Film deposition method, susceptor, and vapor phase growth apparatus

Abstract

The objective is to provide a film deposition method, a susceptor, and a vapor phase growth apparatus that can suppress the decrease in yield of semiconductor devices manufactured using wafers. [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 that supports the wafer. The susceptor has a plurality of wafer support parts that support the wafer from below and is rotated around a rotation axis that extends in the vertical direction. The plurality of wafer support parts are arranged at intervals in the circumferential direction around the rotation axis. The film deposition process includes supporting the wafer with the plurality of wafer support parts such that, when viewed in the vertical direction, the direction connecting the rotation axis and each of the wafer support parts is different from the cleavage direction of the wafer.

Description

Technical Field

[0001] Embodiments of the present invention relate to a film forming method, a susceptor, 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 susceptor is known. In such a vapor deposition apparatus, in a film forming process for forming a film on the surface of a wafer, the wafer is supported from below by an annular wafer support portion provided on the susceptor. Therefore, due to the heat transmitted from the wafer support portion, the temperature of the outer peripheral portion of the wafer tends to be higher than that of the central portion of the wafer. Accordingly, there has been a problem that the in-plane distribution of the film formed on the wafer in the outer peripheral portion of the wafer deteriorates, and the yield of semiconductor devices manufactured using the wafer decreases.

Prior Art Documents

Patent Documents

[0003] [[ID=2२]]

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 forming method, a susceptor, and a vapor deposition apparatus capable of suppressing a decrease in the yield of semiconductor devices manufactured using a wafer.

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 that supports the wafer. The susceptor has a plurality of wafer support parts that support the wafer from below and is rotated around a rotation axis that extends vertically. The plurality of wafer support parts are arranged at intervals in the circumferential direction around the rotation axis. The film deposition process includes supporting the wafer with the plurality of wafer support parts such that, when viewed vertically, the direction connecting the rotation axis and each of the wafer support 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 part of the susceptor and part of the wafer guide 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 it and the multiple wafer support parts 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 support parts 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 diagram showing multiple wafer support parts in a modified example of the first embodiment. [Figure 13] A view of the susceptor in the second embodiment from above. [Figure 14] A view of the susceptor in the third embodiment from above. [Modes for carrying out the invention]

[0007] The film deposition method, susceptor, 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 approximately disc-shaped. A portion of the outer edge of the wafer W is an orientation flat Wd that extends in a straight line. In other words, in the first embodiment, an orientation flat Wd is provided on the outer edge of the wafer W. In the first embodiment, the orientation flat 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. Figure 4 is a diagram showing the bottom surface of the hexagonal crystal lattice Rw that forms the wafer W. As shown in Figure 4, in a hexagonal crystal structure, the direction indicated by 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 substantially aligned with the crystal plane represented by (0001) in the Miller indices. 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 substantially aligned with the surface of wafer W, i.e., a substrate whose orientation is C(0001). Here, the case in which the surface of wafer W is "substantially" 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 such off-angle SiC, the off-angle is, for example, about 1° or more and 4° or less. Vectors a1, a2, and a3 are unit vectors whose orientations differ by 120° from each other and which indicate the direction from the origin O toward each atom that defines the outer periphery of the bottom surface of the crystal lattice Rw. When the surface of 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 wafer W. The sum of the coefficients of vector a1, a2, and a3 is zero. Vector c is a unit vector that represents the height direction, orthogonal to vectors a1, a2, and a3.When the surface of the wafer W is approximately aligned with the crystal plane represented by (0001), the c vector is a vector in a direction approximately parallel to the thickness direction of the wafer W.

[0010] For example, the crystal orientation shown as [11-20] in Figure 4 indicates that the coefficients of vector 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°.

[0011] 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 40, a first heating unit 51, a second heating unit 52, a third heating unit 53, and a drive unit 60.

[0012] The chamber 20 houses therein a supply pipe 24, a susceptor 30, a wafer guide 40, a first heating unit 51, a second heating unit 52, a third heating unit 53, and a drive unit 60. The chamber 20 is made of a metal such as stainless steel (SUS), for example. The chamber 20 is cylindrical and extends 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.

[0013] The supply pipe 24 is cylindrical and extends 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.

[0014] 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 a gas containing, for example, 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 a gas containing, for example, silane (SiH4) and propane (C3H8).

[0015] In the first embodiment, in the chamber 20, in addition to the raw material gas, other use gases are also supplied from the supply port 21. Examples of the use gas include an impurity gas, a carrier gas, and hydrogen chloride (HCl) gas. Examples of the impurity gas include a gas of an N-type impurity such as nitrogen, and a gas of a P-type impurity such as trimethylaluminum (TMA). The carrier gas is, for example, argon gas or hydrogen gas. More specifically, when the wafer W is carried into the vapor deposition apparatus 10 and placed on the susceptor 30, and when the wafer W after film formation is removed from the susceptor 30 and carried out of the vapor deposition apparatus 10, the carrier gas is argon gas. The carrier gas during film formation is hydrogen gas.

[0016] The susceptor 30 is a support member that supports the wafer W from below. The susceptor 30 is supported from below by the drive unit 60. As shown in FIG. 2, the susceptor 30 includes a base portion 31, a movable portion 32, and a plurality of wafer support portions 34. The base portion 31, the movable portion 32, and the plurality of wafer support portions 34 are separate from each other. The base portion 31, the movable portion 32, and the plurality of wafer support portions 34 are made of, for example, poly-SiC. The base portion 31, the movable portion 32, and the plurality of wafer support portions 34 may be made of graphite. In this case, a coat layer made of SiC may be provided on each surface of the base portion 31, the movable portion 32, and the plurality of wafer support portions 34.

[0017] In the first embodiment, the base portion 31 is annular and surrounds the rotation axis R. The base portion 31 includes an inner annular portion 33 and a guide support portion 35. As shown in FIG. 3, the inner annular portion 33 is annular and surrounds the rotation axis R. In the first embodiment, the radially inner edge portion of the inner annular portion 33 is the radially inner edge portion of the base portion 31.

