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:
Jul. 13, 1993
Filed:
Jul. 25, 1991
Matsushita Electric Industrial Co., Ltd., Osaka, JP;
Abstract
An n-InP buffer layer 102, an InGaAsP active layer 103, a p-InP cladding layer 104 and a p-InGaAsP surface protective layer 105 are successively epitaxially grown on an n-InP substrate 101 having a (100) plane as a main plane. An etching mask 106, an insulating film, is formed in a stripe in the <011> direction by photolithography and dry etching. Using a solution comprising a mixture of hydrochloric acid, oxygenated water and acetic acid, the n-InP buffer layer 102 is etched to a depth lower than the p-InP cladding layer 103, to form a mesa stripe 107. Next, the insulating film 106 is removed and the p-InGaAsP surface protective layer 105 is removed using a solution comprising a mixture of sulfuric acid and oxygenated water. Thereafter, InP current blocking layers 108 and 109 are selectively formed at the regions other than the mesa stripe 107 by the liquid-phase epitaxial growth. Thus, a buried heterostructure semiconductor laser is fabricated, having good laser characteristics and a high reliability.