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. 03, 2009
Filed:
Jun. 26, 2006
Christopher Harris, Taby, SE;
Thomas Gehrke, Manassas Park, VA (US);
T. Warren Weeks, Jr., Charleston, SC (US);
Cem Basceri, Reston, VA (US);
Elif Berkman, Reston, VA (US);
Christopher Harris, Taby, SE;
Thomas Gehrke, Manassas Park, VA (US);
T. Warren Weeks, Jr., Charleston, SC (US);
Cem Basceri, Reston, VA (US);
Elif Berkman, Reston, VA (US);
Cree, Inc., Durham, NC (US);
Abstract
A method of compensating resistivity of a near-surface region of a substrate includes epitaxially growing a buffer layer on the substrate, wherein the buffer is grown as having a dopant concentration as dependent on resistivity and conductivity of the substrate, so as to deplete residual or excess charge within the near-surface region of the substrate. The dopant profile of the buffer layer be smoothly graded, or may consist of sub-layers of different dopant concentration, to also provide a highly resistive upper portion of the buffer layer ideal for subsequent device growth. Also, the buffer layer may be doped with carbon, and aluminum may be used to getter the carbon during epitaxial growth.