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:
May. 11, 2010
Filed:
Mar. 19, 2008
Kei Kosaka, Nagoya, JP;
Shigeaki Sumiya, Handa, JP;
Tomohiko Shibata, Akita, JP;
NGK Insulators, Ltd., Nagoya, JP;
Abstract
A method for preparing an AlGaN crystal layer with good surface flatness is provided. A surface layer of AlN is epitaxially formed on a c-plane sapphire single crystal base material by MOCVD method, and the resulting laminated body is then heated at a temperature of 1300° C. or higher so that a template substrate applying in-plane compressive stress and having a surface layer flat at a substantially atomic level is obtained. An AlGaN layer is formed on the template substrate at a deposition temperature higher than 1000° C. by an MOCVD method that includes depositing alternating layers of a first unit layer including a Group III nitride represented by the composition formula AlGaN (0≦x≦1) and a second unit layer including a Group III nitride represented by the composition formula AlGaN (0≦y≦1 and y≠x) such that the AlGaN layer has a superlattice structure.
Data source: USPTO (United States Patent and Trademark Office) public patent records. Weekly synchronization. How IDiyas builds this profile