[0018] 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 a substantially circular annular shape centered on the axis of rotation R. The guide support portion 35 is the part that supports the wafer guide 40 from below. 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 of the guide support portion 35 is located above the upper surface of the inner annular portion 33. The radially outward portion of the upper surface of the guide support portion 35 is in contact with the lower surface of the wafer guide 40.

[0019] 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.

[0020] 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.

[0021] 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 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 supported from below by the wafer support unit 34, and 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 support unit 34 and the wafer guide 40 by the movable unit 32. In this state, the wafer W is transported off the movable unit 32 by the transport unit 100.

[0022] 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 four fixing holes 35a. In the first embodiment, the fixing holes 35a are circular holes when viewed in the vertical direction Z. In the first embodiment, the fixing holes 35a are formed in the radially inner portion of the guide support portion 35. Figure 6 is a cross-sectional view showing a part of the susceptor 30 and a part of the wafer guide 40. As shown in Figure 6, the fixing holes 35a are recessed downward from the upper surface of the guide support portion 35. The fixing holes 35a are holes with a bottom on the lower side. The fixing holes 35a may also be holes that penetrate the base portion 31 in the vertical direction Z.

[0023] As shown in Figure 3, a mark portion 36 is formed on the base portion 31. The mark portion 36 indicates a predetermined direction along which the orientation flat portion Wd, provided on the outer edge of the wafer W, should be aligned when the wafer W is supported by a plurality of wafer support portions 34. 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 description, the predetermined direction indicated by the mark portion 36 will be referred to as "predetermined direction D". In the first embodiment, the mark portion 36 is a mark extending in the predetermined direction D. The mark portion 36 is formed on the upper surface of the guide support portion 35, on the portion located radially inward. In the first embodiment, when the wafer W is placed on the susceptor 30, the mark portion 36 is located below the portion of the radial outer edge of the wafer W that is radially inward of the orientation flat portion Wd. In other words, in the first embodiment, the mark portion 36 is covered from above by the wafer W.

[0024] The multiple wafer support portions 34 are parts that support the wafer W from below. The multiple wafer support portions 34 support the outer peripheral portion of the wafer W from below. The multiple wafer support portions 34 support the portion of the wafer W located radially outward from below. More specifically, the multiple wafer support portions 34 support the portion of the wafer W closer to the radial outer edge from below. The multiple wafer support portions 34 are arranged at intervals in the circumferential direction around the rotation axis R. In the first embodiment, the multiple wafer support portions 34 are arranged at equal intervals around the circumference. In the first embodiment, there are four multiple wafer support portions 34.

[0025] As shown in Figure 6, in the first embodiment, the plurality of wafer support portions 34 are columnar in shape and extend in the vertical direction Z. Each of the plurality of wafer support portions 34 is fixed inside a plurality of fixing holes 35a. In the first embodiment, the lower portion of each wafer support portion 34 is fixed inside each fixing hole 35a. Each wafer support portion 34 is fixed inside each fixing hole 35a, for example, by press-fitting. Each of the plurality of wafer support portions 34 protrudes upward from inside the plurality of fixing holes 35a. That is, the upper end of each wafer support portion 34 is located above the upper end of each fixing hole 35a. The upper end of each wafer support portion 34 is in contact with the back surface Wb of the wafer W.

[0026] Each of the multiple wafer support portions 34 has a main body portion 34a and a protruding portion 34b. The main body portion 34a is columnar in shape and extends in the vertical direction Z. Figure 7 is a cross-sectional view of the wafer support portion 34, 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 34a is cylindrical in shape and extends 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 34a is smaller than the inner diameter of the fixing hole portion 35a. The outer circumferential surface of the main body portion 34a 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 34a is in contact with the bottom surface of the fixing hole portion 35a. The lower surface of the main body portion 34a is, for example, a plane perpendicular to the vertical direction Z. The upper surface of the main body portion 34a is in contact with the back surface Wb of the wafer W. The upper surface of the main body 34a is, for example, a plane perpendicular to the vertical direction Z.

[0027] The upper surface of the main body portion 34a 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 34a may, for example, be a hemispherical shape that is convex upward. Alternatively, the upper end of the main body portion 34a may be a cone shape that is convex upward, or a pyramidal shape that is convex upward. In these cases, the vertex of the upper end of the main body portion 34a contacts the back surface Wb of the wafer W.

[0028] The protrusion 34b is provided on the outer circumferential surface of the main body 34a. The outer circumferential surface of the main body 34a is the outer surface of the main body 34a in the radial direction centered on the central axis J. In the following description, the radial direction centered on the central axis J may be referred to as the "second radial direction". The protrusion 34b projects outward in the second radial direction from the outer circumferential surface of the main body 34a. As shown in Figure 7, in the first embodiment, the outer surface of the protrusion 34b 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 34b 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 34b is a rib extending in the vertical direction Z. The upper end of the protrusion 34b is located below the upper end of the main body 34a. The lower end of the protrusion 34b is located above the lower end of the main body 34a. The lower end of the protrusion 34b is an inclined portion 34c whose second radial dimension decreases as it goes downwards. The lower portion of the protrusion 34b is located inside the fixing hole 35a. The upper portion of the protrusion 34b is located above the fixing hole 35a.

[0029] As shown in Figure 7, the protrusions 34b contact the inner surface of the fixing hole 35a. More specifically, the second radially outer end of the portion of the protrusions 34b located inside the fixing hole 35a contacts the inner surface of the fixing hole 35a. Multiple protrusions 34b are provided at intervals in the circumferential direction around the central axis J. The multiple protrusions 34b are arranged at equal intervals around the circumferential direction of the central axis J. In the first embodiment, there are four multiple protrusions 34b. In the first embodiment, the multiple protrusions 34b deform in the second radial direction when the wafer support portion 34 is press-fitted into the fixing hole 35a. The multiple protrusions 34b are, for example, in a state of elastic deformation in the second radial direction inside the fixing hole 35a. As described above, since inclined portions 34c are provided at the lower end of each protrusion 34b, it is easier to insert the wafer support portion 34 into the fixing hole portion 35a when press-fitting the wafer support portion 34 through the upper opening of the fixing hole portion 35a.

