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. 19, 2002
Filed:
Apr. 27, 2000
Atsushi Yoshinaga, Saitama, JP;
Junichi Yamamoto, Saitama, JP;
Showa Denko Kabushiki Kaisha, Tokyo, JP;
Abstract
The present invention provides an epitaxial wafer comprising, on a p-type GaAs single-crystal substrate, a first p-type layer; a p-type cladding layer; a p-type active layer; and an n-type cladding layer, wherein the n-type cladding layer has a carrier concentration of 1×10 to 1×10 cm ; a sulfur concentration of 3×10 atoms/cm or less; and a thickness of 20-50 &mgr;m. The maximum silicon concentration in the portion of the p-type cladding layer within 2 &mgr;m of the interface between the p-type cladding layer and the first p-type layer is less than 1×10 atoms/cm ; the concentration of carbon, sulfur, or oxygen in the first p-type layer is less than 1×10 atoms/cm ; the p-type cladding layer has a thickness of 50-80 &mgr;m; the first p-type layer has a carrier concentration of 3×10 to 1×10 cm ; and the n-type cladding layer contains germanium at a concentration of 3×10 cm or less. Thus, there can be produced an epitaxial wafer for fabricating an infrared LED exhibiting high emitted-light intensity with small variation.