JP7170460B2 - SiC single crystal evaluation method and quality inspection method - Google Patents

Description

The present invention relates to a SiC single crystal evaluation method and quality inspection method.

Silicon carbide (SiC) has a dielectric breakdown field one order of magnitude larger and a bandgap three times larger than silicon (Si). In addition, silicon carbide (SiC) has properties such as a thermal conductivity that is about three times as high as that of silicon (Si). Silicon carbide (SiC) is expected to be applied to power devices, high frequency devices, high temperature operation devices and the like.

Devices such as semiconductors use SiC epitaxial wafers obtained by forming an epitaxial film on a SiC wafer. An epitaxial film provided on a SiC wafer by chemical vapor deposition (CVD) serves as an active region of a SiC semiconductor device.

Therefore, there is a demand for a high-quality SiC wafer that is free from damage such as cracks and has few defects. In this specification, the SiC epitaxial wafer means a wafer after forming an epitaxial film, and the SiC wafer means a wafer before forming an epitaxial film.

A basal plane dislocation (BPD) is one of the killer defects of SiC wafers. A part of the BPD of the SiC wafer is also inherited by the SiC epitaxial wafer, and causes deterioration of the forward characteristics when current is passed through the device in the forward direction. BPD is a defect that is considered to be caused by one of the causes of slippage that occurs on the basal plane.

As one of methods for evaluating the BPD density in SiC single crystals, an etch pit analysis method using KOH etching is known (Patent Document 1). The etch pit analysis method is a method in which etch pits are formed by KOH etching a SiC single crystal and dislocations are determined from the shape of the etch pits.

JP 2015-188003 A

However, the SiC single crystal subjected to the etch pit analysis method described in Patent Document 1 cannot be used for devices. That is, the etch pit analysis method is a destructive inspection and cannot inspect the SiC single crystal itself used for the device. Therefore, a non-destructive inspection method is required.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a SiC single crystal evaluation method capable of evaluating the SiC single crystal itself used in a device.

As a result of extensive studies, the present inventors have found that there is a correlation between the amount of curvature of the atomic arrangement plane (lattice plane) of a SiC single crystal and the basal plane dislocation (BPD) density. Therefore, it was found that the basal plane dislocation (BPD) density can be roughly estimated by evaluating the amount of curvature of the atomic arrangement plane (lattice plane) of the SiC single crystal.
That is, the present invention provides the following means in order to solve the above problems.

(1) A SiC single crystal evaluation method according to a first aspect includes the steps of measuring the amount of curvature of an atomic arrangement plane along a first direction passing through the center of a plan view, and measuring the amount of curvature of the atomic arrangement plane. and estimating a basal plane dislocation (BPD) density.

(2) The SiC single crystal evaluation method according to the above aspect may be performed on a SiC single crystal having a basal plane dislocation (BPD) density of 10000 cm ⁻² or less.

(3) The SiC single crystal evaluation method according to the above aspect includes the steps of measuring the amount of curvature of the atomic arrangement plane in a second direction perpendicular to the first direction; estimating a basal plane dislocation (BPD) density from the amount of curvature.

(4) The quality inspection method according to the second aspect includes the step of producing a plurality of lots of SiC ingots made of SiC single crystals, and the SiC single crystal evaluation method according to the above aspect. and evaluating planar dislocation (BPD) density.

(5) A quality inspection method according to a third aspect includes steps of producing a SiC ingot made of a SiC single crystal, cutting the SiC ingot in a direction intersecting the growth direction of the SiC ingot, and forming a plurality of cut bodies. and evaluating the basal plane dislocation (BPD) density of each cut body using the SiC single crystal evaluation method according to the above aspect.

(6) A quality inspection method according to a fourth aspect includes a step of producing a SiC wafer made of a SiC single crystal, and using the SiC single crystal evaluation method according to the above aspect, a plurality of and evaluating the basal plane dislocation (BPD) density at each measurement point.

By using the SiC single crystal evaluation method according to the above aspect, the SiC single crystal itself used for the device can be evaluated. In addition, it becomes possible to inspect all SiC single crystals used in devices.