[0030] In each of the multiple wafer support portions 34, at least a portion of the outer circumferential surface of the portion of the wafer support portion 34 located inside the fixing hole portion 35a is positioned away from the inner surface of the fixing hole portion 35a. The outer circumferential surface of the portion of the wafer support portion 34 located inside the fixing hole portion 35a includes the outer circumferential surface of the portion of the main body portion 34a located inside the fixing hole portion 35a and the second radially outer surface of the portion of the multiple protrusions 34b located inside the fixing hole portion 35a. In the first embodiment, the second radially outer ends of the multiple protrusions 34b are in contact with the inner surface of the fixing hole portion 35a, and the other portions of the outer circumferential surface of the portion of the wafer support portion 34 located inside the fixing hole portion 35a are positioned away from the inner surface of the fixing hole portion 35a in the second radial direction. Therefore, a gap S is provided between the outer circumferential surface of the wafer support portion 34 and the inner surface of the fixing hole portion 35a. In the first embodiment, the gap S is a gas-filled void.

[0031] Figure 8 is a view from above of a wafer W supported by multiple wafer support parts 34, and shows the relationship between the crystal orientation of the wafer W and the arrangement of the multiple wafer support parts 34. 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 support part 34 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 support part 34 is different from the cleavage direction of the wafer W. In Figure 8, the direction connecting the rotation axis R and each wafer support part 34 is indicated by a dashed line passing through the rotation axis R and the central axis J of each wafer support part 34 when viewed in the vertical direction Z. Preferably, the direction connecting the rotation axis R and each wafer support part 34 is shifted by 5° or more with respect to the cleavage direction of the wafer W. It is more preferable that the direction connecting the rotation axis R and each wafer support portion 34 is offset by 10° or more with respect to the cleavage direction of the wafer W. It is even more preferable that the direction connecting the rotation axis R and each wafer support portion 34 is offset by 15° or more with respect to the cleavage direction of the wafer W.

[0032] 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 support portion 34 is different from the cleavage direction of the wafer W" means that the direction connecting the rotation axis R and the wafer support portion 34 is not parallel to the cleavage direction of the wafer W.

[0033] When viewed in the vertical direction Z, the direction connecting the rotation axis R and each wafer support portion 34 is different from the predetermined direction D indicated by the mark portion 36. When viewed in the vertical direction Z, the direction connecting the rotation axis R and each wafer support portion 34 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].

[0034] When viewed in the vertical direction Z, the direction connecting any two wafer support parts 34 from among the multiple wafer support parts 34 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 any two wafer support parts 34 from among the multiple wafer support parts 34 is different from the cleavage direction of the wafer W. In Figure 8, the direction connecting any two wafer support parts 34 is indicated by a dashed line passing through the central axes J of the two wafer support parts 34 when viewed in the vertical direction Z. It is preferable that the direction connecting any two wafer support parts 34 is shifted by 5° or more with respect to the cleavage direction of the wafer W. It is more preferable that the direction connecting any two wafer support parts 34 is shifted by 10° or more with respect to the cleavage direction of the wafer W. It is even more preferable that the direction connecting any two wafer support parts 34 is shifted by 15° or more with respect to the cleavage direction of the wafer W.

[0035] Figure 9 is a view from above of a wafer W supported by multiple wafer support parts 34, and shows the arrangement relationship between the measurement points on the wafer W after film deposition and the multiple wafer support parts 34. 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 part 36. 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 support parts 34 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 support parts 34 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 support portions 34 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.

[0036] The lines L2a and L2b shown in Figure 9 are imaginary lines extending in a direction perpendicular to the vertical direction Z. When viewed in the vertical direction Z, lines L2a and L2b extend through the rotation axis R and are inclined at 45° with respect to a predetermined direction D. The direction in which line L2a extends and the direction in which line L2b extends are perpendicular to each other. When viewed in the vertical direction Z, the multiple wafer support parts 34 are positioned at different locations on the lines L2a and L2b that extend through the rotation axis R and are inclined at 45° with respect to a predetermined direction D. When viewed in the vertical direction Z, the multiple wafer support parts 34 are preferably positioned at a distance of 5 mm or more from the lines L2a and L2b, and more preferably at a distance of 10 mm or more.

[0037] As shown in Figure 8, in the first embodiment, the plurality of wafer support portions 34 include a pair of wafer support portions 34 that straddle the rotation axis R when viewed in the vertical direction Z. The pair of wafer support portions 34 are arranged on the same straight line passing through the rotation axis R when viewed in the vertical direction Z. In the first embodiment, two pairs of such wafer support portions 34 are provided.

[0038] As shown in Figure 2, the wafer guide 40 is supported from below by the susceptor 30. The wafer guide 40 is annular in shape, surrounding the axis of rotation R. More specifically, as shown in Figure 3, the wafer guide 40 is annular in shape, centered on the axis of rotation R. The wafer guide 40 surrounds the outer edge of the wafer W. The wafer guide 40 is, for example, plate-shaped with its surface facing the vertical direction Z. The wafer guide 40 is made of, for example, poly-SiC. The wafer guide 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 40.

[0039] As shown in Figure 2, the wafer guide 40 is supported from below by the guide support portion 35. The lower surface of the wafer guide 40 is in contact with the radially outer portion of the upper surface of the guide support portion 35. The radially inner edge of the wafer guide 40 is located radially outward from the fixing hole portion 35a and the wafer support portion 34. The lower surface of the wafer guide 40 is located below the upper ends of the multiple wafer support portions 34. The upper surface of the wafer guide 40 is located above the upper surface, i.e., surface Wa, of the wafer W placed on the multiple wafer support portions 34. The upper end of the radially inner surface of the wafer guide 40 is located above the upper ends of the multiple wafer support portions 34. In other words, the upper ends of the wafer support portions 34 are located below the upper end of the radially inner end of the wafer guide 40.

[0040] Furthermore, one of the wafer guide 40 and the guide support portion 35 may have a recess that is recessed in the vertical direction Z, and the other of the wafer guide 40 and the guide support portion 35 may have a protrusion that is projected in the vertical direction Z and fits into the recess. This configuration suppresses radial displacement of the wafer guide 40 relative to the guide support portion 35.

