JP2006001836A - SiC single crystal and SiC seed crystal - Google Patents

Abstract

To provide a high-quality SiC single crystal and a SiC seed crystal that are substantially free from micropipe defects, spiral dislocations, edge dislocations, and stacking faults.
In the first growth step, a surface having an offset angle of ± 20 ° or less from the {1-100} plane or a surface having an offset angle of ± 20 ° or less from the {11-20} plane is defined as the first growth surface. A one-growth crystal is produced, and in the intermediate growth step, the n-th growth is performed with a plane inclined by 45 to 90 ° from the (n−1) -th growth plane and 60 to 90 ° inclined from the {0001} plane as the n-th growth plane. A crystal is produced, and in the final growth step, a surface having an offset angle of ± 20 ° or less from the {0001} plane of the (N-1) -th growth crystal is defined as the final growth surface 35, and screw dislocations and A bulk SiC single crystal 30 with reduced edge dislocations is grown.
[Selection] Figure 3

Description

  The present invention relates to a SiC single crystal and a SiC seed crystal.

  Conventionally, SiC semiconductors using SiC single crystals have been expected as candidate materials for next-generation power devices that replace Si semiconductors. In order to realize a high-performance SiC power device, it is an indispensable condition to reduce a leakage current generated in the SiC semiconductor. It is considered that defects such as micropipe defects, spiral dislocations, edge dislocations, and stacking faults generated in the SiC single crystal cause leakage current of the SiC semiconductor.

As shown in FIG. 4, the SiC single crystal has {0001} plane (c plane) as main plane orientations, {1-100} plane (a plane) and {11-20} plane perpendicular to the {0001} plane. (A surface).
Conventionally, as a method for obtaining the SiC single crystal, a SiC seed crystal that exposes a plane within an offset angle of 10 ° from the {0001} plane (c plane) or {0001} plane as a seed crystal plane is used. A so-called c-plane growth method has been used in which a SiC single crystal is grown on the seed crystal surface by a precipitation method or the like. However, in such a grown crystal (c-plane grown crystal) with the {0001} plane as a seed crystal plane and grown in the <0001> direction, the micropipe defect is in a direction substantially parallel to the <0001> direction. There is a problem that a great number of linear defects such as screw dislocations and edge dislocations occur.

  In order to solve the above-mentioned problem, Patent Document 1 discloses, as shown in FIG. 6, this seed crystal having a seed crystal face 95 as a face having an inclination from the {0001} plane of 60 to 120 ° (preferably 90 °). A method of obtaining a growth crystal (a-plane growth crystal) 90 by a-plane growth of 9 is disclosed. It has been clarified that the a-plane grown crystal 90 does not include micropipe defects or screw dislocations.

However, the a-plane grown crystal 90 includes a high-density stacking defect 91. An SiC single crystal containing such stacking faults 91 at a high density has an increased electrical resistance in the direction across the stacking faults 91. Therefore, the a-plane grown crystal 9 cannot be used for manufacturing a SiC power device.
Further, in the SiC single crystal, edge dislocations 92 having Burgers vectors parallel and orthogonal to the <0001> direction are present at high density. When a seed crystal having an exposed {0001} plane is prepared from a SiC single crystal containing such edge dislocations 92 at high density and c-plane growth is performed, spiral dislocations or new ones are caused by the edge dislocations 92. There is a problem that an edge dislocation occurs.

Japanese Patent Laid-Open No. 5-262599

  The present invention has been made in view of such conventional problems, and is intended to provide a high-quality SiC single crystal and SiC seed crystal that hardly contain micropipe defects, spiral dislocations, edge dislocations, and stacking faults. It is what.

