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:
Oct. 08, 2002
Filed:
Jun. 03, 1999
Masayoshi Ashida, Kyoto, JP;
Satoshi Uchida, Kyoto, JP;
Rohm Co., Ltd., Kyoto, JP;
Abstract
A semiconductor laser element is made by forming a lower clad layer, an active layer and an upper clad layer sequentially one on top of another on a semiconductor substrate, forming an etching stop layer completely over the upper clad layer, forming a contact layer on the etching stop layer, and etching portions of the contact layer to form steps. The etching stop layer has a slower etching speed than the contact layer against the etching liquid used for forming the steps by etching portions of the contact layer. An upper electrode is formed on the contact layer and a lower electrode is formed on the bottom surface of the substrate. The steps provide areas in the active layer where a current will not flow through.