[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 holder 61 and a power unit 62. The susceptor holder 61 is cylindrical with an opening on the upper side. The susceptor 30 is held at the upper end of the susceptor holder 61. The susceptor holder 61 is located inside the chamber 20. The lower end of the susceptor holder 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 holder 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 holder 61. The power unit 62 may also include a motor and a reduction mechanism connected to the motor. In this case, the rotation of the motor is transmitted to the susceptor holder 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. By heating the susceptor 30 with the first heating section 51 and the second heating section 52, the wafer W and wafer guide 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 support section 34 and the guide support section 35. At least a portion of the first heating section 51 overlaps with the wafer support section 34 when viewed in the vertical direction Z. In the first embodiment, the radially inward portion of the first heating section 51 overlaps with the wafer support section 34 when viewed in the vertical direction Z. The radially outward portion of the first heating section 51 overlaps with the wafer guide 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 plurality of wafer support units 34. Thus, the wafer W is placed on the susceptor 30.

[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 mark portion 36 formed on the susceptor 30. 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 support portions 34 and the wafer W supported by the plurality of wafer support portions 34 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 support portion 34, and the direction connecting any two wafer support portions 34 are 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 supported by the plurality of wafer support parts 34 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 supporting the wafer W with the plurality of wafer support parts 34 such that, when viewed in the vertical direction Z, the direction connecting the rotation axis R and each wafer support part 34 is different from the cleavage direction of the wafer W. The film deposition process includes supporting the wafer W with the plurality of wafer support parts 34 such that, when viewed in the vertical direction Z, the direction connecting any two of the plurality of wafer support parts 34 is different from the cleavage direction of the wafer W. The film deposition process includes supporting the wafer W with a plurality of wafer support parts 34 such that, when viewed in the vertical direction Z, the direction connecting the rotation axis R and each wafer support part 34 is different from the crystal orientation of the wafer W represented by <11-20>. The film deposition process also includes supporting the wafer W with the wafer support parts 34 such that, when viewed in the vertical direction Z, the direction connecting any two of the plurality of wafer support parts 34 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 includes a susceptor 30 that supports a wafer W. The susceptor 30 has a plurality of wafer support portions 34 that support the wafer W from below and is rotated around a rotation axis R extending in the vertical direction Z. The plurality of wafer support portions 34 are spaced apart in the circumferential direction around the rotation axis R. Because the plurality of wafer support portions 34 are spaced apart in the circumferential direction, the portion of the outer periphery of the wafer W that is located between adjacent wafer support portions 34 that are spaced apart in the circumferential direction does not come into contact with the susceptor 30. Therefore, compared to the case where the wafer support portion 34 is annular, there are more portions of the outer periphery of the wafer W that do not come into contact with the susceptor 30, and the temperature of the wafer W can be suppressed to rise in those portions. This suppresses a significant difference in film thickness and carrier concentration between the outer periphery of the wafer W and the central part of the wafer W, thereby preventing deterioration of the in-wafer distribution of the film formed on the outer periphery of the wafer W. Consequently, the portion of the wafer W that cannot be used as a region for forming semiconductor elements after film deposition can be reduced. Therefore, a decrease in the yield of semiconductor devices manufactured using the wafer W can be suppressed.

[0056] According to the first embodiment, when viewed in the vertical direction Z, the direction connecting the rotation axis R and each wafer support portion 34 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 supporting the wafer W with a plurality of wafer support portions 34 such that when viewed in the vertical direction Z, the direction connecting the rotation axis R and each wafer support portion 34 is different from the cleavage direction of the wafer W. Therefore, the direction in which thermal stress generated in the wafer W due to heat transmitted from each wafer support portion 34 acts can be shifted relative to the cleavage direction in which the wafer W is prone to cracking. This makes it possible to suppress cracking of the wafer W supported by the plurality of wafer support portions 34 and the generation of crystal defects, i.e., dislocations, in the wafer W due to thermal stress during the film deposition process. The effect of suppressing wafer W from cracking is preferably obtained when the angle at which the direction connecting the rotation axis R and each wafer support portion 34 is deviated from the cleavage direction of 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. Furthermore, the effect of suppressing wafer W from cracking can be obtained if the angle at which the direction connecting the rotation axis R and each wafer support portion 34 is deviated from the cleavage direction of wafer W, as viewed in the vertical direction Z, is greater than 0°.

[0057] According to the first embodiment, when viewed in the vertical direction Z, the direction connecting any two of the plurality of wafer support parts 34 is different from the cleavage direction of the wafer W. In other words, the film deposition process includes supporting the wafer W with the plurality of wafer support parts 34 such that when viewed in the vertical direction Z, the direction connecting any two of the plurality of wafer support parts 34 is different from the cleavage direction of the wafer W. Therefore, even if thermal stress caused by heat transmitted from the two wafer support parts 34 to the wafer W occurs in the direction connecting the two wafer support parts 34, this direction can be made different from the cleavage direction in which the wafer W is prone to cracking. Thus, cracking of the wafer W during the film deposition process can be further suppressed. The effect of suppressing cracking of the wafer W is preferably obtained when the angle at which the direction connecting any two of the plurality of wafer support parts 34 is shifted from the cleavage direction of the wafer W when 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. Furthermore, the effect of suppressing wafer W from cracking can be obtained if the angle at which the direction connecting any two wafer support portions 34 is shifted relative to the cleavage direction of wafer W when viewed in the vertical direction Z is greater than 0°.

[0058] 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 support portion 34 is different from the crystal orientation of the wafer W represented by <11-20>. In other words, the film deposition process includes supporting the wafer W with a plurality of wafer support portions 34 such that when viewed in the vertical direction Z, the direction connecting the rotation axis R and each wafer support portion 34 is different from the crystal orientation of the wafer W represented by <11-20>. Therefore, the direction in which thermal stress generated in the wafer W by heat transmitted from each wafer support portion 34 acts 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.