FIG. 2 is a schematic diagram of a cross section of a SiC single crystal cut along a straight line extending in a first direction and passing through the center in a plan view; 1 is a diagram schematically showing an example of an atomic arrangement plane of a SiC single crystal; FIG. FIG. 4 is a diagram schematically showing another example of an atomic arrangement plane of a SiC single crystal; It is a figure for demonstrating concretely the measuring method of the curvature amount of an atomic arrangement plane. It is a figure for demonstrating concretely the measuring method of the curvature amount of an atomic arrangement plane. It is a figure for demonstrating concretely the measuring method of the curvature amount of an atomic arrangement plane. It is a figure for demonstrating concretely the measuring method of the curvature amount of an atomic arrangement plane. An example in which the radius of curvature of an atomic arrangement surface is obtained from a plurality of XRD measurement points is shown. FIG. 5 is a diagram for specifically explaining another example of a method for measuring the amount of curvature of an atomic arrangement plane; FIG. 5 is a diagram for specifically explaining another example of a method for measuring the amount of curvature of an atomic arrangement plane; The relationship between the atomic arrangement plane and the BPD density of each cut body obtained by dividing the SiC ingot manufactured under the same conditions into four in the stacking direction is shown. Fig. 2 shows the relationship between the radius of curvature of the atomic arrangement surface of different SiC ingots and the BPD density. It is the figure which planarly viewed an example of a SiC wafer. 4 shows the relationship between the radius of curvature of the atomic array surface and the BPD density for each measurement point on the SiC wafer.

Hereinafter, this embodiment will be described in detail with appropriate reference to the drawings. In the drawings used in the following description, characteristic portions may be enlarged for the sake of convenience, and the dimensional ratio of each component may differ from the actual one. The materials, dimensions, and the like exemplified in the following description are examples, and the present invention is not limited to them, and can be modified as appropriate without changing the gist of the invention.

"Evaluation method of SiC single crystal"
A method for evaluating a SiC single crystal according to the present embodiment comprises steps of measuring the amount of curvature of an atomic arrangement plane along a first direction passing through the center of a plan view, ) estimating the density.

<Measurement of Amount of Curvature of Atomic Arrangement Plane>
FIG. 1 is a schematic diagram of a cross section obtained by cutting a SiC single crystal along a straight line passing through the center in a plan view and extending in a first direction. Any direction can be set as the first direction as long as the correlation between the amount of curvature of the atomic arrangement plane and the BPD density is investigated in advance. In FIG. 1, the first direction is [1-100]. In FIG. 1, the upper side is the [000-1] direction, that is, the direction in which the carbon plane (C plane, (000-1) plane) appears when cut perpendicular to the <0001> direction. An example in which the first direction is [1-100] will be described below.

Here, crystal orientations and planes are expressed using the following parentheses as Miller indices. ( ) and { } are used when representing faces. ( ) is used to express a specific plane, and { } is used to express a generic term (aggregate plane) of equivalent planes based on crystal symmetry. On the other hand, < > and [ ] are especially used to indicate direction. [ ] is used to express a specific direction, and < > is used to express an equivalent direction due to crystal symmetry.

As shown in FIG. 1, the SiC single crystal 1 is a single crystal in which a plurality of atoms A are aligned. Therefore, as shown in FIG. 1, when microscopically looking at the cut surface of the SiC single crystal, an atomic arrangement plane 2 in which a plurality of atoms A are arranged is formed. The atomic arrangement plane 2 on the cutting plane is expressed as a line extending in a direction substantially parallel to the cutting direction obtained by connecting the atoms A arranged along the cutting plane.

The shape of the atomic arrangement plane 2 on the cut surface may be convex or concave regardless of the shape of the outermost surface of the SiC single crystal 1 . Also, the shape of the atomic arrangement plane 2 may differ depending on the cutting direction. The shape of the atomic array surface 2 is, for example, a concave shape that is concave toward the center as shown in FIG. saddle type).

The shape of the atomic arrangement plane 2 can be measured by X-ray diffraction (XRD). The surface to be measured is determined according to the direction of measurement. Assuming that the measurement direction is [hkil], the measurement surface must satisfy the relationship (mh mk min). Here, m is an integer greater than or equal to 0, and n is a natural number. For example, when measuring in the [11-20] direction, the (0004) plane is selected with m=0 and n=4, and the (22-416) plane with m=2 and n=16. On the other hand, when measuring in the [11-20] direction, the (0004) plane is selected with m=0 and n=4, and the (3-3016) plane with m=3 and n=16. That is, the measurement plane may be a different plane depending on the measurement direction, and the atomic arrangement plane does not necessarily have to be the same plane. By satisfying the above relationship, it is possible to prevent lattice curvature in the a-plane or m-plane direction, which has little effect on crystal growth, from being misidentified as lattice curvature in the c-plane direction. For measurement, either the C plane or the Si plane may be selected, but the measurement direction is not changed for one sample.

