METHOD OF MANUFACTURING SiC INGOT

Patent metadata

Field	Value
Publication number	US-2019194823-A1
Application number	US-201816225260-A
Country	US
Kind code	A1
Filing date	Dec 19, 2018
Priority date	Dec 22, 2017
Publication date	Jun 27, 2019
Grant date	—

Abstract

A method of measuring a SiC ingot includes a measuring step of measuring a curving direction of an atomic arrangement plane of a SiC single crystal at least along a first direction passing through a center in plan view and a second direction intersecting with the first direction to obtain a shape of the atomic arrangement plane; and a crystal growth step of performing crystal growth using the SiC single crystal as a seed crystal, in which in a case where the shape of the atomic arrangement plane measured in the measuring step is a saddle type, a crystal growth condition in the crystal growth step is set such that a convexity of a second growth front at the end of crystal growth becomes larger than a convexity of a first growth front when an amount of crystal growth in the center of the seed crystal is 7 mm.

First claim

What is claimed is:

1 . A method of manufacturing a SiC ingot, comprising:
a measuring step of measuring a curving direction of an atomic arrangement plane of a SiC single crystal at least along a first direction passing through a center in plan view and a second direction intersecting with the first direction so as to obtain a shape of the atomic arrangement plane; and a crystal growth step of performing crystal growth using the SiC single crystal as a seed crystal, wherein in a case where the shape of the atomic arrangement plane measured in the measuring step is a saddle type that the curving direction of the atomic arrangement plane is different in the first direction and the second direction, a crystal growth condition in the crystal growth step is set such that a convexity of a second growth front at the end of crystal growth becomes larger than a convexity of a first growth front when the amount of crystal growth in the center of the seed crystal is 7 mm.

2 . The method of manufacturing a SiC ingot according to claim 1 ,
wherein the crystal growth condition in the crystal growth step is set such that the convexity is gradually increased toward second growth front from the first growth front.

3 . The method of manufacturing a SiC ingot according to claim 1 ,
wherein in the crystal growth step, a height difference of the growth front is gradually increased toward the second growth front from the first growth front.

4 . The method of manufacturing a SiC ingot according to claim 2 ,
wherein in the crystal growth step, a height difference of the growth front is gradually increased toward the second growth front from the first growth front.

5 . The method of manufacturing a SiC ingot according to claim 1 ,
wherein a difference between a height difference of the first growth front and a growth front height difference of the second growth front is 0.5 mm to 4.0 mm.

6 . The method of manufacturing a SiC ingot according to claim 2 ,
wherein a difference between a height difference of the first growth front and a growth front height difference of the second growth front is 0.5 mm to 4.0 mm.

7 . The method of manufacturing a SiC ingot according to claim 3 ,
wherein a difference between a height difference of the first growth front and a growth front height difference of the second growth front is 0.5 mm to 4.0 mm.

8 . The method of manufacturing a SiC ingot according to claim 1 ,
wherein the measuring step of obtaining the shape of the atomic arrangement plane includes
a first substep of preparing the SiC single crystal, or the SiC single crystal that is sliced, as a sample, determining a diffraction plane at two points which are on a straight line passing through a center of the sample in plan view and at the same distance from the center, and performing XRD so as to obtain a difference Δθ between peak angles of X-ray diffraction as a difference between inclinations of the atomic arrangement planes at two points,
a second substep of repeating the same operation as that in the first substep by changing the two points of positions one or more times,
a third substep of obtaining a radius of curvature of the atomic arrangement plane from the obtained 2 or more Δθ and 2 or more distances from the center of the sample, and
a fourth substep of obtaining an amount of curvature of the atomic arrangement plane from the obtained radius of curvature of the atomic arrangement plane and a radius of the sample.

9 . The method of manufacturing a SiC ingot according to claim 8 , further comprising:
a fifth substep of performing the first to fourth substeps in both the first direction and the second direction intersecting with the first direction.

10 . The method of manufacturing a SiC ingot according to claim 9 , further comprising:
a sixth substep of determining whether or not a curving direction of the atomic arrangement plane is different between the first direction and the second direction by evaluating the result of the fifth substep.

11 . The method of manufacturing a SiC ingot according to claim 1 ,
wherein the measuring step of obtaining the shape of the atomic arrangement plane includes
a first substep of preparing the SiC single crystal, or the sliced SiC single crystal that is sliced, as a sample, determining a diffraction plane at two points which are on a straight line passing through a center of the sample in plan view and at the same distance from the center, and performing XRD so as to obtain a difference Δθ between peak angles of X-ray diffraction as a difference between inclinations of the atomic arrangement planes at two points,
a second substep of repeating the same operation as that in the first substep by changing the two points of positions one or more times,
a third substep of obtaining each of relative atom positions of the atomic arrangement plane from the each obtained Δθ and each distance from the center of the sample, and
fourth substep of evaluating each obtained atom position of the atomic arrangement plane.

12 . The method of manufacturing a SiC ingot according to claim 11 , further comprising:
a fifth substep of performing the first to fourth substeps in both the first direction and the second direction intersecting with the first direction.

13 . The method of manufacturing a SiC ingot according to claim 12 , further comprising:
a sixth substep of determining whether or not a curving direction of the atomic arrangement plane is different between the first direction and the second direction by evaluating the result of the fifth substep.

14 . The method of manufacturing a SiC ingot according to claim 1 ,
wherein the crystal growth step is a growth step of the SiC ingot, wherein the SiC ingot includes a c-plane growth region and a lateral growth region, and wherein the convexity is a value obtained by dividing a difference between an amount of crystal growth of the growth front of the SiC ingot at a center line C passing through the center of the seed crystal and extending in a stacking direction and an amount of crystal growth of the growth front of the SiC ingot at a boundary between the c-plane growth region and the lateral growth region, by a diameter of the growth front.

Assignees

• Showa Denko Kk

Inventors

• Fujikawa Yohei

Classifications

• H10P74/203

  Structural properties, e.g. testing or measuring thicknesses, line widths, warpage, bond strengths or physical defects · CPC title

• H10P14/3408

  Silicon carbide · CPC title

• G01N23/20

  by using diffraction of the radiation by the materials, e.g. for investigating crystal structure; by using scattering of the radiation by the materials, e.g. for investigating non-crystalline materials; by using reflection of the radiation by the materials · CPC title

• C30B29/36 Primary

  Carbides · CPC title

• C30B23/02

  Epitaxial-layer growth · CPC title