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:
Sep. 30, 2003
Filed:
Mar. 28, 2001
Johji Nishio, Tokyo, JP;
Masayuki Ishikawa, Kanagawa, JP;
Kabsuhiki Kaisha Toshiba, Kawasaki, JP;
Abstract
The present invention provides a method for preparing epitaxial-substrate, for growing a multilayered structure of GaN based semiconductor layers on the epitaxial-substrate so as to construct a semiconductor device such as blue-emitting laser diode and LED. The method for preparing the epitaxial-substrate encompasses (a) growing a first GaN based semiconductor layer on a bulk-substrate; (b) growing an InGaN based semiconductor layer on the first GaN based semiconductor layer; (c) growing a second GaN based semiconductor layer on the InGaN based semiconductor layer; and (d) separating the second GaN based semiconductor layer from the first GaN based semiconductor layer to provide the epitaxial-substrate. The epitaxial-substrate having a high crystallographic perfection and an excellent surface morphology is obtained simply and in a short time. The defect density of the single crystalline GaN based semiconductor layer film grown on the epitaxial-substrate is greatly reduced.