X-ray diffraction data are acquired at five points along a given direction: the center, the edge, and the midpoint between the center and the edge. If the atomic arrangement plane 2 is curved, the X-ray reflection direction changes, so the ω angle position of the peak of the output X-ray diffraction image varies between the center and other portions. The bending direction of the atomic arrangement plane 2 can be determined from the positional variation of the diffraction peak. Also, the radius of curvature of the atomic array surface 2 can be obtained from the positional variation of the diffraction peak, and the amount of curvature of the atomic array surface 2 can also be obtained.

(Specific description of the method (method 1) for measuring the amount of curvature of the atomic arrangement plane)
A method for measuring the bending direction and bending amount of the atomic arrangement surface from the XRD measurement value of the outer peripheral end portion of a sample obtained by slicing a SiC single crystal (hereinafter referred to as a wafer 20) will be described in detail.

FIG. 4 schematically shows a cross section cut along the direction of measurement of the atomic arrangement plane, eg, the [1-100] direction, passing through the center in plan view. Assuming that the radius of the wafer 20 is r, the lateral length of the cross section is 2r. 4 also shows the shape of the atomic arrangement surface 22 in the wafer 20. As shown in FIG. As shown in FIG. 4, although the shape of the wafer 20 itself is flat, the atomic arrangement surface 22 may be curved. The atomic arrangement plane 22 shown in FIG. 4 is symmetrical and curved concavely. This symmetry results from the fact that manufacturing conditions for SiC single crystals (ingots) are generally symmetrical about the center. Note that this symmetry does not have to be perfect symmetry, but means symmetry as an approximation that allows fluctuations due to fluctuations in manufacturing conditions and the like.

Next, as shown in FIG. 5, XRD is performed on both outer peripheral end portions of the wafer 20 to obtain the difference Δθ between the X-ray diffraction peak angles between the two measured points. This .DELTA..theta. is the difference between the tilts of the atomic arrangement plane 22 at the two points measured. As for the diffraction surface used for the X-ray diffraction measurement, an appropriate surface is selected according to the cut surface as described above.

Next, as shown in FIG. 6, the radius of curvature of the curved atomic arrangement surface 22 is obtained from the obtained Δθ. FIG. 6 shows a circle C which is in contact with two measured atomic arrangement planes, assuming that the curved surface of the atomic arrangement plane 22 of the wafer 20 is a part of a circle. Geometrically from FIG. 6, the central angle φ of the sector containing the circular arc with both ends at the tangent point is equal to the measured X-ray diffraction peak angle difference Δθ. The radius of curvature of the atomic arrangement plane 22 corresponds to the radius R of the arc. The arc radius R is obtained by the following relational expression.

Then, from the radius R of this arc and the radius r of the wafer 20, the amount of curvature d of the atomic array surface 22 is obtained. As shown in FIG. 7, the amount of curvature d of the atomic array plane 22 corresponds to the radius of the arc minus the distance of the perpendicular from the center of the arc to the wafer 20 . The distance of the perpendicular from the center of the arc to the wafer 20 is calculated from the Pythagorean theorem, and the following equation holds. In this specification, the curvature amount d is defined as a positive value when the curvature radius is positive (concave surface), and the curvature amount d is defined as a negative value when the curvature radius is negative (convex surface).

As mentioned above, R can also be measured from only the outer edge measurements of the wafer 20 in XRD. On the other hand, if this method is used, there is a possibility that the shape may be misunderstood when there is local distortion or the like at the measurement location. Therefore, the X-ray diffraction peak angle is measured at multiple points, and the curvature per unit length is converted from the following formula.

FIG. 8 shows an example in which the radius of curvature of the atomic arrangement plane is obtained from a plurality of XRD measurement points. The horizontal axis of FIG. 8 indicates the relative position from the wafer center, and the vertical axis indicates the diffraction peak angle of each measurement point relative to the wafer center diffraction peak angle. FIG. 8 shows an example in which the [1-100] direction of the wafer is measured and the measurement plane is (3-3016). Measurement was performed at five locations. The five points are arranged substantially on a straight line, and dθ/dr=8.69×10 ⁻⁴ deg/mm can be obtained from this slope. By applying this result to the above formula, it is possible to calculate a concave surface with R=66 m. Then, from this R and the radius r (75 mm) of the wafer, the amount of curvature d of the atomic arrangement surface is found to be 42.6 μm.