The first invention is a bulk SiC single crystal with reduced screw dislocations and edge dislocations,
The SiC single crystal is obtained by a manufacturing method including N growth steps (N is a natural number of N ≧ 3), and each growth step is divided into an nth growth step (n is a natural number and starts from 1 and ends with N). Ordinal number)
In the first growth step where n = 1, a surface having an offset angle of ± 20 ° or less from the {1-100} plane or a surface having an offset angle of ± 20 ° or less from the {11-20} plane is used as the first growth surface. Using the exposed first seed crystal, a SiC single crystal is grown on the first growth surface to produce a first growth crystal,
n = 2, 3,. . . In the (N-1) th intermediate growth step, a surface inclined by 45 to 90 ° from the (n-1) th growth surface and inclined by 60 to 90 ° from the {0001} surface is defined as the nth growth surface. An n-th crystal is produced from the (n-1) -th growth crystal, and an SiC single crystal is grown on the n-th growth surface of the n-th crystal to produce an n-th growth crystal.
In the final growth step where n = N, the final seed crystal in which the plane having an offset angle of ± 20 ° or less from the {0001} plane of the (N-1) -th growth crystal is exposed as the final growth plane is (N-1). ) A SiC single crystal produced from a grown crystal, and a bulk SiC single crystal is grown on the final growth surface of the final seed crystal.

In the first growth step of the present invention, a surface within the offset angle of 20 ° from the so-called a-plane, which is the {1-100} plane or the {11-20} plane, is used as the first growth plane.
Therefore, the first growth crystal grows in a direction orthogonal to the first growth surface, which corresponds to so-called a-plane growth. Therefore, the micropipe defect and the screw dislocation do not occur in the first grown crystal.
However, in the first seed crystal used in the first growth step, there are micropipe defects, screw dislocations, edge dislocations, and composite dislocations thereof. Therefore, edge dislocations having Burgers vectors parallel to and perpendicular to the <0001> direction due to these defects are inherited from the surface of the first growth surface. At this time, the edge dislocations exist so as to extend in a direction parallel to the growth direction of the first growth crystal.

Next, in the intermediate growth step, a surface inclined by 45 to 90 ° from the (n-1) th growth surface and inclined by 60 to 90 ° from the {0001} surface, that is, substantially a-plane is defined as the nth growth surface. An n-th seed crystal is produced from the (n-1) -th growth crystal, and an SiC single crystal is grown on the n-th growth surface to produce an n-th growth crystal.
Therefore, the edge dislocations included in the (n-1) th grown crystal are hardly exposed on the surface of the nth seed crystal, and therefore the edge dislocations are hardly generated in the nth grown crystal. In addition, the growth of the SiC single crystal in the intermediate growth step occurs in the direction of substantially a-plane growth. Therefore, micropipe defects and screw dislocations do not occur in the grown crystal in the intermediate growth step.

The intermediate growth step can be performed once (when N = 3) or repeated a plurality of times. Each time the number of intermediate growth steps is increased, the so-called dislocation density of the obtained grown crystal can be decreased exponentially.
However, in the intermediate growth step, the SiC single crystal is grown substantially in the direction of a-plane growth, and thus it is inevitable that a stacking fault peculiar to the a-plane growth crystal occurs.

In the final growth step, a final seed crystal is formed by exposing a plane having an offset angle of ± 20 ° or less from the {0001} plane of the (N-1) -th grown crystal, that is, substantially the c-plane as the final growth plane. Therefore, there are almost no edge dislocations having Burgers vectors parallel and perpendicular to the <0001> direction on the final growth surface. Therefore, an edge dislocation that is a dislocation having a Burgers vector orthogonal to the <0001> direction does not occur in the SiC single crystal obtained by growing the final seed crystal (hereinafter referred to as a final SiC single crystal as appropriate). In addition, micropipe defects and spiral dislocations, which are defects having Burgers vectors in a direction parallel to the <0001> direction, do not occur.
Further, in the final growth step, a SiC single crystal is grown from the final seed crystal in a substantially c-plane growth direction. Therefore, the stacking fault contained in the final seed crystal at a high density hardly exists in the final SiC single crystal. This is because the stacking fault is not inherited by growth in the <0001> direction (so-called c-plane growth).