[0059] According to the first embodiment, when viewed in the vertical direction Z, the direction connecting any two of the plurality of wafer support portions 34 is different from the crystal orientation of the wafer W represented by <11-20>. In other words, the film deposition process includes supporting the wafer W with the wafer support portions 34 such that when viewed in the vertical direction Z, the direction connecting any two of the plurality of wafer support portions 34 is different from the crystal orientation of the wafer W represented by <11-20>. Therefore, cracking of the wafer W, which is formed from a single crystal having a hexagonal crystal structure, can be further suppressed.

[0060] According to the first embodiment, the susceptor 30 is provided with a mark portion 36 indicating a predetermined direction D perpendicular to the vertical direction Z. Looking at the vertical direction Z, the direction connecting the rotation axis R and each wafer support portion 34 is different from the predetermined direction D, and also different from the direction inclined 60° with respect to the predetermined direction D. The wafer W is a SiC substrate. The surface of the wafer W is a plane 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 inclined 60° with respect to the direction in which the orientation flat portion Wd extends. Therefore, by arranging each wafer support portion 34 such that the direction connecting the rotation axis R and each wafer support portion 34 when viewed in the vertical direction Z is different from both the predetermined direction D indicated by the mark portion 36 and the direction tilted 60° with respect to the predetermined direction D, and by aligning the orientation flat portion Wd with the predetermined direction D and supporting the wafer W with the multiple wafer support portions 34, the direction connecting the rotation axis R and each wafer support portion 34 when viewed in the vertical direction Z can be made 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 formed from a single crystal having a hexagonal crystal structure during the film deposition process.

[0061] 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 area of ​​the wafer W supported by multiple wafer support portions 34 tends to have a higher temperature than other parts of the wafer W. Therefore, the film thickness and carrier concentration in the area of ​​the wafer W supported by multiple wafer support portions 34 tend to deviate from the average value. Consequently, the area of ​​the wafer W supported by multiple wafer support portions 34 may not be used in the manufacture of semiconductor devices. In such cases, it may not be desirable to measure the film on the part of the wafer W that is not used in the manufacture of semiconductor devices.

[0062] In contrast to the above case, according to the first embodiment, when viewed in the vertical direction Z, the plurality of wafer support portions 34 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. By aligning the center Cw of the wafer W with the rotation axis R and aligning the direction in which the orientation flat portion Wd extends with the predetermined direction D, the wafer W is positioned on the plurality of wafer support portions 34, so that 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. In other words, 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. Viewed in the vertical direction Z, the straight line L1b coincides with the measurement line ML1b, which 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 support portions 34 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 supported by the multiple wafer support portions 34 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 supported by the multiple wafer support portions 34 during the film deposition process is suppressed.

[0063] When measuring the thickness and carrier concentration of a film formed on the surface of a wafer W, the measurement of the film formed on the wafer W may be performed in a direction tilted at 45° with respect to two directions in which multiple element formation regions We are aligned. In this case, as shown in Figure 9, the measurement of the film formed on the wafer W is performed on measurement lines ML2a and ML2b that extend in a direction tilted at 45° with respect to the direction in which the orientation flat portion Wd extends through the center Cw of the wafer W when viewed in the thickness direction of the wafer W. The direction in which measurement line ML2a extends and the direction in which measurement line ML2b extends are orthogonal to each other.

[0064] In the case described above, according to the first embodiment, when viewed in the vertical direction Z, the multiple wafer support portions 34 are positioned at locations different from those on the straight lines L2a and L2b that extend in a direction inclined at 45° with respect to a predetermined direction D, passing through the rotation axis R. By aligning the center Cw of the wafer W with the rotation axis R and aligning the direction in which the orientation flat portion Wd extends with the predetermined direction D, the wafer W is positioned on the multiple wafer support portions 34, so that when viewed in the vertical direction Z, the straight lines L2a and L2b coincide with the measurement lines ML2a and ML2b used when measuring the film on the wafer W. Therefore, even when the film on the wafer W is measured along the measurement lines ML2a and ML2b, the measurement of the film thickness and carrier concentration of the portion of the wafer W supported by the multiple wafer support portions 34 during the film deposition process is suppressed.

[0065] Furthermore, the effect of suppressing the measurement of the film thickness and carrier concentration of the portion of the wafer W supported by the multiple wafer support portions 34 during the film deposition process is preferably obtained when the multiple wafer support portions 34 are arranged at a distance of 5 mm or more from the straight lines L1a, L1b, L2a, L2b 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, L1b, L2a, L2b.

[0066] According to the first embodiment, the plurality of wafer support portions 34 include a pair of wafer support portions 34 that straddle the rotation axis R when viewed in the vertical direction Z. Therefore, the plurality of wafer support portions 34 make it easier to stably support the wafer W.

[0067] According to the first embodiment, the number of wafer support parts 34 is four or more. Therefore, the wafer W can be stably supported by the multiple wafer support parts 34 compared to the case where the number of wafer support parts 34 is three or less. Also, because the number of wafer support parts 34 is four or more, the force that each wafer support part 34 receives from the wafer W can be reduced compared to the case where the number of wafer support parts 34 is three or less. This makes it possible to suppress wear of the multiple wafer support parts 34 due to contact with the wafer W.

[0068] According to the first embodiment, the susceptor 30 includes a base 31 separate from the plurality of wafer support portions 34. The base 31 has a plurality of fixing holes 35a that open upward and are spaced apart in the circumferential direction. The plurality of wafer support portions 34 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 31 and the plurality of wafer support portions 34 are integrally molded, heat can be less easily transferred from the base 31 to each wafer support portion 34. Consequently, it is possible to suppress the temperature of the outer peripheral portion of the wafer W that is in contact with each wafer support portion 34 from rising. Consequently, it is possible to suppress the temperature of the outer peripheral portion of the wafer W from being higher than that of the central portion of the wafer W during the film deposition process. Consequently, it is possible to further suppress the significant difference in film thickness and carrier concentration between the film formed on the outer peripheral portion of the wafer W and the film formed on the central portion of the wafer W. Therefore, the deterioration of the in-wafer distribution of the film formed on the wafer W in the outer peripheral portion of the wafer W can be further suppressed. As a result, the portion of the wafer W that cannot be used as a region for forming semiconductor elements after film deposition can be further reduced. Consequently, the decrease in yield of semiconductor devices manufactured using the wafer W can be further suppressed.