Although the example in which the shape of the atomic arrangement surface is concave has been described so far, the same is required for the convex surface. For convex surfaces, R is calculated as negative.

(Description of another method (method 2) for measuring the amount of curvature of the atomic arrangement plane)
The amount of curvature of the atomic arrangement plane may be obtained by another method. FIG. 9 schematically shows a cross section cut along the direction of measurement of the atomic arrangement plane, for example, the [1-100] direction, passing through the center in plan view. In FIG. 9, an example in which the shape of the atomic array plane 22 is concavely curved will be described.

As shown in FIG. 9, diffraction peaks of X-ray diffraction are measured at two locations, the center of the wafer 20 and the location separated from the center of the wafer 20 by a distance x. From the symmetry of the ingot manufacturing conditions, the shape of the wafer 20 can be approximately left-right symmetrical, and the atomic arrangement plane 22 can be assumed to be flat at the center of the wafer 20 . Therefore, assuming that the difference in inclination of the atomic arrangement plane 22 at two points measured as shown in FIG.

By performing measurements at a plurality of points while changing the position of the distance x from the center, it is possible to obtain the relative atomic positions of the atomic arrangement plane 22 between the wafer center and the measurement point at each point.
This method obtains the relative positions of atoms on the plane of atomic arrangement at each measurement point. Therefore, the curvature amount of the local atomic arrangement plane can be obtained. Moreover, the relative atomic positions of the atomic arrangement plane 22 in the entire wafer 20 can be shown as a graph, which is useful for intuitively grasping the arrangement of the atomic arrangement plane 22 .

Here, the case where the measurement object is the wafer 20 has been described as an example. When the object to be measured is a SiC ingot or a cut body cut from the SiC ingot, the amount of curvature of the atomic arrangement plane can be obtained in the same manner.

<Estimate of BPD density from the amount of curvature of the atomic arrangement surface>
Next, the BPD density is roughly estimated from the measured curvature of the atomic arrangement plane. FIG. 11 shows the relationship between the atomic arrangement surface and the BPD density of each cut piece obtained by dividing the manufactured SiC ingot into four pieces in the stacking direction. Table 1 below shows the relationship between the measurement position, the radius of curvature of the atomic arrangement plane, and the BPD density. The measurement position means the amount of growth of the SiC ingot from the seed crystal, and means the distance from the interface between the seed crystal and the growth region.

As shown in FIG. 11, there is a correspondence relationship between the radius of curvature of the atomic array surface and the BPD density. The BPD density tends to decrease as the radius of curvature of the atomic arrangement plane increases (the amount of curvature of the atomic arrangement plane decreases). It is thought that a crystal with residual stress inside induces a slip of the crystal plane and bends the atomic arrangement plane 2 along with the occurrence of BPD. Alternatively, conversely, it is conceivable that the atomic arrangement plane 2 having a large amount of curvature has strain and causes BPD. In any case, the greater the curvature of the atomic arrangement plane, the greater the BPD density.

The BPD density of the measurement sample can be roughly calculated from the correspondence relationship between the radius of curvature of the atomic arrangement surface and the BPD density. The correspondence relationship between the radius of curvature of the atomic arrangement surface and the BPD density can be obtained in advance by preparing a calibration curve from the measurement results of another sample prepared under the same conditions. The amount of curvature of the atomic arrangement plane may vary depending on the measurement direction (see FIGS. 2 and 3). Therefore, it is preferable to match the measurement direction of the sample for creating the calibration curve with the measurement direction (first direction) of the measurement sample.

As described above, according to the SiC single crystal evaluation method according to the present embodiment, the SiC single crystal itself used for the device can be evaluated in a non-destructive manner. In terms of quality evaluation, the actual product evaluation is more reliable than the sampling evaluation. Therefore, by using the SiC single crystal evaluation method according to the present embodiment, a more reliable evaluation can be presented to the customer. It is also possible to inspect all samples.