Therefore, according to the present invention, it is possible to provide a high-quality SiC single crystal that hardly contains micropipe defects, spiral dislocations, edge dislocations, and stacking faults. Thus, as described above, the SiC single crystal has high quality with almost no micropipe defects, spiral dislocations, edge dislocations, and stacking faults in the crystal. Therefore, it is very effective as a material for next-generation power devices.
In the present invention, {1-100}, {11-20} and {0001} represent plane indices of so-called crystal planes. In the above surface index, the “-” symbol is usually added on the number, but in the present specification and drawings, it is added on the left side of the number for the convenience of document preparation. Further, <0001>, <11-20>, and <1-100> represent directions in the crystal, and the handling of the “−” symbol is the same as the above-described plane index.

A second invention is an SiC seed crystal for growing a bulk SiC single crystal with reduced screw dislocations and edge dislocations, and the SiC seed crystal is (N-1) times (N is Obtained by a manufacturing method including a growth step of N ≧ 3 (natural number) and a seed crystal preparation step performed after the growth step, and each growth step is an nth growth step (n is a natural number and starts from 1 and ends with N−1). Ordinal number)
In the first growth step where n = 1, a surface having an offset angle of ± 20 ° or less from the {1-100} plane or a surface having an offset angle of ± 20 ° or less from the {11-20} plane is used as the first growth surface. Using the exposed first seed crystal, a SiC single crystal is grown on the first growth surface to produce a first growth crystal,
n = 2, 3,. . . In the (N-1) th intermediate growth step, a surface inclined by 45 to 90 ° from the (n-1) th growth surface and inclined by 60 to 90 ° from the {0001} surface is defined as the nth growth surface. An n-th crystal is produced from the (n-1) -th growth crystal, and an SiC single crystal is grown on the n-th growth surface of the n-th crystal to produce an n-th growth crystal.
In the seed crystal production step, the SiC seed crystal is characterized in that a surface having an offset angle of ± 20 ° or less from the {0001} plane of the (N-1) -th growth crystal is exposed as a final growth surface.

The SiC seed crystal is the same as the final seed crystal in the first invention. Therefore, as described above, the SiC seed crystal does not include micropipe defects and screw dislocations. Further, dislocations having Burgers vectors parallel to and perpendicular to the <0001> direction are hardly exposed on the growth surface of the SiC seed crystal. The SiC seed crystal has a plane having an offset angle of ± 20 ° or less from the {0001} plane as a final growth plane, and grows in a substantially <0001> direction. Therefore, the final SiC single crystal obtained by growing the SiC seed crystal contains almost no stacking faults.
Therefore, when a SiC single crystal is grown using the SiC seed crystal of the present invention, a high-quality SiC single crystal can be easily produced without including micropipe defects, spiral dislocations, edge dislocations, and stacking faults. Can do.

As described above, the SiC seed crystal has almost no dislocations or defects on the final growth surface. Therefore, when a SiC single crystal is grown using the SiC seed crystal, dislocations and defects are hardly generated in the SiC single crystal, and a high-quality defect-free SiC single crystal can be provided.
Also, since the seed crystal can be manufactured once, the same crystal can be manufactured repeatedly. Therefore, when the SiC seed crystal is used, a high-quality defect-free SiC single crystal can be easily manufactured in large quantities.

In the present invention, the first growth plane is a plane having an offset angle of ± 20 ° or less from the {1-100} plane or {11-20} plane, which is a {1-100} plane or {11-20} It is a concept that includes surfaces.
Here, the first growth plane is preferably a {1-100} plane or a {11-20} plane.
In this case, the first growth grows in the <1-100> or <11-20> direction (a-plane growth). Therefore, it is possible to more effectively reduce penetration defects in the <0001> direction included in the first growth crystal.

In the intermediate growth step, the nth growth surface is preferably a surface inclined by 80 ° to 90 ° from the (n−1) th growth surface and inclined by 80 ° to 90 ° from the {0001} surface. .
In this case, edge dislocations having Burgers vectors parallel and orthogonal to the <0001> direction can be more effectively reduced.
The final growth plane is preferably the {0001} plane of the (N-1) th growth crystal.
In this case, since the final seed crystal can be grown in the <0001> direction, it is possible to prevent a stacking fault from occurring in the SiC single crystal.

