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. 07, 2002
Filed:
Jul. 07, 1999
Mitsuhiko Ogihara, Tokyo, JP;
Yukio Nakamura, Tokyo, JP;
Masumi Taninaka, Tokyo, JP;
Hiroshi Hamano, Tokyo, JP;
Oki Data Corporation, Tokyo, JP;
Abstract
In one aspect of the invention, a light-emitting semiconductor device has a light-emitting layer with a certain bandgap energy, an upper cladding layer with a higher bandgap energy, a first diffusion area extending into the light-emitting layer, a second diffusion area extending only into the upper cladding layer, and an electrode making contact with the second diffusion area, without covering any part of the first diffusion area. The second diffusion area conducts current to the first diffusion area, where light is emitted from a pn junction in the light-emitting layer. In another aspect of the invention, a semiconductor contact layer is provided to assure ohmic contact with the electrode, and the semiconductor contact layer is removed from the light-emitting area, avoiding absorption of light.