The BPD density of the evaluation sample (SiC single crystal) used in the SiC single crystal evaluation method according to the present embodiment is preferably 10000 cm ⁻² or less, more preferably 5000 cm ⁻² or less. BPD is caused by various factors other than the curvature of the plane of atomic arrangement. Therefore, a SiC single crystal with a high BPD density may contain BPDs caused by factors other than the curvature of the atomic arrangement plane. If such BPDs are included, the correspondence relationship between the radius of curvature of the atomic array plane and the BPD density is disturbed, and the accuracy of the calibration curve is lowered. For samples with a BPD density of 10000 cm ⁻² or less, a clear correspondence can be confirmed between the radius of curvature of the atomic arrangement surface and the BPD density.

Further, the method for evaluating a SiC single crystal according to the present embodiment includes the step of measuring the amount of curvature of the atomic arrangement plane in a second direction orthogonal to the first direction, and the step of measuring the amount of curvature of the atomic arrangement plane in the second direction. estimating a basal plane dislocation (BPD) density.

It is possible as described above to approximate the BPD density from the results in the first direction. On the other hand, the amount of curvature of the atomic arrangement plane may vary depending on the measurement direction (see FIGS. 2 and 3). Therefore, by obtaining the curvature amounts of the atomic arrangement plane in a plurality of directions and obtaining the BPD density roughly estimated from each direction, it is possible to further improve the accuracy of the approximate BPD density.

Moreover, the measurement is not limited to two directions, and may be measured in a plurality of directions. The crystal structure of SiC single crystal 1 is hexagonal. Therefore, the BPD density can be estimated with higher accuracy by measuring the curvature of the plane of atomic arrangement along six directions symmetrical with respect to the center.

"Quality inspection method"
The quality inspection method according to the present embodiment uses the SiC single crystal evaluation method described above. The SiC single crystal quality inspection can be performed for each lot of SiC ingots, for each location within one SiC ingot, and for each of a plurality of locations on a SiC wafer.

<Lot evaluation>
The quality inspection method for evaluating each lot includes a step of producing a plurality of lots of SiC ingots made of SiC single crystals, and using the above SiC single crystal evaluation method to check the basal plane dislocations ( and BPD) density.

First, a plurality of lots of SiC ingots are produced. Each SiC ingot is produced by a known method. It is preferable not to greatly change the manufacturing conditions of each SiC ingot. This is because the calibration curve showing the correspondence relationship between the amount of curvature of the atomic arrangement plane and the BPD density also changes depending on the manufacturing conditions of the SiC ingot.

Then, the amount of curvature of each atomic arrangement plane of the manufactured SiC ingot is obtained. At this time, it is preferable that the measurement position and the measurement direction in the SiC ingot be the same. When measuring the amount of curvature of the atomic arrangement plane, it is preferable to measure by the method 1 described above. According to method 2, depending on the diffraction conditions, there may be locations where measurement is difficult (particularly near one end of the wafer), and errors are likely to occur if there is a portion with poor crystallinity.

FIG. 12 shows the relationship between the radius of curvature of the atomic arrangement surface of different SiC ingots and the BPD density. In addition, in the measurement of FIG. 12, the first direction was set to [11-20]. As shown in FIG. 12, even if the results of the curvature radii of the atomic arrangement surface for different lots are collected, it is possible to confirm the correspondence between the curvature radii of the atomic arrangement surface and the BPD density. Therefore, a calibration curve can be drawn even in the measurement for each lot.

As described above, the BPD density of the SiC ingot for each lot can be evaluated by evaluating the amount of curvature of the atomic arrangement plane for each lot. Therefore, even though each lot is manufactured under the same conditions, if a lot with an extremely different amount of curvature of the atomic arrangement surface occurs, it is possible to non-destructively determine that a problem has occurred in the manufacturing process, etc. be able to. It is also possible to grasp the transition of BPD density between lots.

<Ingot evaluation>
The quality inspection method for evaluating each location in one SiC ingot includes a step of producing a SiC ingot made of a SiC single crystal, cutting the SiC ingot in a direction intersecting the growth direction of the SiC ingot, and cutting a plurality of The method includes a step of producing a cut body, and a step of evaluating the basal plane dislocation (BPD) density of each cut body using the SiC single crystal evaluation method described above.

First, a SiC ingot is produced. A SiC ingot is produced by a known method. Next, the produced SiC ingot is divided into a plurality of cut bodies. The cutting direction is a direction that intersects with the growth direction of the SiC ingot.