Further, it is preferable to remove the deposits and the work-affected layer before growing the SiC single crystal on each growth surface.
In this case, it is possible to prevent dislocations inherited from the respective growth surfaces due to the deposits and the work-affected layer to the grown crystals. Examples of methods for removing the deposits and the work-affected layer include chemical cleaning, reactive ion etching (RIE), and sacrificial oxidation.

  Further, from the SiC single crystal obtained by the final growth step, a seed crystal having a plane whose offset angle is ± 20 ° or less from the {0001} plane of the SiC single crystal is exposed as a growth surface is cut out, and the seed crystal is used. SiC single crystal can be manufactured.

  In this case, the SiC single crystal obtained in the final growth step, that is, the seed crystal cut out from the final SiC single crystal is used to replicate a high-quality SiC single crystal similar to the final SiC single crystal. Can do. Further, by repeating the cutting of the seed crystal similar to the above and the growth using the seed crystal, the same SiC single crystal as the final SiC single crystal can be replicated over and over again.

In the first growth step and the intermediate growth step, the surface of the seed crystal is thermally etched at a growth temperature or a temperature within ± 400 ° C. from the growth temperature, or an etching gas is contained in a vessel for performing the growth. It is preferable to carry out a preliminary step of introducing, followed by growth to a growth temperature.
In this case, it is possible to prevent dislocations inherited from the respective growth surfaces due to the deposits and the work-affected layer on the surfaces of the respective growth surfaces used in the first growth step and the intermediate growth step. Examples of the etching gas include H ₂ and HCl.

Moreover, it is preferable to use a sublimation reprecipitation method for the growth of the SiC single crystal on the seed crystal.
In this case, since a sufficient growth height can be obtained, a large-diameter SiC single crystal or SiC seed crystal can be produced.

The thickness of the seed crystal is preferably 1 mm or more.
In this case, it is possible to prevent dislocations generated in the grown crystal due to the stress due to the difference in thermal expansion between the seed crystal and the object to which the seed crystal is fixed. That is, by sufficiently increasing the thickness of the seed crystal, it is possible to prevent the stress from distorting the lattice constituting the seed crystal and generating dislocations in the grown crystal. In particular, when the area A of the growth surface of the seed crystal exceeds 500 mm ² , it is necessary to make the thickness of the seed crystal larger than 1 mm. Assuming that the minimum necessary thickness at this time is tseed, an equation of tseed = A ^1/2 × 2 / π is given.
In addition, the said seed crystal and a growth crystal are the concept containing all the seed crystals and all the growth crystals in this invention.

Example 1
The SiC single crystal and the manufacturing method thereof according to the embodiment of the present invention, the SiC seed crystal and the manufacturing method thereof will be described.
The method for producing a SiC single crystal according to the present invention is a method for producing a bulk SiC single crystal by growing a SiC single crystal on a seed crystal made of a SiC single crystal, as shown in FIGS. This manufacturing method includes N (N = 3 in this example) growth steps, and each growth step is expressed as an nth growth step (n is a natural number and starts with 1 and ends with N).
First, as shown in FIG. 1, in the first growth step where n = 1, a surface having an offset angle ± 20 ° or less from the {1-100} plane, or an offset angle ± 20 ° or less from the {11-20} plane Using the first seed crystal 1 exposed as the first growth surface 15, an SiC single crystal is grown on the first growth surface 15 to produce the first growth crystal 10 (first growth step).
Next, as shown in FIG. 2, in the intermediate growth step as the second growth step where n = 2, the surface is inclined by 45 to 90 ° from the first growth surface and inclined by 60 to 90 ° from the {0001} surface. Is formed as a second growth surface 25, and a SiC single crystal is grown on the second growth surface 25 of the second seed crystal 2 to produce a second growth crystal 20 (intermediate growth). Process).
As shown in FIG. 3, in the final growth step where n = N (N = 3), a surface having an offset angle of ± 20 ° or less from the {0001} plane of the second growth crystal is exposed as the final growth surface 35. The final seed crystal 3 is prepared, and a bulk SiC single crystal 30 is grown on the final growth surface 35 of the final seed crystal 3 (final growth step).

