] [Figure 1] A cross-sectional view showing a vapor phase growth apparatus according to the first embodiment. [Figure 2] A cross-sectional view showing a part of the vapor phase growth apparatus of the first embodiment. [Figure 3] A view from above of a part of the vapor phase growth apparatus of the first embodiment. [Figure 4] A diagram showing the bottom surface of the hexagonal crystal lattice forming the wafer. [Figure 5] A cross-sectional view showing a part of the vapor phase growth apparatus of the first embodiment when wafers are being transported. [Figure 6] A cross-sectional view showing a portion of the susceptor and a portion of the wafer guide portion of the first embodiment. [Figure 7] Section VII-VII in Figure 6. [Figure 8] A diagram showing the crystal orientation of the wafer and the arrangement relationship between the multiple wafer guide sections of the first embodiment. [Figure 9] A diagram showing the arrangement relationship between the measurement points on the wafer after film deposition and the multiple wafer guide sections of the first embodiment. [Figure 10] A block diagram showing a part of the vapor phase growth apparatus of the first embodiment. [Figure 11]A flowchart showing an example of a procedure for forming a film on the surface of a wafer using a vapor phase growth apparatus according to the first embodiment. [Figure 12] A view of the susceptor in the second embodiment from above. [Figure 13] A cross-sectional view showing a portion of the susceptor and a portion of the wafer guide in the second embodiment. [Figure 14] A view of the susceptor in the third embodiment from above. [Figure 15] A diagram showing the crystal orientation of the wafer and the arrangement relationship between it and multiple wafer guide sections of a modified example of the first embodiment. [Modes for carrying out the invention]

[0007] The film deposition method, wafer support structure, and vapor phase growth apparatus of the embodiment will be described below with reference to the drawings. The drawings show the Z-axis, which indicates the vertical direction, as appropriate. The side in which the arrow of the Z-axis points (+Z side) is the upper side in the vertical direction, and the side opposite to the side in which the arrow of the Z-axis points (-Z side) is the lower side in the vertical direction. In the following description, the vertical direction will be referred to as "vertical direction Z," the upper side of vertical direction Z will simply be referred to as "upper side," and the lower side of vertical direction Z will simply be referred to as "lower side." The drawings also show a rotation axis R extending in the vertical direction Z as appropriate. The rotation axis R is a virtual line. In the following description, unless otherwise specified, the radial direction centered on the rotation axis R will simply be referred to as the "radial direction," and the circumferential direction around the rotation axis R will simply be referred to as the "circumferential direction."

[0008] (First embodiment) Figure 1 is a cross-sectional view showing a vapor phase growth apparatus 10 of the first embodiment. Figure 2 is a cross-sectional view showing a part of the vapor phase growth apparatus 10 of the first embodiment. Figure 3 is a view of a part of the vapor phase growth apparatus 10 of the first embodiment from above. In Figure 3, the outline of the wafer W is shown by a dashed line. The vapor phase growth apparatus 10 shown in Figures 1 to 3 is an apparatus for forming a film on the surface of a wafer W. In the vapor phase growth apparatus 10, an epitaxial film is formed on the surface of the wafer W by, for example, the CVD (Chemical Vapor Deposition) method. The film formed on the surface of the wafer W is, for example, a film composed of silicon carbide (SiC), i.e., a SiC film. The film formed on the surface of the wafer W may also be a film composed of other materials such as Si. In the first embodiment, the wafer W is formed of a single crystal having a hexagonal crystal structure. The wafer W is formed of, for example, silicon carbide (SiC). In other words, the wafer W is a SiC substrate. The material used to form the wafer W is, for example, 4H-SiC, 6H-SiC, etc. The wafer W may also be formed from other materials such as silicon (Si).

[0009] As shown in Figure 3, the wafer W is substantially disc-shaped. A portion of the outer edge of the wafer W is an orientation flat portion Wd that extends in a straight line. In other words, in the first embodiment, an orientation flat portion Wd is provided on the outer edge of the wafer W. In the first embodiment, the orientation flat portion Wd extends in one direction of the cleavage direction of the wafer W. The "cleavage direction" is the direction in which the wafer W is prone to cracking, and is determined by the structure of the crystals that make up the wafer W. The cleavage direction of the wafer W is the direction along the cleavage plane formed when the wafer W cracks along the cleavage direction.

[0010] Figure 4 shows the bottom surface of the hexagonal crystal lattice Rw forming the wafer W. As shown in Figure 4, in a hexagonal crystal structure, the direction indicated by the four unit vectors a1, a2, a3, and c, with the center of the bottom surface of the crystal lattice Rw as the origin, is expressed by the Miller index direction index using the smallest integer ratio of the coefficients of each unit vector. Here, the surface of the wafer W is a surface that is approximately aligned with the crystal plane represented by (0001) in the Miller index plane index. In other words, wafer W is a wafer formed from a substrate in which the C plane of the crystal lattice represented by (0001) is approximately aligned with the surface of the wafer W, i.e., a substrate whose orientation is C(0001). Here, the case in which the surface of the wafer W is "approximately" aligned with the crystal plane represented by (0001) includes, for example, the case in which wafer W is an off-angle SiC substrate in which the surface is shifted by a few degrees from the (0001) plane in order to stabilize the crystal structure of the epitaxially grown film. In the SiC with the off-angle, the off-angle is, for example, about 1° to 4°. Vectors a1, a2, and a3 are unit vectors whose directions differ by 120° from each other, and which point from the origin O toward each atom defining the outer perimeter of the bottom surface of the crystal lattice Rw. When the surface of the wafer W is approximately aligned with the crystal plane represented by (0001), vectors a1, a2, and a3 are vectors that are approximately aligned with the surface of the wafer W. The sum of the coefficients of vector a1, a2, and a3 is zero. Vector c is a unit vector that is orthogonal to vectors a1, a2, and a3 and indicates the height direction. When the surface of the wafer W is approximately aligned with the crystal plane represented by (0001), vector c is a vector that is approximately parallel to the thickness direction of the wafer W.

[0011] For example, the crystal orientation shown as [11-20] in Figure 4 indicates that the coefficients of vectors a1, a2, a3, and c are in a ratio of 1:1:-2:0. In Miller indices, negative coefficients are indicated by a bar above the number, but outside of the figure, negative coefficients are indicated by a "-" before the number instead of a bar above the number. Figure 4 shows six crystal orientations: [11-20], [-12-10], [-2110], [-1-120], [1-210], and [2-1-10]. These six crystal orientations are equivalent to each other and are collectively represented as <11-20>. A crystal orientation equivalent to a given crystal orientation is a crystal orientation that, when the crystal is rotated, becomes the same direction as the given crystal orientation and is indistinguishable from it. In the hexagonal crystal system, the crystal orientation represented by <11-20> is the direction in which the crystal is prone to cracking, i.e., the cleavage direction. In the first embodiment, the orientation flat portion Wd extends in the crystal orientation of the wafer W represented by <11-20>. As shown in Figure 3, the portion of the outer edge of the wafer W other than the orientation flat portion Wd is arc-shaped. The wafer W is placed in the vapor phase growth apparatus 10 with the surface Wa on which the film is formed facing upwards and the back surface Wb on the opposite side of the surface Wa facing downwards. Even if the wafer W is the SiC substrate with the off-angle described above, the direction of <11-20> when viewed in the thickness direction of the wafer W is the same as, or almost the same as, when the wafer W is a SiC substrate with an off-angle of 0°.

[0012] As shown in Figure 1, the vapor phase growth apparatus 10 comprises a chamber 20, a supply pipe 24, a susceptor 30, a wafer guide section 40, a first heating section 51, a second heating section 52, a third heating section 53, and a drive section 60. The susceptor 30 and the wafer guide section 40 constitute a wafer support structure 70.

[0013] The chamber 20 houses therein a supply pipe 24, a susceptor 30, a wafer guide part 40, a first heating part 51, a second heating part 52, a third heating part 53, and a drive part 60. The chamber 20 is made of a metal such as stainless steel (SUS), for example. The chamber 20 has a cylindrical shape extending in the vertical direction Z. A supply port 21 is formed in the top plate of the chamber 20. A discharge port 22 is formed in the bottom of the chamber 20. A gas G containing a source gas for forming a film on the wafer W is supplied from the supply port 21 into the chamber 20.

