Seed crystal for SiC single-crystal growth, SiC single crystal, and method of manufacturing the SiC single crystal

摘要

A seed crystal for SiC single-crystal growth includes a facet formation region containing a {0001}-plane uppermost portion and n (n>=3) planes provided enclosing the periphery of the facet formation region. The seed crystal for SiC single-crystal growth satisfies the relationships represented by formula (a): Bkk-1<=cos−1(sin(2.3 degrees)/sin Ck), formula (b): Bkk<=cos−1(sin(2.3 degrees)/sin Ck), and formula (c): min(Ck)<=20 degrees. In the formulas, Ck is an offset angle of a k-th plane, Bkk-1 is an angle defined by an offset downstream direction of the k-th plane and a (k−1)-th ridge line, and Bkk is an angle defined by the offset downstream direction of the k-th plane and a k-th ridge line.

主权项

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),
Bkk-1<=cos−1(sin(2.3 degrees)/sin Ck)  (a),Bkk<=cos−1(sin(2.3 degrees)/sin Ck)  (b),min(Ck)<=20 degrees  (c),where Ck is an offset angle of a k-th plane, Bkk-1 is an angle defined by an offset downstream direction of the k-th plane and a (k−1)-th ridge line, and Bkk 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.