Hereinafter, this example will be described in detail.
In this example, as shown in FIGS. 1 to 5, a SiC single crystal is grown by growing a SiC single crystal on a seed crystal made of a SiC single crystal by a sublimation reprecipitation method. In this example, as described above, N = 3, that is, an example including three growth steps.
First, a SiC single crystal grown by a sublimation reprecipitation method was prepared. As shown in FIG. 4, the SiC single crystal has a {0001} plane, a {1-100} plane perpendicular to the {0001} plane, and a {11-20} plane as main plane orientations. Further, the direction perpendicular to the {0001} plane is the <0001> direction, the direction perpendicular to the {1-100} plane is the <1-100> direction, and the direction perpendicular to the {11-20} plane is <11-20>. It is.
As shown in FIG. 1, the SiC single crystal was cut so that the {1-100} plane of the SiC single crystal was exposed as the first growth surface 15, and the first growth surface 15 was further processed and polished. In addition, the surface of the first growth surface 15 was chemically washed to remove deposits, and the work-affected layer accompanying cutting / polishing was removed by RIE (Reactive Ion Etching), sacrificial oxidation, or the like. Further, the surface of the first growth surface 15 was thermally etched to form the first seed crystal 1. The thickness of the first seed crystal 1 is 3 mm.

  Next, as shown in FIG. 5, the first seed crystal 1 and the SiC raw material powder 75 were placed in the crucible 6 so as to face each other. At this time, the first seed crystal 1 was fixed to the inner surface of the lid body 65 of the crucible 6 with an adhesive or the like. And the said crucible 6 was heated at 2100-2400 degreeC in pressure reduction inert atmosphere. At this time, the temperature on the SiC raw material powder 75 side was set 20 to 200 ° C. higher than the temperature on the first seed crystal 1 side. Thereby, the SiC raw material powder 75 in the crucible 6 was sublimated by heating and deposited on the first seed crystal 1 having a temperature lower than that of the SiC raw material powder 75 to obtain the first growth crystal 10.

  Next, as shown in FIGS. 1 and 2, a plane inclined from the first growth crystal 10 by 90 ° from the first growth surface 15 and by 90 ° from the {0001} plane, that is, a {11-20} plane is formed. The second seed crystal 2 as the second growth surface 25 was produced in the same manner as the first seed crystal 1. Then, the second seed crystal 2 was grown in the same manner as the first seed crystal 1, and a second growth crystal 20 was obtained.

  Next, as shown in FIGS. 2 to 3, the final seed crystal (third seed crystal) 3 having the surface 50 of the second growth crystal 20 as the final growth surface (third growth surface) 35 is the first seed crystal 1. The SiC single crystal 30 was produced in the same manner as the second seed crystal 2 and a SiC single crystal was grown from the final seed crystal 3.

Hereinafter, the function and effect of this example will be described.
In the first growth step of this example, the {1-100} plane is used as the first growth plane 15.
Therefore, the first growth crystal 10 grows in a direction perpendicular to the first growth surface 15, which corresponds to so-called a-plane growth. Therefore, the micropipe defect and the screw dislocation do not occur in the first growth crystal 10. However, defects such as micropipe defects, screw dislocations, edge dislocations, and composite dislocations exist in the first seed crystal. Therefore, edge dislocations having Burgers vectors parallel to and orthogonal to the <0001> direction are inherited from the surface of the first growth surface in the first growth crystal 10. At this time, the edge dislocations exist so as to extend in a direction parallel to the growth direction of the first growth crystal.