[0014] The supply pipe 24 has a cylindrical shape extending in the vertical direction Z. The supply pipe 24 is open at both the upper and lower sides. The gas G supplied into the chamber 20 from the supply port 21 flows downward inside the supply pipe 24. The gas G flowing downward inside the supply pipe 24 is supplied to the wafer W placed on the susceptor 30. The excess gas G among the gas G supplied into the chamber 20 is discharged to the outside of the chamber 20 from the discharge port 22.

[0015] An epitaxial film is formed on the surface of the wafer W by the reaction of the source gas contained in the gas G on the surface of the wafer W. The source gas is, for example, a gas containing a Si-based gas and a C-based gas. The Si-based gas is, for example, silane (SiH4), dichlorosilane (SiH2Cl2), trichlorosilane (SiHCl3), tetrachlorosilane (SiCl4), etc. The C-based gas is, for example, propane (C3H8), etc. In the first embodiment, the source gas is, for example, a gas containing silane (SiH4) and propane (C3H8).

[0016] In the first embodiment, other gases used in addition to the raw material gas are also supplied into the chamber 20 from the supply port 21. Examples of these gases include impurity gas, carrier gas, and hydrogen chloride (HCl) gas. Examples of impurity gases include N-type impurity gases such as nitrogen and P-type impurity gases such as TMA (trimethylaluminum). The carrier gas is, for example, argon gas or hydrogen gas. More specifically, the carrier gas when the wafer W is brought into the vapor phase growth apparatus 10 and placed on the susceptor 30, and when the wafer W after film formation is removed from the susceptor 30 and transported out of the vapor phase growth apparatus 10, is argon gas. The carrier gas during film formation is hydrogen gas.

[0017] The susceptor 30 is a support member that supports the wafer W from below on its support surface 30a. The susceptor 30 is supported from below by the drive unit 60. As shown in Figure 2, the susceptor 30 has a base 31 and a movable part 32. The base 31 and the movable part 32 are separate components. The base 31 and the movable part 32 are made of, for example, poly-SiC. The base 31 and the movable part 32 may also be made of graphite. In this case, a coating layer made of SiC may be provided on each surface of the base 31 and the movable part 32.

[0018] In the first embodiment, the base 31 is annular in shape surrounding the axis of rotation R. The base 31 has a support surface 30a that supports the wafer W. The outermost radial position of the support surface 30a is radially inward from the outer circumference of the wafer W. The support surface 30a supports the wafer W from below at a position radially inward from the outer circumference of the wafer.

[0019] The base portion 31 has an inner annular portion 33 and a guide support portion 35. As shown in Figure 3, the inner annular portion 33 is an annular shape surrounding the axis of rotation R. In the first embodiment, the radial inner edge of the inner annular portion 33 is the radial inner edge of the base portion 31.

[0020] The guide support portion 35 is located radially outward from the inner annular portion 33. In the first embodiment, the guide support portion 35 is an annular shape surrounding the axis of rotation R. More specifically, the guide support portion 35 is substantially annular with respect to the axis of rotation R. The guide support portion 35 is the part that supports the wafer guide portion 40 from below. The guide support portion 35 is located radially outward from the support surface 30a. The upper surface 36 of the guide support portion 35 is located below the support surface 30a. The upper surface 36 and the support surface 30a are connected radially by a bevel 37. The bevel 37 is located radially outward from the radially outward side of the support surface 30a, and as it moves radially outward, it moves downward and connects to the radially inward side of the upper surface 36.

[0021] As shown in Figure 2, in the first embodiment, the radial inner edge of the guide support portion 35 is connected to the radial outer edge of the inner annular portion 33. The upper surface 36 of the guide support portion 35 is located above the upper surface of the inner annular portion 33.

[0022] The movable part 32 is positioned radially inward of the inner annular portion 33 of the base 31. The movable part 32 is fitted radially inward of the inner annular portion 33 of the base 31. When the wafer W is placed on the susceptor 30, the back surface Wb of the wafer W is positioned above the upper surface of the inner annular portion 33 and the upper surface of the movable part 32. A gap is provided between the wafer W and the inner annular portion 33 in the vertical direction Z, and between the wafer W and the movable part 32 in the vertical direction Z.

[0023] The movable part 32 is movable in the vertical direction Z. Figure 5 is a cross-sectional view showing a part of the vapor phase growth apparatus 10 when a wafer W is being transported. As shown in Figure 5, when the wafer W is being transported, the movable part 32 is moved above the inner annular part 33. In the first embodiment, the movable part 32 is moved in the vertical direction Z by the lifting unit 80. The lifting unit 80 has a plurality of movable pins 81 located below the movable part 32. The lifting unit 80 moves the plurality of movable pins 81 upward, and the movable part 32 is moved upward by the plurality of movable pins 81 pushing the movable part 32 from below to above. The plurality of movable pins 81 move above the second heating unit 52 through a gap provided in the second heating unit 52, pushing the movable part 32 upward.

[0024] When the wafer W is transported onto the susceptor 30, the wafer W transported by the transport unit 100 is placed on the movable unit 32, which is located above the inner annular unit 33. In this state, when the movable unit 32 is moved downward by the lifting unit 80, the radially outer portion of the wafer W is placed on the susceptor 30. When the wafer W is transported off the susceptor 30, the movable unit 32 rises, and the wafer W is lifted above the wafer guide unit 40 by the movable unit 32. In this state, the wafer W is transported off the movable unit 32 by the transport unit 100.

[0025] As shown in Figure 3, the base portion 31 has a plurality of fixing holes 35a that open upward. The plurality of fixing holes 35a are spaced apart in the circumferential direction. In the first embodiment, the plurality of fixing holes 35a are spaced equally apart around the circumference. In the first embodiment, there are six plurality of fixing holes 35a. In the first embodiment, the fixing holes 35a are circular holes when viewed in the vertical direction Z. The plurality of fixing holes 35a have the same diameter and radial position. The diameter of the inscribed circle 35b of the plurality of fixing holes 35a centered on the rotation axis R is larger than the diameter of the wafer W. In the first embodiment, the radially inner position of the plurality of fixing holes 35a is radially outer of the outer circumference of the wafer W.

[0026] Figure 6 is a cross-sectional view showing a portion of the susceptor 30 and a portion of the wafer guide portion 40. As shown in Figure 6, the fixing hole portion 35a is recessed downward from the upper surface of the guide support portion 35. The fixing hole portion 35a is a hole with a bottom on the lower side. The fixing hole portion 35a may also be a hole that penetrates the base portion 31 in the vertical direction Z.

[0027] Multiple wafer guide portions 40 are supported from below by a susceptor 30. Multiple wafer guide portions 40 surround the outer edge of the wafer W from the radial outside. Multiple wafer guide portions 40 are arranged at intervals in the circumferential direction around the rotation axis R. In the first embodiment, multiple wafer guide portions 40 are arranged at equal intervals around the entire circumference. The arrangement of multiple wafer guide portions 40 does not have to be at equal intervals. In the first embodiment, there are six multiple wafer guide portions 40. The wafer guide portions 40 are made of, for example, poly-SiC. The wafer guide portions 40 may also be made of graphite. In this case, a coating layer made of SiC may be provided on the surface of the wafer guide portion 40.

[0028] As shown in Figure 6, in the first embodiment, the plurality of wafer guide portions 40 are columnar in shape and extend in the vertical direction Z. As shown in Figure 3, the wafer guide portion 40 is circular when viewed in the vertical direction Z. The plurality of wafer guide portions 40 are cylindrical in shape and extend in the vertical direction Z. The plurality of wafer guide portions 40 are each fixed inside the plurality of fixing holes 35a. In the first embodiment, the lower portion of each wafer guide portion 40 is fixed inside each fixing hole 35a. Each wafer guide portion 40 is fixed inside each fixing hole 35a, for example, by press-fitting. The plurality of wafer guide portions 40 each protrude upward from inside the plurality of fixing holes 35a. That is, the upper end of each wafer guide portion 40 is located above the upper end of each fixing hole 35a.

