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:
Aug. 27, 2002
Filed:
Dec. 13, 1999
Hiroyuki Ota, Tsurugashima, JP;
Atsushi Watanabe, Tsurugashima, JP;
Toshiyuki Tanaka, Tsurugashima, JP;
Pioneer Corporation, Tokyo, JP;
Abstract
A semiconductor light emitting device having multi-layer structure of group-3 nitride-based semiconductors is disclosed. The light emitting device has lower density of threading dislocation extending from a boundary of a crystal substrate through the multi-layer structure, thereby obtaining good luminescence characteristics. The nitride semiconductor light emitting device has the multi-layer structure. The multi-layer structure comprises a first crystal layer containing substantially pyramidal crystal grains, each of grains has a crystal face non-parallel to a surface of the substrate, and the pyramidal crystal grains are distributed at random like islands. The structure further comprises a second crystal layer formed on the first crystal layer with a compound having a different lattice constant from that of the first crystal layer. The second crystal layer smoothes a surface of the first crystal layer parallel to the surface of the substrate.