In the intermediate growth step, the second seed crystal 2 having the second growth surface 25 with a surface inclined by 90 ° from the first growth surface 15 and 90 ° from the {0001} surface, that is, the {11-20} surface, is formed. I am making it.
Therefore, the edge dislocations included in the first growth crystal 10 are hardly exposed on the surface of the second seed crystal 2. Therefore, even if the SiC single crystal is grown on the second growth surface 25, the edge dislocation inherited from the second seed crystal 2 is almost excluded in the second growth crystal 20. In the intermediate growth step, the second seed crystal 2 grows in the direction of substantially a-plane growth. Therefore, micropipe defects and screw dislocations do not occur in the second growth crystal 20.

In the final growth step, the final seed crystal 3 in which the {0001} plane of the second growth crystal 20 is exposed as the final growth surface 35 is produced. Therefore, there is no edge dislocation having a Burgers vector parallel and perpendicular to the <0001> direction on the final growth surface 35. Therefore, edge dislocations, which are dislocations having a Burgers vector orthogonal to the <0001> direction, do not occur in the final SiC single crystal 30. In addition, micropipe defects and spiral dislocations, which are defects having Burgers vectors in a direction parallel to the <0001> direction, do not occur.
In the final growth step, the final seed crystal 3 is grown in the <0001> direction. Therefore, stacking faults included in the final seed crystal 3 at a high density hardly exist in the final SiC single crystal 30. This is because the stacking fault is not inherited by growth in the <0001> direction.

  Further, in this example, before the SiC single crystal is grown on the first growth surface, the second growth surface 25 and the final growth surface 35, the deposits and the work-affected layer are removed. Therefore, it is possible to prevent dislocation inherited from each growth surface to each growth crystal due to the deposits and the work-affected layer.

  In the first growth process and the intermediate growth process, the surfaces of the various crystals 1 and 2 are thermally etched. Therefore, it is possible to prevent dislocations inherited from the growth surfaces 15 and 25 to the growth crystals 10 and 20 due to the deposits on the surfaces of the growth surfaces 15 and 25 and the work-affected layers.

The thicknesses of the first seed crystal, intermediate seed crystal, and final seed crystal are 1 mm or more.
Therefore, it is possible to prevent dislocations occurring in the grown crystals 10, 20, 30 due to the stress due to the difference in thermal expansion between the various crystals 1, 2, 3 and the lid 65 in contact with the seed crystal.

  Therefore, according to this example, it is possible to provide a high-quality SiC single crystal and a manufacturing method thereof, and a SiC seed crystal and a manufacturing method thereof, which hardly include micropipe defects, spiral dislocations, edge dislocations, and stacking faults. it can.

In this example, N = 3 and the intermediate growth process is performed only once. However, the intermediate growth process may be repeated a plurality of times.
That is, in the intermediate growth process of this example, the second growth crystal 20 was obtained with the {11-20} plane as the second growth plane 25. From the second growth crystal 20, a plane inclined by 90 ° from the second growth plane 25 and 90 ° from the {0001} plane, that is, a {1-100} plane is defined as a third growth plane in the third growth step. A SiC single crystal is grown on this to produce a third growth crystal. Furthermore, the intermediate growth step can be repeated from the third growth crystal, such as a fourth growth step, a fifth growth step,..., (N-1) step.
In this case, every time the number of intermediate growth steps is increased, the so-called dislocation density of the grown crystal obtained here can be decreased exponentially.

Explanatory drawing which shows the 1st growth process concerning Example 1. FIG. FIG. 3 is an explanatory diagram illustrating an intermediate growth process according to the first embodiment. FIG. 3 is an explanatory diagram showing a final growth process according to the first embodiment. FIG. 3 is an explanatory view showing main surface orientations of the SiC single crystal according to Example 1; The manufacturing method of the SiC single crystal and SiC seed crystal by the sublimation recrystallization method concerning Example 1. FIG. Explanatory drawing which shows the relationship of a surface growth, edge dislocation, and a stacking fault concerning a prior art example.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 1st seed crystal 15 1st growth surface 10 1st growth crystal 2 2nd seed crystal 25 2nd growth surface 20 2nd growth crystal 3 Final seed crystal (SiC seed crystal)
35 Final growth surface 30 SiC single crystal (final SiC single crystal)

