The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jul. 21, 2009
Filed:
Dec. 08, 2004
Applicants:
Adrian Powell, Cary, NC (US);
Valeri F. Tsvetkov, Durham, NC (US);
Mark Brady, Carrboro, NC (US);
Robert T. Leonard, Raleigh, NC (US);
Inventors:
Adrian Powell, Cary, NC (US);
Valeri F. Tsvetkov, Durham, NC (US);
Mark Brady, Carrboro, NC (US);
Robert T. Leonard, Raleigh, NC (US);
Assignee:
Cree, Inc., Durham, NC (US);
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
C30B 23/00 (2006.01); H01L 29/04 (2006.01);
U.S. Cl.
CPC ...
Abstract
The invention is an improvement in the method of producing a high quality bulk single crystal of silicon carbide in a seeded sublimation system. In a first embodiment, the improvement comprises reducing the number of macrosteps in a growing crystal by incorporating a high concentration of nitrogen atoms in the initial one (1) millimeter of crystal growth.