[0069] According to the first embodiment, in each of the plurality of wafer support portions 34, at least a portion of the outer circumferential surface of the portion of the wafer support portion 34 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 support portion 34 compared to the case where the entire outer circumferential surface of each wafer support portion 34 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 support portions 34 can be further suppressed.

[0070] According to the first embodiment, each of the plurality of wafer support portions 34 has a main body portion 34a extending in the vertical direction Z, and a protrusion 34b provided on the outer circumferential surface of the main body portion 34a. The protrusion 34b contacts the inner surface of the fixing hole portion 35a. Therefore, the wafer support portion 34 can be fixed within the fixing hole portion 35a via the protrusion 34b, while a part of the outer circumferential surface of the wafer support portion 34 can be separated from the inner surface of the fixing hole portion 35a.

[0071] Furthermore, traces remain on the back surface Wb of the wafer W where multiple wafer support portions 34 made contact. Therefore, by checking the traces on the back surface Wb of the wafer W after film deposition, it is possible to confirm the relationship between the areas that supported the wafer W during the film deposition process and the cleavage direction of the wafer W, and the relationship between the areas that supported the wafer W during the film deposition process and the measurement locations of the film on the wafer W.

[0072] Furthermore, the number of wafer support sections 34 is not limited to four, as long as there are two or more. The number of wafer support sections 34 may be six, as shown in the wafer support section 134 in Figure 12. Figure 12 is a diagram showing the multiple wafer support sections 134 in a modified example of the first embodiment. For the six wafer support sections 134 shown in Figure 12, the arrangement relationship with respect to the cleavage direction and predetermined direction D of the wafer W is the same as that of the wafer support section 34 described above.

[0073] The following describes embodiments that differ from those described above. In the following descriptions of each embodiment, components similar to those described in the section above may be omitted from the description by using the same reference numerals as appropriate. Also, for parts corresponding to the components described in the section above each embodiment, the same name and different reference numerals will be used to explain the differences from the above-described configuration, while the explanation of similar components may be omitted. Note that, within the scope of consistency, components similar to those described in the section above each embodiment may be adopted as components whose description is omitted.

[0074] (Second embodiment) Figure 13 is a view of the susceptor 230 in the second embodiment from above. In Figure 13, the outline of the wafer W is shown by a dashed line. As shown in Figure 13, the susceptor 230 comprises five wafer support sections 234. The five wafer support sections 234 include three wafer support sections 234a, one wafer support section 234b, and one wafer support section 234c. The four wafer support sections 234, consisting of three wafer support sections 234a and one wafer support section 234b, are arranged in the same way as the four wafer support sections 34 in the first embodiment.

[0075] The wafer support portion 234b is positioned in the same location as the wafer support portion 34 of the first embodiment, which supports the portion of the radial outer edge of the wafer W that is located radially inward of the orientation flat portion Wd. The wafer support portion 234c is positioned circumferentially adjacent to the wafer support portion 234b. The wafer support portion 234c supports the portion of the radial outer edge of the wafer W that is located radially inward of the orientation flat portion Wd.

[0076] In the second embodiment, wafer support portion 234b and wafer support portion 234c form a mark portion 236. The predetermined direction D is the direction connecting wafer support portion 234b and wafer support portion 234c when viewed in the vertical direction Z. In other words, in the second embodiment, the mark portion 236 indicates a predetermined direction D along which the orientation flat portion Wd provided on the outer edge of the wafer W is aligned when the wafer W is supported by multiple wafer support portions 234, depending on the direction in which the two wafer support portions 234b and 234c are aligned. In Figure 13, the predetermined direction D is the direction in which the straight line connecting the central axis J of wafer support portion 234b and the central axis J of wafer support portion 234c extends when viewed in the vertical direction Z.

[0077] The base portion 231 is the same as the base portion 31 in the first embodiment, except that it is provided with a fixing hole for fixing the wafer support portion 234c. The other configurations of the susceptor 230 are the same as the other configurations of the susceptor 30 in the first embodiment.

[0078] (Third embodiment) Figure 14 is a view of the susceptor 330 in the third embodiment from above. In Figure 14, the outline of the wafer W is shown by a dashed line. As shown in Figure 14, the susceptor 330 comprises four wafer support portions 334. The four wafer support portions 334 are arranged in the same way as the four wafer support portions 34 in the first embodiment. The four wafer support portions 334 include three wafer support portions 334c and one wafer support portion 334d. The shape of the three wafer support portions 334c is the same as that of the wafer support portion 34 in the first embodiment.

[0079] Viewed in the vertical direction Z, the shape of one wafer support portion 334d differs from the shapes of the three wafer support portions 334c. The wafer support portion 334d has a main body portion 334a and a plurality of protrusions 334b. The main body portion 334a of the wafer support portion 334d is rectangular in shape when viewed in the vertical direction Z. In the third embodiment, the wafer support portion 334d is a mark portion indicating a predetermined direction D. In Figure 14, the side of the main body portion 334a of the rectangular wafer support portion 334d, when viewed in the vertical direction Z, that extends in the left-right direction indicates the predetermined direction D. For example, the control unit 90 can position the orientation flat portion Wd along the predetermined direction D by positioning the wafer W such that the orientation flat portion Wd is closest to the wafer support portion 334d which is the mark portion among the four wafer support portions 334, and the orientation flat portion Wd is aligned with one side of the wafer support portion 334d. The multiple protrusions 334b ​​are the same as those of the multiple protrusions 34b in the first embodiment, except that they are provided on each side of the rectangular main body portion 334a when viewed in the vertical direction Z.