For each cut piece of the SiC ingot finally obtained, the amount of curvature of the atomic arrangement plane is obtained. The amount of curvature of the atomic arrangement plane is preferably measured by Method 1 described above. FIG. 11 shows the relationship between the radius of curvature of the atomic arrangement surface and the BPD density for each cut body. As described above, since the radius of curvature of the atomic arrangement plane shown in FIG. 11 and the BPD density have a corresponding relationship, it is possible to grasp the transition of the BPD density during the growth process of the SiC ingot.

<SiC wafer evaluation>
A quality inspection method for evaluating a SiC wafer for each location includes a step of producing a SiC wafer made of a SiC single crystal, and using the above-described SiC single crystal evaluation method, a plurality of samples along the first direction. Evaluating the basal plane dislocation (BPD) density at each measurement location.

A SiC wafer is obtained by cutting a SiC ingot. FIG. 13 is a plan view of an example of a SiC wafer. When evaluating a SiC wafer, the amount of curvature of the atomic arrangement plane is obtained at each of a plurality of measurement points Mp along the first direction of measurement. In this case, it is preferable to use method 2 described above. In FIG. 13, the first direction is [11-20].

The thickness of the SiC wafer for measuring the amount of curvature of the atomic array surface 2 is preferably 500 μm or more. If the thickness of the SiC wafer is 500 μm or more, warping of the SiC wafer can be suppressed. If the SiC wafer itself is warped, it becomes difficult to accurately estimate the amount of curvature of the atomic array plane 2 . The amount of warpage of the SiC wafer is preferably 5 μm or less in any direction. Here, the amount of warpage of the SiC wafer refers to the maximum distance of a vertical line drawn from the mounting surface on the flat surface side of the sample toward the flat surface when the sample is mounted on the flat surface.

FIG. 14 shows the relationship between the radius of curvature of the atomic arrangement plane and the BPD density for each measurement point Mp of the SiC wafer. As shown in FIG. 14, even when a predetermined measurement point Mp, which is a region of the SiC wafer, is measured, a correspondence relationship is confirmed between the radius of curvature of the atomic arrangement plane and the BPD density. That is, it is possible to roughly estimate not only the BPD density as the average value of the entire SiC single crystal as in lot evaluation and ingot evaluation, but also the BPD density in one region of the wafer.

Although the preferred embodiments of the present invention have been described in detail above, the present invention is not limited to specific embodiments, and various can be transformed or changed.

1 SiC single crystal, 2, 22 atomic arrangement surface, wafer 20, A atom

Claims (7)

measuring the amount of curvature of the atomic arrangement plane along a first direction passing through the center in plan view;
estimating a basal plane dislocation (BPD) density from the amount of curvature of the atomic arrangement plane;
measuring the amount of curvature of the atomic arrangement plane in a second direction perpendicular to the first direction;
estimating a basal plane dislocation (BPD) density from the amount of curvature of the atomic arrangement plane in the second direction;
A method for evaluating a SiC single crystal having 2. The SiC single crystal evaluation method according to claim 1, wherein the SiC single crystal having a basal plane dislocation (BPD) density of 10000 cm ⁻² or less is evaluated. a step of measuring the amount of curvature of the atomic arrangement plane along six directions passing through the center in plan view and symmetrical with respect to the center;
and estimating a basal plane dislocation (BPD) density from the measured curvature of the atomic arrangement plane in each of the six directions. a step of producing a plurality of lots of SiC ingots made of SiC single crystal;
A quality inspection method comprising the step of evaluating basal plane dislocation (BPD) densities of SiC ingots for each lot using the SiC single crystal evaluation method according to any one of claims 1 to 3. a step of producing a SiC ingot made of SiC single crystal;
cutting the SiC ingot in a direction intersecting the growth direction of the SiC ingot to produce a plurality of cut bodies;
A quality inspection method comprising the step of evaluating a basal plane dislocation (BPD) density for each cut body using the SiC single crystal evaluation method according to any one of claims 1 to 3. a step of producing a SiC wafer made of SiC single crystal;
A quality inspection method comprising the step of evaluating a basal plane dislocation (BPD) density at each of a plurality of measurement points along the first direction using the SiC single crystal evaluation method according to claim 1 or 2. . a step of producing a SiC wafer made of SiC single crystal;
A quality inspection method comprising: using the SiC single crystal evaluation method according to claim 3 to evaluate basal plane dislocation (BPD) densities at each of a plurality of measurement points along the first direction.

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