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:
Nov. 23, 2004
Filed:
Feb. 07, 2003
Sharp Kabushiki Kaisha, Osaka, JP;
Abstract
The semiconductor light emitting device has a gallium nitride base compound semiconductor layer expressed by a general formula of In Ga Al N (x+y+z=1, 0≦x≦1, 0≦y≦1, 0≦z≦1). A second intermediate layer is provided between a GaN layer and a light emitting layer, and the second intermediate layer has a lattice constant closer to that of the light emitting layer than that of the GaN layer. As such, when a substrate such as Si substrate having a smaller coefficient of thermal expansion than the nitride semiconductor film is employed, occurrence of cracks is prevented and good crystallinity of the nitride semiconductor film is assured, and accordingly, a long-life and high-luminance nitride base semiconductor light emitting device is obtained.