[0080] The base portion 331 is the same as the base portion 31 in the first embodiment, except that the shape of the fixing hole portion 335a to which the wafer support portion 334d is fixed is rectangular when viewed in the vertical direction Z. The other configurations of the susceptor 330 are the same as the other configurations of the susceptor 30 in the first embodiment. In the third embodiment, the fixing hole portion 335a to which the wafer support portion 334c is fixed may be a mark portion. In this case, the predetermined direction D is indicated by the sides of the rectangular fixing hole portion 335a when viewed in the vertical direction Z.

[0081] 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. The susceptor has a plurality of wafer support parts that support the wafer from below and is rotated around a rotation axis that extends vertically. The plurality of wafer support parts are arranged at intervals in the circumferential direction around the rotation axis. The film deposition process includes supporting the wafer with the plurality of wafer support parts such that, when viewed vertically, the direction connecting the rotation axis and each wafer support part is different from the cleavage direction of the wafer. As a result, as described above, a decrease in the yield of semiconductor devices manufactured using the wafer can be suppressed. In addition, cracking of the wafer during the film deposition process can be suppressed.

[0082] Each of the multiple wafer support portions 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 support portion located inside the fixing hole portion is positioned away from the inner surface of the fixing hole portion.

[0083] Furthermore, the entire outer surface of the portion of the wafer support located inside the fixing hole may be in contact with the inner surface of the fixing hole. The wafer support does not have to be separate from the base, and may be formed integrally with the base. Even in these cases, by arranging multiple wafer support portions at intervals in the circumferential direction, it is possible to suppress a decrease in the yield of semiconductor devices manufactured using the wafer, as described above. In addition, by having the direction connecting the rotation axis and each wafer support portion be different from the cleavage direction of the wafer when viewed in the vertical direction, it is possible to suppress the wafer from cracking during the film deposition process, thereby further suppressing a decrease in the yield of semiconductor devices manufactured using the wafer.

[0084] The materials constituting the multiple wafer support sections may differ from the materials constituting the base of the susceptor. In this case, the thermal conductivity of the multiple wafer support sections 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 support sections can be further suppressed. This further suppresses the temperature rise of the portion of the wafer that is in contact with the multiple wafer support sections. When the thermal conductivity of the multiple wafer support sections is lower than that of the base of the susceptor, materials such as graphite, SiC, and SiN can be used to constitute the multiple wafer support sections.

[0085] The direction connecting the rotation axis and each wafer support when viewed vertically is the direction in which a straight line passing through the rotation axis and each wafer support extends when viewed vertically. The direction connecting two wafer support parts when viewed vertically is the direction in which a straight line passing through those two wafer support parts extends when viewed vertically. The mark portion can be of any shape as long as it indicates a predetermined direction along which the orientation flat portion should be aligned, and it can be formed at any point on the susceptor. The mark portion does not have to be formed on the susceptor.

[0086] The film deposition method, susceptor, 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 vapor phase growth apparatus comprises a susceptor that supports the wafer, The susceptor has a plurality of wafer support parts that support the wafer from below, and is rotated around a rotation axis that extends in the vertical direction. The plurality of wafer support portions are arranged with spacing between them in the circumferential direction around the rotation axis, The film deposition process includes supporting the wafer with the plurality of wafer support parts such that, when viewed in the vertical direction, the direction connecting the rotation axis and each of the wafer support parts is different from the cleavage direction of the wafer. (Note 2) The film deposition method according to Appendix 1, wherein the film deposition process includes supporting the wafer with the plurality of wafer support portions such that, when viewed in the vertical direction, the direction connecting any two of the plurality of wafer support portions is different from the cleavage direction of the wafer. (Note 3) The wafer is formed from a single crystal having a hexagonal crystal structure. The film deposition method according to Appendix 1 or Appendix 2, wherein the film deposition process includes supporting the wafer with the plurality of wafer support parts such that, when viewed in the vertical direction, the direction connecting the rotation axis and each of the wafer support parts is different from the crystal orientation of the wafer represented by <11-20>. (Note 4) The film deposition method according to Appendix 3, wherein the film deposition process includes supporting the wafer with the wafer support portions such that, when viewed in the vertical direction, the direction connecting any two of the plurality of wafer support portions is different from the crystal orientation of the wafer represented by <11-20>. (Note 5) The susceptor is provided with a mark portion indicating 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 support parts 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 Appendix 3 or Appendix 4, wherein the film formation process includes aligning the orientation flat portion along the predetermined direction. (Note 6) The film deposition method according to Appendix 5, wherein, when viewed in the vertical direction, the plurality of wafer support 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 7) The film deposition method according to Appendix 5 or Appendix 6, wherein, when viewed in the vertical direction, the plurality of wafer support portions are positioned at locations different from a straight line extending in a direction that passes through the rotation axis and is inclined at 45° with respect to the predetermined direction. (Note 8) The film deposition method according to any one of Appendix 1 to Appendix 7, wherein the plurality of wafer support portions include a pair of wafer support portions that straddle the rotation axis when viewed in the vertical direction. (Note 9) The film deposition method according to any one of Appendix 1 to Appendix 8, wherein the number of the plurality of wafer support portions is four or more. (Note 10) A susceptor provided in a vapor phase growth apparatus, which supports a wafer and is rotated about a rotation axis extending in the vertical direction, Multiple wafer support sections that support the wafer from below, A mark indicating a predetermined direction perpendicular to the vertical direction, Equipped with, The plurality of wafer support portions are arranged with spacing between them in the circumferential direction around the rotation axis, A susceptor in which, when viewed in the vertical direction, the direction connecting the rotation axis and each of the wafer support portions is different from the predetermined direction, and also different from the direction inclined 60° with respect to the predetermined direction. (Note 11) The susceptor according to Appendix 10, wherein, when viewed in the vertical direction, the plurality of wafer support 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 12) The susceptor according to Appendix 10 or Appendix 11, wherein, when viewed in the vertical direction, the plurality of wafer support portions are positioned at locations different from a straight line extending in a direction that passes through the rotation axis and is inclined at 45° with respect to the predetermined direction. (Note 13) The susceptor according to any one of the appendices 10 to 12, wherein the plurality of wafer support portions include a pair of wafer support portions that straddle the rotation axis when viewed in the vertical direction. (Note 14) The susceptor described in any one of the appendices 10 to 13, wherein the number of the plurality of wafer support portions is four or more. (Note 15) The base portion is separate from the aforementioned plurality of wafer support portions, The base portion has a plurality of fixing holes that open upward and are spaced apart in the circumferential direction. The susceptor according to any one of the appendices 10 to 14, wherein the plurality of wafer support portions are each fixed inside the plurality of fixing holes and each protrudes upward from inside the plurality of fixing holes. (Note 16) The susceptor according to Appendix 15, wherein in each of the plurality of wafer support portions, at least a portion of the outer circumferential surface of the portion of the wafer support portion located inside the fixing hole portion is arranged away from the inner surface of the fixing hole portion. (Note 17) Each of the plurality of wafer support portions is The main body extends vertically, A protrusion provided on the outer circumferential surface of the main body, It has, The protrusion is the susceptor described in Appendix 16, which contacts the inner surface of the fixing hole. (Note 18) The susceptor according to any one of Appendix 15 to Appendix 17, wherein the thermal conductivity of the plurality of wafer support portions is lower than that of the base portion. (Note 19) A susceptor described in any one of the appendices 10 to 18, 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.

