Patent ID: 9534317
Date: 2017-01-03
CPC Classifications: C30B,Y10T

Claim:
1. A seed crystal for SiC single-crystal growth, comprising: a facet formation region containing a {0001}-plane uppermost portion; and n (n>=3) planes enclosing the periphery of the facet formation region, wherein: the facet formation region includes a region ranging from the center of gravity of the {0001}-plane uppermost portion to any point corresponding to a radius r being R/5 where R is a diameter of a circumscribed circle of the seed crystal for SiC single-crystal growth; the seed crystal for SiC single-crystal growth satisfies the relationships represented by formulas (a) to (c), where C k is an offset angle of a k-th plane, B k k-1 is an angle defined by an offset downstream direction of the k-th plane and a (k−1)-th ridge line, and B k k is an angle defined by the offset downstream direction of the k-th plane and a k-th ridge line; by satisfying the relationships represented by formulas (a) and (b), an angle defined by the (k−1)-th ridge line and the {0001} plane is 2.3 degrees or more so that no c-plane facet is formed on the (k−1)-th ridge line and an angle defined by the k-th ridge line and the {0001} plane is 2.3 degrees or more so that no c-plane facet is formed on the k-th ridge line; and a diameter of the circumscribed circle of the seed crystal for SiC single-crystal growth is 100 mm or more.