Claims (9)

A bulk SiC single crystal with reduced screw dislocations and edge dislocations,
The SiC single crystal is obtained by a manufacturing method including N growth steps (N is a natural number of N ≧ 3), and each growth step is divided into an nth growth step (n is a natural number and starts from 1 and ends with N). Ordinal number)
In the first growth step where n = 1, a surface having an offset angle of ± 20 ° or less from the {1-100} plane or a surface having an offset angle of ± 20 ° or less from the {11-20} plane is used as the first growth surface. Using the exposed first seed crystal, a SiC single crystal is grown on the first growth surface to produce a first growth crystal,
n = 2, 3,. . . In the (N-1) th intermediate growth step, a surface inclined by 45 to 90 ° from the (n-1) th growth surface and inclined by 60 to 90 ° from the {0001} surface is defined as the nth growth surface. An n-th crystal is produced from the (n-1) -th growth crystal, and an SiC single crystal is grown on the n-th growth surface of the n-th crystal to produce an n-th growth crystal.
In the final growth step where n = N, the final seed crystal in which the plane having an offset angle of ± 20 ° or less from the {0001} plane of the (N-1) -th growth crystal is exposed as the final growth plane is (N-1). (1) A SiC single crystal produced from a grown crystal, and growing a bulk SiC single crystal on the final growth surface of the final seed crystal.   2. The seed crystal according to claim 1, wherein a seed crystal having a plane with an offset angle of ± 20 ° or less exposed from the {0001} plane of the SiC single crystal as a growth plane is cut out from the SiC single crystal obtained by the final growth step. A SiC single crystal obtained by growing a SiC single crystal using   3. The method according to claim 1, wherein in the first growth step and the intermediate growth step, the surfaces of the various crystals are thermally etched or grown at a growth temperature or a temperature within ± 400 ° C. from the growth temperature. A SiC single crystal characterized by performing a preliminary step of introducing an etching gas into the container, and then performing growth by shifting to a growth temperature.   The SiC single crystal according to any one of claims 1 to 3, wherein a sublimation reprecipitation method is used for growing the SiC single crystal on the various crystals.   The SiC single crystal according to any one of claims 1 to 4, wherein the various crystals have a thickness of 1 mm or more. An SiC seed crystal for growing a bulk SiC single crystal with reduced screw dislocations and edge dislocations, wherein the SiC seed crystal is (N-1) times (N is a natural number of N ≧ 3). Each growth step (where n is a natural number and starts with 1 and ends with (N-1)) as a n-th growth step. If expressed,
In the first growth step where n = 1, a surface having an offset angle of ± 20 ° or less from the {1-100} plane or a surface having an offset angle of ± 20 ° or less from the {11-20} plane is used as the first growth surface. Using the exposed first seed crystal, a SiC single crystal is grown on the first growth surface to produce a first growth crystal,
n = 2, 3,. . . In the (N-1) th intermediate growth step, a surface inclined by 45 to 90 ° from the (n-1) th growth surface and inclined by 60 to 90 ° from the {0001} surface is defined as the nth growth surface. An n-th crystal is produced from the (n-1) -th growth crystal, and an SiC single crystal is grown on the n-th growth surface of the n-th crystal to produce an n-th growth crystal.
In the seed crystal manufacturing step, a SiC seed crystal is characterized in that a plane having an offset angle of ± 20 ° or less from the {0001} plane of the (N-1) -th grown crystal is exposed as a final growth plane.   7. The container according to claim 6, wherein in the first growth step and the intermediate growth step, the surface of the seed crystal is thermally etched or grown at a growth temperature or a temperature within ± 400 ° C. from the growth temperature. A SiC seed crystal characterized by performing a preliminary step of introducing an etching gas into the substrate, and then performing growth by shifting to a growth temperature.   8. The SiC seed crystal according to claim 6, wherein a sublimation reprecipitation method is used for the growth of the SiC single crystal on the various crystals.   9. The SiC seed crystal according to claim 6, wherein the various crystals have a thickness of 1 mm or more.

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