[0029] One of the multiple wafer guide portions 40 is equipped with an indicator. As shown in Figure 3, in the first embodiment, the wafer guide portion 40 (hereinafter referred to as wafer guide portion 40M) facing the orientation flat portion Wd in the radial direction has a mark portion M as an indicator. In the first embodiment, the mark portion M is, for example, a groove recessed in the upper surface of the wafer guide portion 40. The direction in which the groove extends is formed parallel to the orientation flat portion Wd. In addition to a groove, the mark portion M may also be a rib that protrudes upward from the upper surface of the wafer guide portion 40 and extends parallel to the orientation flat portion Wd.

[0030] The marked portion M indicates a predetermined direction along which the orientation flat portion Wd, provided on the outer edge of the wafer W, should be aligned when supporting the wafer W on the support surface 30a. The predetermined direction is perpendicular to the vertical direction Z. In Figure 3, the predetermined direction is the left-right direction in Figure 3, and is indicated by arrow D. In the following explanation, the predetermined direction indicated by the marked portion M will be referred to as "predetermined direction D".

[0031] Each of the multiple wafer guide portions 40 has a main body portion 40a and a protruding portion 40b. The main body portion 40a is columnar in shape extending in the vertical direction Z. Figure 7 is a cross-sectional view of the wafer guide portion 40, which is a cross-sectional view taken along line VII-VII in Figure 6. As shown in Figure 7, in the first embodiment, the main body portion 40a is cylindrical in shape extending in the vertical direction Z with respect to the central axis J. The central axis J is a virtual line extending in the vertical direction Z. The outer diameter of the main body portion 40a is smaller than the inner diameter of the fixing hole portion 35a. The outer circumferential surface of the main body portion 40a is positioned away from the inner surface of the fixing hole portion 35a. As shown in Figure 6, the lower surface of the main body portion 40a is in contact with the bottom surface of the fixing hole portion 35a. The lower surface of the main body portion 40a is, for example, a plane perpendicular to the vertical direction Z. The upper surface of the main body portion 40a is, for example, a plane perpendicular to the vertical direction Z.

[0032] The upper surface of the main body portion 40a may, for example, be an arc shape that is convex upward in a cross-section including the central axis J. In other words, the upper end of the main body portion 40a may, for example, be a hemispherical shape that is convex upward. Alternatively, the upper end of the main body portion 40a may be a cone shape that is convex upward, or a pyramidal shape that is convex upward. The radially inner upper surface of the main body portion 40a is preferably inclined downward as it moves inward in the radial direction. In the first embodiment, the upper surface of the main body portion 40a is provided with a chamfered portion 40c centered on the central axis J at the intersection with the outer circumferential surface of the main body portion 40a. The chamfered portion 40c facing inward in the radial direction of the rotation axis R is inclined downward as it moves inward in the radial direction. By providing a chamfered portion 40c on the upper side of the main body portion 40a, even if the wafer W placed on the movable portion 32 rides up onto the main body portion 40a when being transported onto the susceptor 30, the wafer W can be smoothly guided along the chamfered portion 40c to the support surface 30a.

[0033] The protrusion 40b is provided on the outer circumferential surface of the main body 40a. The outer circumferential surface of the main body 40a is the outer surface in the radial direction centered on the central axis J of the entire exposed surface of the main body 40a. In the following description, the radial direction centered on the central axis J may be referred to as the "second radial direction". The protrusion 40b projects outward in the second radial direction from the outer circumferential surface of the main body 40a. As shown in Figure 7, in the first embodiment, the outer surface of the protrusion 40b in the second radial direction is an arc shape that is convex outward in the second radial direction in a cross section perpendicular to the vertical direction Z. In the first embodiment, the protrusion 40b is a semicircle shape that is convex outward in the second radial direction in a cross section perpendicular to the vertical direction Z. As shown in Figure 6, in the first embodiment, the protrusion 40b is a rib extending in the vertical direction Z. The upper end of the protrusion 40b is located below the upper end of the main body 40a. The lower end of the protrusion 40b is flush with the lower end of the main body 40a. The lower portion of the protrusion 40b is located inside the fixing hole 35a. The upper portion of the protrusion 40b is located above the fixing hole 35a.

[0034] As shown in Figure 7, the protrusions 40b contact the inner surface (inner circumferential surface) of the fixing hole 35a that is opposite to the outer circumferential surface of the main body portion 40a located inside the fixing hole portion 35a. More specifically, the second radially outer end of the portion of the protrusions 40b located inside the fixing hole portion 35a contacts the inner surface of the fixing hole portion 35a. Multiple protrusions 40b are provided at intervals in the circumferential direction around the central axis J. The multiple protrusions 40b are arranged at equal intervals over a full circumference in the circumferential direction around the central axis J. In the first embodiment, the number of multiple protrusions 40b is four. In the first embodiment, the multiple protrusions 40b deform in the second radial direction when the wafer guide portion 40 is press-fitted into the fixing hole portion 35a. The multiple protrusions 40b are, for example, in a state of elastic deformation in the second radial direction inside the fixing hole portion 35a.

[0035] In each of the multiple wafer guide portions 40, at least a portion of the outer circumferential surface of the portion of the wafer guide portion 40 located inside the fixed hole portion 35a is positioned away from the inner surface of the fixed hole portion 35a. The outer circumferential surface of the portion of the wafer guide portion 40 located inside the fixed hole portion 35a includes the outer circumferential surface of the portion of the main body portion 40a located inside the fixed hole portion 35a and the second radially outer surface of the portion of the multiple protrusions 40b located inside the fixed hole portion 35a. In the first embodiment, the second radially outer ends of the multiple protrusions 40b are in contact with the inner surface of the fixed hole portion 35a. The portions of the wafer guide portion 40 located inside the fixed hole portion 35a, other than the second radially outer ends of the multiple protrusions 40b, are positioned away from the inner surface of the fixed hole portion 35a in the second radial direction. Therefore, a gap S is provided between the outer circumferential surface of the wafer guide portion 40 and the inner surface of the fixed hole portion 35a. In the first embodiment, the gap S is a gas-filled void.

[0036] Figure 8 is a view from above of a wafer W surrounded by multiple wafer guide sections 40, and shows the relationship between the crystal orientation of the wafer W and the arrangement of the multiple wafer guide sections 40. In Figure 8, the crystal orientations of the wafer W, represented by <11-20>, are indicated by dashed arrows. As shown in Figure 8, when viewed in the vertical direction Z, the direction connecting the rotation axis R and each wafer guide section 40 is different from the crystal orientation of the wafer W, represented by <11-20>. In other words, when viewed in the vertical direction Z, the direction connecting the rotation axis R and each wafer guide section 40 is different from the cleavage direction of the wafer W.

[0037] In Figure 8, the direction connecting the rotation axis R and each wafer guide portion 40 is indicated by a dashed line passing through the rotation axis R and the central axis J of each wafer guide portion 40 when viewed in the vertical direction Z. Preferably, the direction connecting the rotation axis R and each wafer guide portion 40 is offset by 5° or more with respect to the cleavage direction of the wafer W. More preferably, the direction connecting the rotation axis R and each wafer guide portion 40 is offset by 10° or more with respect to the cleavage direction of the wafer W. Even more preferably, the direction connecting the rotation axis R and each wafer guide portion 40 is offset by 15° or more with respect to the cleavage direction of the wafer W.

[0038] In this specification, "a certain direction is different from another direction" means that a certain direction is not parallel to another direction. In other words, "the direction connecting the rotation axis R and the wafer guide portion 40 is different from the cleavage direction of the wafer W" means that the direction connecting the rotation axis R and the wafer guide portion 40 is not parallel to the cleavage direction of the wafer W.

[0039] When viewed in the vertical direction Z, the direction connecting the rotation axis R and each wafer guide portion 40 is different from the predetermined direction D indicated by the mark portion M. When viewed in the vertical direction Z, the direction connecting the rotation axis R and each wafer guide portion 40 is different from the direction tilted 60° with respect to the predetermined direction D. In Figure 8, the predetermined direction D is the crystal orientation represented by [-12-10] and [1-210]. The direction tilted 60° with respect to the predetermined direction D is the crystal orientation represented by [-2110], [-1-120], [2-1-10], and [11-20].