[0087] 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]

[0088] 10...Vapor phase growth apparatus, 30, 230, 330...Susceptor, 31, 231, 331...Base, 34, 134, 234, 234a, 234b, 234c, 334, 334a...Wafer support section, 34a...Main body section, 34b, 334b...Convex section, 35a, 335a...Fixing hole section, 36, 236...Mark section, 51...First heating section (heating section), 52...Second heating section (heating section), 60...Drive section, 334b...Wafer support section (mark section), D...Determined direction, L1a, L2a, L1b, L2b...Linear, 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 vapor phase growth apparatus comprises a susceptor that supports the wafer, The susceptor has a plurality of wafer support parts that support the wafer from below, and is rotated around a rotation axis that extends in the vertical direction. The plurality of wafer support portions are arranged with spacing between them in the circumferential direction around the rotation axis, The film deposition process includes supporting the wafer with the plurality of wafer support parts such that, when viewed in the vertical direction, the direction connecting the rotation axis and each of the wafer support parts is different from the cleavage direction of the wafer.

2. The film deposition method according to claim 1, wherein the film deposition process includes supporting the wafer with the plurality of wafer support portions such that, when viewed in the vertical direction, the direction connecting any two of the plurality of wafer support portions is different from the cleavage direction of the wafer.

3. 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 supporting the wafer with the plurality of wafer support parts such that, when viewed in the vertical direction, the direction connecting the rotation axis and each of the wafer support parts is different from the crystal orientation of the wafer represented by <11-20>.

4. The film deposition method according to claim 3, wherein the film deposition process includes supporting the wafer with the wafer support portions such that, when viewed in the vertical direction, the direction connecting any two of the plurality of wafer support portions is different from the crystal orientation of the wafer represented by <11-20>.

5. The susceptor is provided with a mark portion indicating 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 support parts 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 3, wherein the film formation process includes aligning the orientation flat portion along the predetermined direction.

6. The film deposition method according to claim 5, wherein, when viewed in the vertical direction, the plurality of wafer support portions are arranged at positions different from those on a straight line passing through the rotation axis and extending in the predetermined direction, and also at positions different from those on a straight line passing through the rotation axis and extending in a direction perpendicular to the predetermined direction.

7. The film deposition method according to claim 5, wherein, when viewed in the vertical direction, the plurality of wafer support portions are arranged at positions different from those on a straight line extending in a direction that passes through the rotation axis and is inclined at 45° with respect to the predetermined direction.

8. The film deposition method according to claim 1, wherein the plurality of wafer support portions include a pair of wafer support portions that straddle the rotation axis when viewed in the vertical direction.

9. The film deposition method according to claim 1, wherein the number of the plurality of wafer support portions is four or more.

10. A susceptor provided in a vapor phase growth apparatus, which supports a wafer and is rotated about a rotation axis extending in the vertical direction, Multiple wafer support sections that support the wafer from below, A mark indicating a predetermined direction perpendicular to the vertical direction, Equipped with, The plurality of wafer support portions are arranged with spacing between them in the circumferential direction around the rotation axis, A susceptor in which, when viewed in the vertical direction, the direction connecting the rotation axis and each of the wafer support portions is different from the predetermined direction, and also different from the direction inclined 60° with respect to the predetermined direction.

11. The susceptor according to claim 10, wherein, when viewed in the vertical direction, the plurality of wafer support portions are arranged at positions different from those on a straight line passing through the rotation axis and extending in the predetermined direction, and also at positions different from those on a straight line passing through the rotation axis and extending in a direction perpendicular to the predetermined direction.

12. The susceptor according to claim 10, wherein, when viewed in the vertical direction, the plurality of wafer support portions are arranged at positions different from those on a straight line extending in a direction that passes through the rotation axis and is inclined at 45° with respect to the predetermined direction.

13. The susceptor according to claim 10, wherein the plurality of wafer support portions include a pair of wafer support portions that straddle the rotation axis when viewed in the vertical direction.

14. The susceptor according to claim 10, wherein the number of the plurality of wafer support portions is four or more.

15. The base portion is separate from the aforementioned plurality of wafer support portions, The base portion has a plurality of fixing holes that open upward and are spaced apart in the circumferential direction. The susceptor according to claim 10, wherein the plurality of wafer support portions are each fixed inside the plurality of fixing holes and each protrudes upward from inside the plurality of fixing holes.

16. The susceptor according to claim 15, wherein in each of the plurality of wafer support portions, at least a portion of the outer circumferential surface of the portion of the wafer support portion located inside the fixing hole portion is arranged away from the inner surface of the fixing hole portion.

17. Each of the plurality of wafer support portions is The main body extends vertically, A protrusion provided on the outer circumferential surface of the main body, It has, The susceptor according to claim 16, wherein the protrusion contacts the inner surface of the fixing hole.

18. The susceptor according to claim 15, wherein the thermal conductivity of the plurality of wafer support portions is lower than that of the base portion.

19. A susceptor according to any one of claims 10 to 18, 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.

Images