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:
Feb. 23, 1999
Filed:
May. 05, 1997
Applicant:
Inventors:
Richard H Hopkins, Export, PA (US);
Godfrey Augustine, Pittsburgh, PA (US);
H McDonald Hobgood, Murrysville, PA (US);
Assignee:
Northrop Grumman Corporation, Los Angeles, CA (US);
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
H01L / ;
U.S. Cl.
CPC ...
117105 ; 117 88 ; 117104 ;
Abstract
A method of growing 4-H polytype silicon carbide crystals in a physical vapor transport system where the surface temperature of the crystal is maintained at less than about 2160.degree. C. and the pressure inside the PVT system is decreased to compensate for the lower growth temperature.