[0040] Figure 9 is a view from above of a wafer W supported by multiple wafer guides 40, and shows the arrangement relationship between the measurement points on the wafer W after film deposition and the multiple wafer guides 40. The lines L1a and L1b shown in Figure 9 are imaginary lines extending in a direction perpendicular to the vertical direction Z. Line L1a is a line that, when viewed in the vertical direction Z, passes through the rotation axis R and extends in a predetermined direction D indicated by the mark M. Line L1b is a line that, when viewed in the vertical direction Z, passes through the rotation axis R and extends in a direction perpendicular to the predetermined direction D. When viewed in the vertical direction Z, the multiple wafer guides 40 are positioned at different locations on the line L1a that passes through the rotation axis R and extends in a predetermined direction D. When viewed in the vertical direction Z, the multiple wafer guides 40 are positioned at different locations on the line L1b that passes through the rotation axis R and extends in a direction perpendicular to the predetermined direction D. When viewed in the vertical direction Z, the multiple wafer guide portions 40 are preferably arranged at a distance of 5 mm or more from the straight lines L1a and L1b, and more preferably at a distance of 10 mm or more.

[0041] As shown in Figure 1, the drive unit 60 rotates the susceptor 30 around a rotation axis R extending in the vertical direction Z. The drive unit 60 includes a susceptor holding unit 61 and a power unit 62. The susceptor holding unit 61 is cylindrical with an opening on the upper side. The susceptor 30 is held at the upper end of the susceptor holding unit 61. The susceptor holding unit 61 is located inside the chamber 20. The susceptor holding unit 61 constitutes the wafer support structure 70. The lower end of the susceptor holding unit 61 is located outside the chamber 20 through a hole formed in the bottom of the chamber 20. The power unit 62 rotates the susceptor holding unit 61 around the rotation axis R. The power unit 62 is, for example, a motor. The power unit 62 is connected to the lower end of the susceptor holding unit 61. The power unit 62 may include a motor and a reduction mechanism connected to the motor. In this case, the motor's rotation is transmitted to the susceptor holding unit 61 via the reduction mechanism. The power unit 62 is located, for example, outside the chamber 20.

[0042] The first heating section 51 and the second heating section 52 are heating sections capable of heating the susceptor 30. When the susceptor 30 is heated by the first heating section 51 and the second heating section 52, the wafer W and the wafer guide section 40 in contact with the susceptor 30 are heated. As shown in Figure 2, in the first embodiment, the first heating section 51 and the second heating section 52 are located below the susceptor 30. The first heating section 51 and the second heating section 52 heat the susceptor 30 by applying heat H to the susceptor 30 from below. The first heating section 51 and the second heating section 52 are located inside the susceptor holding section 61 in the drive section 60. The first heating section 51 and the second heating section 52 are resistance heating type heaters. The first heating section 51 and the second heating section 52 are, for example, composed of electric heating wires extending along a plane perpendicular to the vertical direction Z. The first heating section 51 and the second heating section 52 may have any structure as long as they are capable of heating the target object.

[0043] The first heating section 51 is located radially outward from the second heating section 52. The first heating section 51 surrounds the second heating section 52 from the radially outward direction. The first heating section 51 is located below the wafer guide section 40 and the guide support section 35. At least a portion of the first heating section 51 overlaps with the wafer guide section 40 when viewed in the vertical direction Z.

[0044] The second heating section 52 is located radially inward of the first heating section 51. The second heating section 52 has a portion located below the inner annular section 33 and a portion located below the movable section 32. The radial outer edge of the second heating section 52 is located below the inner annular section 33. The portion of the second heating section 52 that is located radially inward of the portion located below the inner annular section 33 is located below the movable section 32.

[0045] As shown in Figure 1, the third heating section 53 is annular in shape surrounding the supply pipe 24. In the first embodiment, the vapor phase growth apparatus 10 includes three third heating sections 53. The three third heating sections 53 are spaced apart in the vertical direction Z. Each third heating section 53 heats the gas G passing through the inside of the supply pipe 24. This increases the temperature of the gas G when it reaches the wafer W. Therefore, the deposition rate of the SiC film formed on the surface of the wafer W can be increased. The number of third heating sections 53 in the vapor phase growth apparatus 10 may be two or fewer, or four or more. The third heating section 53 is, for example, a resistance heating type heater composed of an electric heating wire. The third heating section 53 may have any structure as long as it can heat the target.

[0046] Figure 10 is a block diagram showing a part of the vapor phase growth apparatus 10. As shown in Figure 10, the vapor phase growth apparatus 10 includes a control unit 90. The control unit 90 controls each part of the vapor phase growth apparatus 10. The control unit 90 controls the first heating unit 51, the second heating unit 52, the third heating unit 53, the drive unit 60, the lifting unit 80, and the transport unit 100.

[0047] Figure 11 is a flowchart showing an example of a procedure for a film deposition method using a vapor phase growth apparatus 10 to form a film on the surface of a wafer W. As shown in Figure 11, the control unit 90 places the wafer W on the susceptor 30 (step S110). In step S110, the control unit 90 transports the wafer W using the transport unit 100 and places the wafer W on the movable unit 32, which has been moved to the upper side as shown in Figure 5. The control unit 90 controls the lifting unit 80 to move the movable unit 32 downward and places the wafer W on the movable unit 32 onto the support surface 30a. Thus, the wafer W is placed on the susceptor 30. When placing the wafer W onto the support surface 30a, even if the wafer W rides up onto the wafer guide unit 40, the wafer W that has ridden up can be smoothly guided to the support surface 30a along the chamfered portion 40c of the main body unit 40a.

[0048] In step S110, the control unit 90 detects the orientation flat portion Wd of the wafer W using the transport unit 100, and places the wafer W on the movable unit 32 such that the direction in which the orientation flat portion Wd extends is aligned with a predetermined direction D indicated by the direction in which the groove of the mark portion M of the wafer guide portion 40 extends. In other words, in the film deposition method of the first embodiment, the film deposition process includes aligning the orientation flat portion Wd with the predetermined direction D. As a result, the plurality of wafer guide portions 40 and the wafer W surrounded by the plurality of wafer guide portions 40 are arranged in the configuration shown in Figures 3, 8, and 9. Therefore, when viewed in the vertical direction Z, the direction connecting the rotation axis R and each wafer guide portion 40 is different from the cleavage direction of the wafer W, i.e., the crystal orientation of the wafer W represented by <11-20>.

[0049] As shown in Figure 11, after the wafer W is placed on the susceptor 30, the control unit 90 performs a film deposition process to form a film on the surface of the wafer W (step S120). In other words, the film deposition method in the first embodiment includes a film deposition process to form a film on the surface of the wafer W. The film deposition process is performed with the wafer W surrounded by a plurality of wafer guide parts 40 in the same arrangement as when the wafer W was placed in step S110. In other words, in the film deposition method of the first embodiment, the film deposition process includes surrounding the wafer W with a plurality of wafer guide parts 40 such that, when viewed in the vertical direction Z, the direction connecting the rotation axis R and each wafer guide part 40 is different from the cleavage direction of the wafer W. The film deposition process includes surrounding the wafer W with a plurality of wafer guide parts 40 such that, when viewed in the vertical direction Z, the direction connecting the rotation axis R and each wafer guide part 40 is different from the crystal orientation of the wafer W represented by <11-20>.

[0050] During the film deposition process, the control unit 90 rotates the wafer W around the rotation axis R (step S121) and heats the wafer W (step S122). During the film deposition process, the control unit 90 rotates the wafer W around the rotation axis R by rotating the susceptor 30 around the rotation axis R using the drive unit 60. During the film deposition process, the control unit 90 heats the wafer W by heating the susceptor 30 with the first heating unit 51 and the second heating unit 52. The rotation and heating of the wafer W are carried out until the film deposition process is completed.

[0051] In the film deposition process, the control unit 90 controls the temperature of the wafer W (step S123). In step S123, the control unit 90 measures the temperature of the wafer W using a temperature sensor (not shown). In step S123, the control unit 90 controls the first heating unit 51 and the second heating unit 52 based on the measurement result of the temperature sensor (not shown). The control unit 90 controls the first heating unit 51 and the second heating unit 52 so that the temperature of the wafer W measured by the temperature sensor (not shown) is, for example, 1500°C or higher and 1650°C or lower.

[0052] In the film deposition process, the control unit 90 introduces gas G containing the raw material gas into the chamber 20 from the supply port 21 and supplies the gas G to the wafer W (step S124). By supplying the raw material gas to the heated surface Wa of the wafer W, a SiC film is formed on the surface Wa of the wafer W. By continuing to supply the raw material gas to the wafer W for a predetermined time, a SiC film of the desired thickness is formed on the surface Wa of the wafer W. By rotating the wafer W around the rotation axis R by the drive unit 60 while supplying the raw material gas to the surface Wa of the wafer W, the amount of raw material gas supplied and variations in the raw material gas within the plane of the surface Wa of the wafer W can be reduced. Therefore, the uniformity of the thickness of the film formed on the wafer W can be improved. In the film deposition process, the control unit 90 heats the gas G in the supply pipe 24 with the third heating unit 53. When the film deposition process is completed, the control unit 90 stops the drive unit 60 and each heating unit, and stops the supply of gas G into the chamber 20.

[0053] The step S123 described above, which controls the temperature of the wafer W, is performed continuously, for example, during the film deposition process. Step S123 may be performed at predetermined intervals. Step S121, which rotates the wafer W, may be started after the wafer W has been heated to a predetermined temperature and before the gas G is supplied.

[0054] After the film deposition process is completed, the control unit 90 removes the wafer W from the vapor phase growth apparatus 10 (step S130). In step S130, the control unit 90 raises the movable part 32 using the lifting unit 80 to lift the wafer W. The control unit 90 then transports the lifted wafer W using the transport unit 100.

[0055] According to the first embodiment, the vapor phase growth apparatus 10 used in the film deposition method comprises a susceptor 30 that supports a wafer W and a plurality of wafer guide portions 40 that surround the wafer W. The wafer guide portions 40 are arranged at intervals in the circumferential direction around the rotation axis R and protrude above the susceptor 30. In this way, since the plurality of wafer guide portions 40 are arranged at intervals in the circumferential direction, the supplied raw material gas can flow between the wafer guide portions 40 that are circumferentially away from the surface Wa of the wafer W. Therefore, compared to the case where the wafer guide portions 40 are annular, obstruction of the flow of the raw material gas can be suppressed. As a result, the film thickness and carrier concentration of the film formed on the outer periphery of the wafer W differ significantly from the film thickness and carrier concentration of the film formed on the central part of the wafer W, which can suppress deterioration of film deposition characteristics.

[0056] According to the first embodiment, when viewed in the vertical direction Z, the direction connecting the rotation axis R and each wafer guide portion 40 is different from the cleavage direction of the wafer W. In other words, in a film deposition method for forming a film on the surface of a wafer W using a vapor phase growth apparatus 10, the film deposition process includes surrounding the wafer W with a plurality of wafer guide portions 40 such that when viewed in the vertical direction Z, the direction connecting the rotation axis R and each wafer guide portion 40 is different from the cleavage direction of the wafer W. Therefore, when the wafer W rotates and shifts radially outward, it comes into contact with the wafer guide 40, preventing the wafer W from shifting from the desired position on the susceptor. In this case, if the line connecting the rotation axis R and the wafer guide 40 is in the same direction as the cleavage direction, cleavage is likely to occur. To prevent this, by arranging the wafer guides 40 so that the directions of the two do not coincide, the direction in which the stress generated in the wafer W due to contact with each wafer guide portion 40 acts can be shifted relative to the cleavage direction in which the wafer W is prone to cracking. This makes it possible to suppress the cracking of the wafer W surrounded by the multiple wafer guide portions 40 during the film deposition process, and to prevent the formation of crystal defects, i.e., dislocations, in the wafer W due to stress. The effect of suppressing wafer W cracking is preferably obtained when the angle in which the direction connecting the rotation axis R and each wafer guide portion 40 is deviated from the cleavage direction of the wafer W, as viewed in the vertical direction Z, is 5° or more, more preferably when it is 10° or more, and even more preferably when it is 15° or more. Note that the effect of suppressing wafer W cracking can be obtained if the angle in which the direction connecting the rotation axis R and each wafer guide portion 40 is deviated from the cleavage direction of the wafer W, as viewed in the vertical direction Z, is greater than 0°.

[0057] According to the first embodiment, the wafer W is formed from a single crystal having a hexagonal crystal structure. When viewed in the vertical direction Z, the direction connecting the rotation axis R and each wafer guide portion 40 is different from the crystal orientation of the wafer W represented by <11-20>. In other words, the film deposition process includes surrounding the wafer W with a plurality of wafer guide portions 40 such that when viewed in the vertical direction Z, the direction connecting the rotation axis R and each wafer guide portion 40 is different from the crystal orientation of the wafer W represented by <11-20>. Therefore, the direction in which stress acts on the wafer W due to contact with each wafer guide portion 40 can be made different from the cleavage direction of the wafer W formed from a single crystal having a hexagonal crystal structure. This makes it possible to suppress cracking of the wafer W formed from a single crystal having a hexagonal crystal structure.

[0058] According to the first embodiment, the wafer guide portion 40M includes a mark portion M which is an indicator showing a predetermined direction D perpendicular to the vertical direction Z. When viewed in the vertical direction Z, the direction connecting the rotation axis R and each wafer guide portion 40 is different from the predetermined direction D, and also different from the direction tilted 60° with respect to the predetermined direction D. The wafer W is a SiC substrate. The surface of the wafer W is a surface along the crystal plane represented by (0001). An orientation flat portion Wd extending in the crystal orientation of the wafer W represented by <11-20> is provided on the outer edge of the wafer W. The film deposition process includes aligning the orientation flat portion Wd along the predetermined direction D. Therefore, as shown in Figure 8, the cleavage direction of the wafer W is the direction in which the orientation flat portion Wd extends, and the direction tilted 60° each with respect to the direction in which the orientation flat portion Wd extends. Therefore, each wafer guide portion 40 is positioned such that the direction connecting the rotation axis R and each wafer guide portion 40, when viewed in the vertical direction Z, is different from both the predetermined direction D indicated by the mark portion M and the direction inclined 60° with respect to the predetermined direction D. The orientation flat portion Wd is aligned with the predetermined direction D, and the wafer W is surrounded by multiple wafer guide portions 40. This makes it possible to make the direction connecting the rotation axis R and each wafer guide portion 40, when viewed in the vertical direction Z, different from the cleavage direction of the wafer W having a hexagonal crystal structure. Consequently, it is possible to suppress cracking of the wafer W, which is formed from a single crystal having a hexagonal crystal structure, during the film deposition process.

[0059] For example, when measuring the thickness and carrier concentration of a film formed on the surface of a wafer W to confirm its quality, the film thickness and carrier concentration are measured at multiple locations along a straight line extending perpendicular to the wafer thickness direction, passing through the center Cw of the roughly disc-shaped wafer W. The direction in which the measurement is performed is determined, for example, based on the direction in which multiple semiconductor elements are arranged on the wafer W. As shown by the dashed line in Figure 9, in a wafer W provided with an orientation flat Wd, semiconductor elements are formed in multiple element formation regions We that are arranged in a matrix in the direction in which the orientation flat Wd extends and in a direction perpendicular to the direction in which the orientation flat Wd extends. Therefore, film measurements are often performed at locations on the wafer W located on measurement lines ML1a and ML1b that extend in the two directions in which the multiple element formation regions We are arranged. Measurement line ML1a is a straight line that, when viewed in the thickness direction of the wafer W, passes through the center Cw of the wafer W and extends in the direction in which the orientation flat Wd extends. The measurement line ML1b is a straight line that, when viewed in the thickness direction of the wafer W, passes through the center Cw of the wafer W and extends in a direction perpendicular to the direction in which the orientation flat portion Wd extends. During the film deposition process, the temperature of the wafer W in contact with multiple wafer guide portions 40 tends to be higher than that of other parts of the wafer W. Therefore, the film thickness and carrier concentration in the areas of the wafer W in contact with multiple wafer guide portions 40 tend to deviate from the average values. Consequently, the areas of the wafer W in contact with multiple wafer guide portions 40 may not be used in the manufacture of semiconductor devices. In such cases, it may not be desirable to measure the film on parts of the wafer W that are not used in the manufacture of semiconductor devices.

[0060] In the case described above, according to the first embodiment, when viewed in the vertical direction Z, the multiple wafer guide portions 40 are positioned at locations different from the straight line L1a that passes through the rotation axis R and extends in a predetermined direction D, and also different from the straight line L1b that passes through the rotation axis R and extends in a direction perpendicular to the predetermined direction D. The center Cw of the wafer W is aligned with the rotation axis R, and when viewed in the vertical direction Z, the straight lines L1a and L1b coincide with the measurement lines ML1a and ML1b used when measuring the film on the wafer W, respectively. That is, when viewed in the vertical direction Z, the straight line L1a coincides with the measurement line ML1a that passes through the center Cw of the wafer W and extends in the direction in which the orientation flat portion Wd extends. When viewed in the vertical direction Z, the straight line L1b coincides with the measurement line ML1b that passes through the center Cw of the wafer W and extends in a direction perpendicular to the direction in which the orientation flat portion Wd extends. Since the multiple wafer guide sections 40 are positioned at different locations from the straight lines L1a and L1b when viewed in the vertical direction Z, during the film deposition process, the wafer W is surrounded by the multiple wafer guide sections 40 at locations different from the measurement points on the measurement lines ML1a and ML1b that are measured after film deposition. As a result, the measurement of film thickness and carrier concentration in the portion of the wafer W surrounded by the multiple wafer guide sections 40 during the film deposition process is suppressed.

[0061] Furthermore, the effect of suppressing the measurement of film thickness and carrier concentration in the portion of the wafer W that is far from the portion surrounded by the multiple wafer guide portions 40 during the film deposition process is preferably obtained when the multiple wafer guide portions 40 are arranged at a distance of 5 mm or more from the straight lines L1a and L1b when viewed in the vertical direction Z, and more preferably obtained when they are arranged at a distance of 10 mm or more from the straight lines L1a and L1b.

[0062] According to the first embodiment, the susceptor 30 includes a base portion 31. The base portion 31 has a plurality of fixing holes 35a that open upward and are spaced apart in the circumferential direction. The plurality of wafer guide portions 40 are each fixed inside the plurality of fixing holes 35a and each protrudes upward from inside the plurality of fixing holes 35a. Therefore, compared to the case where the base portion 31 and the plurality of wafer guide portions 40 are integrally molded, heat can be less easily transferred from the base portion 31 to each wafer guide portion 40. Consequently, it is possible to suppress the temperature of the portion of the outer periphery of the wafer W that is in contact with each wafer guide portion 40 from rising. Consequently, it is possible to suppress the temperature of the outer periphery of the wafer W from rising compared to the central portion of the wafer W during the film deposition process. Consequently, it is possible to further suppress the significant difference between the film thickness and carrier concentration of the film formed on the outer periphery of the wafer W and the film thickness and carrier concentration of the film formed on the central portion of the wafer W. Consequently, it is possible to further suppress the deterioration of film deposition characteristics such as the in-wafer plane distribution of the film formed on the wafer W in the outer periphery of the wafer W. This makes it possible to further reduce the portion of the wafer W that cannot be used as a region for forming semiconductor elements after film deposition. Therefore, it is possible to further suppress the decrease in yield of semiconductor devices manufactured using the wafer W.

[0063] According to the first embodiment, in each of the plurality of wafer guide portions 40, at least a portion of the outer circumferential surface of the portion of the wafer guide portion 40 located inside the fixing hole portion 35a is positioned away from the inner surface of the fixing hole portion 35a. Therefore, heat is less likely to be transferred from the base portion 31 to each wafer guide portion 40 compared to the case where the entire outer circumferential surface of each wafer guide portion 40 is in contact with the inner surface of each fixing hole portion 35a. Consequently, the temperature of the portion of the wafer W that is in contact with the plurality of wafer guide portions 40 can be further suppressed.

[0064] According to the first embodiment, each of the plurality of wafer guide portions 40 has a main body portion 40a extending in the vertical direction Z, and a protrusion 40b provided on the outer circumferential surface of the main body portion 40a. The protrusion 40b contacts the inner surface of the fixing hole portion 35a. Therefore, the wafer guide portion 40 can be fixed within the fixing hole portion 35a via the protrusion 40b, while a part of the outer circumferential surface of the wafer guide portion 40 can be separated from the inner surface of the fixing hole portion 35a.

[0065] According to the first embodiment, the susceptor 30 has a guide support portion 35 that supports a plurality of wafer guide portions 40 from below, located radially outward from the support surface 30a that supports the wafer W, with respect to the rotation axis R. The guide support portion 35 is located below the support surface 30a. Therefore, foreign matter that falls due to contact between the wafer W and the wafer guide portion 40 accumulates in the guide support portion 35 below the support surface 30a. Consequently, it is possible to suppress the accumulation of fallen foreign matter on the support surface 30a, which could cause the wafer W transported to the support surface 30a to become trapped by the foreign matter, thereby worsening the flatness and adversely affecting the film deposition characteristics.

[0066] The following describes embodiments different from those described above. In the descriptions of the following embodiments, components similar to those described in the embodiments described above may be omitted from description by using the same reference numerals as appropriate. In the following embodiments, components that are omitted from description may be the same as those described in the embodiments described above, to the extent that they do not contradict each other.

[0067] (Second embodiment) Figure 12 is a view of the susceptor 30 in the second embodiment from above. Figure 13 is a cross-sectional view showing a part of the susceptor 30 and a part of the wafer guide portion 40 in the second embodiment. In Figure 12, the outer shape of the wafer W is shown by a dashed line. As shown in Figure 12, each wafer guide portion 40 has a substantially rectangular projection 41 when viewed in the vertical direction Z. As shown in Figure 13, the main body portion 40a has a projection 41 located on the upper side and a cylindrical portion 42 located on the lower side. The outer diameter of the cylindrical portion 42 is smaller than the inner diameter of the fixing hole portion 35a. The outer circumferential surface of the cylindrical portion 42 is positioned away from the inner surface of the fixing hole portion 35a. A convex portion 40b is provided on the outer circumferential surface of the cylindrical portion 42. The upper portion of the cylindrical portion 42 and the convex portion 40b is located above the fixing hole portion 35a. The projection 41 is located above the cylindrical portion 42 and the convex portion 40b. The protrusion 41 is located above the upper surface 36 of the guide support portion 35.

[0068] As shown in Figure 12, the projection 41 has a radially extending edge when viewed in the vertical direction Z that is parallel to the direction connecting the rotation axis R and the wafer guide portion 40. The edge of the projection 41 located radially outside the cylindrical portion 42 is perpendicular to the direction connecting the rotation axis R and the wafer guide portion 40. The projection 41 has a curved surface 41a with an arc shape on its radially inner side when viewed in the vertical direction Z. The circumferential center of the curved surface 41a is located on the inscribed circle 35b when viewed in the vertical direction Z. The curved surface 41a has an arc shape with the same radius as the radius of the wafer W when viewed in the vertical direction Z. Each wafer guide portion 40 is the same as the wafer guide portion 40 in the first embodiment, except that the projection 41 is provided above the cylindrical portion 42 and the convex portion 40b.

[0069] In the first embodiment, the wafer guide portion 40 has a circular main body portion 40a that makes point contact with the outer edge of the circular wafer W when viewed in the vertical direction Z. Because the wafer W is in point contact with the main body portion 40a, it becomes prone to cracking due to stress concentration, even in directions different from the cleavage direction. In the second embodiment, the wafer guide portion 40 has a radially inner curved surface 41a that is an arc shape with the same radius as the radius of the wafer W when viewed in the vertical direction Z, so the curved surface 41a and the outer edge of the wafer W make line contact. By increasing the contact area between the curved surface 41a and the outer edge of the wafer W, stress concentration in the wafer W is alleviated and cracking can be suppressed.

[0070] (Third embodiment) Figure 14 is a view of the susceptor 30 in the third embodiment from above. The wafer guide portion 40M in the first embodiment had a mark portion M as an indicator of a predetermined direction D. As shown in Figure 14, the wafer guide portion 40M is the same as the wafer guide portion 40 in the first embodiment, except that its radial position is different from that of the other wafer guide portions 40. In the first embodiment, the predetermined direction D in which the orientation flat portion Wd extends was indicated by the direction in which the groove of the mark portion M of the wafer guide portion 40 extends. The five wafer guide portions 40 other than the wafer guide portion 40M are tangent to the inscribed circle 35b, but the wafer guide portion 40M is positioned radially inward from the position where it is tangent to the inscribed circle 35b, which serves as an indicator of the predetermined direction D.

[0071] In step S110, the control unit 90 places the wafer W on the movable part 32 such that the direction connecting the wafer guide part 40M, whose radial position is different from that of the other wafer guide parts 40, intersects with a predetermined direction D at a preset angle. As a result, the multiple wafer guide parts 40, 40M and the wafer W surrounded by the multiple wafer guide parts 40, 40M are arranged in the configuration shown in Figures 3, 8, and 9. In the first embodiment, the wafer guide part 40M required processing of the mark part M, but in the third embodiment, the wafer guide part 40M does not require processing of the mark part M, thereby reducing the cost of the film deposition process.

[0072] According to at least one embodiment described above, the film deposition method is a film deposition method that forms a film on the surface of a wafer using a vapor phase growth apparatus. The film deposition method of the embodiment includes a film deposition process that forms a film on the surface of a wafer. The vapor phase growth apparatus has a susceptor that supports the wafer and a plurality of wafer guide parts that surround the wafer. The susceptor is rotated around a rotation axis that extends in the vertical direction. The plurality of wafer guide parts are arranged at intervals in the circumferential direction around the rotation axis and protrude above the susceptor. The film deposition process includes surrounding the wafer with the plurality of wafer guide parts such that, when viewed in the vertical direction, the direction connecting the rotation axis and each wafer guide part is different from the cleavage direction of the wafer. This makes it possible to suppress deterioration of the film deposition characteristics of the film formed on the wafer, as described above. It also makes it possible to suppress the wafer from cracking during the film deposition process.

[0073] Each of the multiple wafer guides may be fixed to the inside of the multiple fixing holes in any way, provided that at least a portion of the outer surface of the part of the wafer guide located inside the fixing hole is positioned away from the inner surface of the fixing hole.

[0074] Furthermore, the entire outer surface of the portion of the wafer guide located inside the fixing hole may be in contact with the inner surface of the fixing hole. The wafer guide portion does not have to be separate from the base portion, and may be formed integrally with the base portion. Even in these cases, by arranging multiple wafer guide portions at intervals in the circumferential direction, deterioration of the film deposition characteristics of the film formed on the wafer can be suppressed as described above. In addition, by having the direction connecting the rotation axis and each wafer guide portion be different from the cleavage direction of the wafer when viewed in the vertical direction, cracking of the wafer during the film deposition process can be suppressed.

[0075] Furthermore, the number of wafer guide sections 40 is not limited to six, as long as there are two or more. The number of wafer guide sections 40 may be two, as shown in Figure 15 as a modified example of the first embodiment. Each wafer guide section 40 shown in Figure 15 has an arc shape that extends circumferentially when viewed in the vertical direction Z. The radially inner side of each wafer guide section 40 has an arc shape that lies on the inscribed circle 35b when viewed in the vertical direction Z. The two wafer guide sections 40 are arranged point-symmetrically with respect to the rotation axis R. If the maximum gap K between the two wafer guide sections 40 when viewed in the vertical direction Z is smaller than the diameter of the wafer W, the wafer W can be prevented from flying out of the gap. Each wafer guide section 40 has a first section 43 and a second section 44. The upper surface of the first section 43 is located above the surface Wa of the wafer W. The upper surface of the first portion 43 is located above the surface Wa of the wafer W, and its radially inner side is arc-shaped when viewed in the vertical direction Z, which suppresses wafer W from flying out and reduces stress concentration in the wafer W by increasing the contact area when the wafer W is in contact. The upper surface of the second portion 44 is located flush with or below the surface Wa of the wafer W. The upper surface of the second portion 44 being flush with or below the surface Wa of the wafer W suppresses obstruction of the flow of the raw material gas. In each wafer guide portion 40, three first portions 43 are arranged at intervals in the circumferential direction. In each wafer guide portion 40, two second portions 44 are arranged between the first portions 43. In the first embodiment, the circumferential position of the first portion 43 is in a direction different from the cleavage direction of the wafer W on which the wafer guide portion 40 is located, and is also different from the straight line L1a and the straight line L1b. By positioning the circumferential position of the first portion 43 and the rotation axis R in a direction different from the cleavage direction of the wafer, cracking of the wafer W can be suppressed. By positioning the circumferential position of the first portion 43 at a position different from that on the straight line L1a and the straight line L1b, the measurement of the film thickness and carrier concentration in the portion of the wafer W surrounded by multiple first portions 43 during the film deposition process is suppressed.

[0076] The material constituting the multiple wafer guide portions 40 may be different from the material constituting the base of the susceptor. In this case, the thermal conductivity of the multiple wafer guide portions 40 may be lower than that of the base of the susceptor. In this case, the transfer of heat from the base of the susceptor to the multiple wafer guide portions 40 can be further suppressed. This further suppresses the temperature of the portion of the wafer that is in contact with the multiple wafer guide portions 40 from rising. When the thermal conductivity of the multiple wafer guide portions 40 is lower than that of the base of the susceptor, the material constituting the multiple wafer guide portions 40 can be, for example, graphite, SiC, or SiN. The material constituting the multiple wafer guide portions 40 may also be single-crystal SiC having the same hexagonal crystal structure as the wafer W. When the material constituting the wafer guide portions 40 is the same as that of the wafer W, the deposits attached to the wafer guide portions 40 during the film deposition process are less likely to peel off. Therefore, it is possible to suppress the deposits attached to the wafer guide portions 40 from falling onto the support surface 30a and being sandwiched between it and the wafer W. When fabricating the wafer guide portion 40 using single-crystal SiC having a hexagonal crystal structure, for example, a SiC ingot produced by sublimation can be prepared, and the prepared SiC ingot can be processed according to the shape of the wafer guide portion 40 as described above.

[0077] The mark portion may have any shape as long as it indicates a predetermined direction along the orientation flat portion, and may be formed at any point on the wafer guide portion. The mark portion does not have to be formed on the wafer guide portion.

[0078] The film deposition method, wafer support structure, and vapor phase growth apparatus of the embodiment include the following appended embodiments. (Note 1) A method for forming a film on the surface of a wafer using a vapor phase growth apparatus, This includes a film deposition process that forms a film on the surface of the wafer, The aforementioned vapor phase growth apparatus is A susceptor that supports the wafer and rotates around a rotation axis extending in the vertical direction, It comprises a plurality of wafer guide portions arranged at intervals in the circumferential direction around the rotation axis, protruding above the susceptor and surrounding the wafer, The film deposition process includes surrounding the wafer with the plurality of wafer guide portions such that, when viewed in the vertical direction, the direction connecting the rotation axis and each of the wafer guide portions is different from the cleavage direction of the wafer. (Note 2) The wafer is formed from a single crystal having a hexagonal crystal structure. The film deposition method according to Appendix 1, wherein the film deposition process includes surrounding the wafer with the plurality of wafer guide portions such that, when viewed in the vertical direction, the direction connecting the rotation axis and each of the wafer guide portions is different from the crystal orientation of the wafer represented by <11-20>. (Note 3) The wafer guide portion is equipped with an indicator that shows a predetermined direction perpendicular to the vertical direction. When viewed in the vertical direction, the direction connecting the rotation axis and each of the wafer guide portions is different from the predetermined direction, and also different from the direction inclined 60° with respect to the predetermined direction. The wafer is a SiC substrate, The surface of the wafer is a surface that aligns with the crystal plane represented by (0001), An orientation flat portion is provided on the outer edge of the wafer, extending in the crystal orientation of the wafer represented by <11-20>. The film formation method described in Appendix 2, wherein the film formation process includes aligning the orientation flat portion along the predetermined direction. (Note 4) The film deposition method according to Appendix 3, wherein, when viewed in the vertical direction, the plurality of wafer guide portions are positioned at locations different from those on a straight line passing through the rotation axis and extending in the predetermined direction, and also at locations different from those on a straight line passing through the rotation axis and extending in a direction perpendicular to the predetermined direction. (Note 5) The aforementioned indicator is provided in the wafer guide portion, and is part of the film formation method described in Appendix 3 or Appendix 4. (Note 6) The film deposition method according to Appendix 3 or Appendix 4, wherein the index is the radial position of one of the wafer guide portions that is positioned differently from the other wafer guide portions in the rotation axis. (Note 7) The film deposition method according to any one of the appendices 1 to 6, wherein the wafer guide portion, when viewed in the vertical direction, has a circular arc shape on the radial side centered on the rotation axis, with the same radius as the wafer centered on the rotation axis. (Note 8) The film deposition method according to any one of Appendix 2 to Appendix 6, wherein the wafer guide portion is formed from a single crystal having the hexagonal crystal structure. (Note 9) A susceptor provided in a vapor phase growth apparatus, which supports a wafer and rotates around a vertically extending axis of rotation, Multiple wafer guide portions are arranged at intervals in the circumferential direction around the rotation axis, protruding above the susceptor and surrounding the wafer, Equipped with, The wafer guide portion is equipped with an indicator that shows a predetermined direction perpendicular to the vertical direction. A wafer support structure in which, when viewed in the vertical direction, the direction connecting the rotation axis and each of the wafer guide portions is different from the predetermined direction, and also different from the direction inclined 60° with respect to the predetermined direction. (Note 10) The wafer support structure according to Appendix 9, wherein the index is the radial position of one of the wafer guide portions, which is positioned differently from the other wafer guide portions, with respect to the rotation axis. (Note 11) The susceptor has a plurality of fixing holes that open upward and are spaced apart in the circumferential direction, Each of the plurality of wafer guide portions is fixed inside the plurality of fixing holes and protrudes upward from inside the plurality of fixing holes. The wafer support structure according to Appendix 9 or Appendix 10, wherein at least a portion of the outer circumferential surface of the portion of the wafer guide located inside the fixing hole is positioned away from the inner surface of the fixing hole that faces the outer circumferential surface of the portion located inside the fixing hole. (Note 12) Each of the plurality of wafer guide sections is The main body extends vertically, A protrusion provided on the outer circumferential surface of the main body, It has, The wafer support structure according to Appendix 11, wherein the protrusion contacts the inner surface of the fixing hole. (Note 13) The susceptor has a guide support portion that supports the plurality of wafer guide portions from below, located radially outward from the support surface that supports the wafer, with respect to the rotation axis. The guide support portion is located below the support surface, and is a wafer support structure according to any one of the appendices 9 to 12. (Note 14) The wafer support structure according to any one of the appendices 9 to 13, wherein the thermal conductivity of the plurality of wafer guide portions is lower than that of the susceptor. (Note 15) A wafer support structure described in any one of the items from Appendix 9 to Appendix 14, A drive unit that rotates the susceptor around the aforementioned axis of rotation, A heating unit capable of heating the susceptor, A vapor phase growth apparatus equipped with the following features.

[0079] While several embodiments of the present invention have been described, these embodiments are presented as examples only and are not intended to limit the scope of the invention. These embodiments can be carried out in a variety of other forms, and various omissions, substitutions, and modifications can be made without departing from the spirit of the invention. These embodiments and their variations are included in the scope and spirit of the invention, as well as in the claims and their equivalents. [Explanation of Symbols]

[0080] 10...Vapor phase growth apparatus, 30...Susceptor, 30a...Support surface, 31...Base, 40, 40M...Wafer guide section, 40a...Main body section, 40b...Protrusion, 35...Guide support section, 35a...Fixing hole section, 51...First heating section (heating section), 52...Second heating section (heating section), 60...Drive section, 70...Wafer support structure, D...Determined direction, L1a, L1b...Straight line, M...Marked section, R...Rotation axis, W...Wafer, Wd...Orientation flat section, Z...Vertical direction

Claims

1. A method for forming a film on the surface of a wafer using a vapor phase growth apparatus, This includes a film deposition process that forms a film on the surface of the wafer, The aforementioned vapor phase growth apparatus is A susceptor that supports the wafer and rotates around a rotation axis extending in the vertical direction, It comprises a plurality of wafer guide portions arranged at intervals in the circumferential direction around the rotation axis, protruding above the susceptor and surrounding the wafer, The film deposition process includes surrounding the wafer with the plurality of wafer guide portions such that, when viewed in the vertical direction, the direction connecting the rotation axis and each of the wafer guide portions is different from the cleavage direction of the wafer.

2. The wafer is formed from a single crystal having a hexagonal crystal structure. The film deposition method according to claim 1, wherein the film deposition process includes surrounding the wafer with the plurality of wafer guide portions such that, when viewed in the vertical direction, the direction connecting the rotation axis and each of the wafer guide portions is different from the crystal orientation of the wafer represented by <11-20>.

3. The wafer guide portion is equipped with an indicator that shows a predetermined direction perpendicular to the vertical direction. When viewed in the vertical direction, the direction connecting the rotation axis and each of the wafer guide portions is different from the predetermined direction, and also different from the direction inclined 60° with respect to the predetermined direction. The wafer is a SiC substrate, The surface of the wafer is a surface that aligns with the crystal plane represented by (0001), An orientation flat portion is provided on the outer edge of the wafer, extending in the crystal orientation of the wafer represented by <11-20>. The film formation method according to claim 2, wherein the film formation process includes aligning the orientation flat portion along the predetermined direction.

4. The film deposition method according to claim 3, wherein, when viewed in the vertical direction, the plurality of wafer guide portions are positioned at locations different from those on a straight line passing through the rotation axis and extending in the predetermined direction, and also at locations different from those on a straight line passing through the rotation axis and extending in a direction perpendicular to the predetermined direction.

5. The method for forming a film according to claim 3, wherein the indicator is a mark provided on the wafer guide portion.

6. The method for forming a film according to claim 3, wherein the index is the radial position of one of the wafer guide portions that is arranged differently from the other wafer guide portions in the rotation axis.

7. The film deposition method according to claim 1, wherein the wafer guide portion, when viewed in the vertical direction, has a circular arc shape on the radial side centered on the rotation axis, with the same radius as the wafer centered on the rotation axis.

8. The film deposition method according to claim 2, wherein the wafer guide portion is formed from a single crystal having the hexagonal crystal structure.

9. A susceptor provided in a vapor phase growth apparatus, which supports a wafer and rotates around a vertically extending axis of rotation, Multiple wafer guide portions are arranged at intervals in the circumferential direction around the rotation axis, protruding above the susceptor and surrounding the wafer, Equipped with, The wafer guide portion is equipped with an indicator that shows a predetermined direction perpendicular to the vertical direction. A wafer support structure in which, when viewed in the vertical direction, the direction connecting the rotation axis and each of the wafer guide portions is different from the predetermined direction, and also different from the direction inclined 60° with respect to the predetermined direction.

10. The wafer support structure according to claim 9, wherein the index is the radial position of one of the wafer guide portions, which is arranged differently from the other wafer guide portions, with respect to the rotation axis.

11. The susceptor has a plurality of fixing holes that open upward and are spaced apart in the circumferential direction, Each of the plurality of wafer guide portions is fixed inside the plurality of fixing holes and protrudes upward from inside the plurality of fixing holes. The wafer support structure according to claim 9, wherein at least a portion of the outer circumferential surface of the portion of the wafer guide located inside the fixing hole is arranged away from the inner surface of the fixing hole that faces the outer circumferential surface of the portion located inside the fixing hole.

12. Each of the plurality of wafer guide sections is The main body extends vertically, The protrusion provided on the outer circumferential surface of the main body, It has, The wafer support structure according to claim 11, wherein the protrusion contacts the inner surface of the fixing hole.

13. The susceptor has a guide support portion that supports the plurality of wafer guide portions from below, located radially outward from the support surface that supports the wafer, with respect to the rotation axis. The wafer support structure according to claim 9, wherein the guide support portion is located below the support surface.

14. The thermal conductivity of the plurality of wafer guide portions is lower than that of the susceptor. The wafer support structure according to claim 9.

15. A wafer support structure according to any one of claims 9 to 14, A drive unit that rotates the susceptor around the aforementioned axis of rotation, A heating unit capable of heating the susceptor, A vapor phase growth apparatus equipped with the following features.

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