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. 30, 1995
Filed:
Feb. 16, 1994
Applicant:
Inventors:
Sureshchandra M Ojha, Harlow, GB;
Stephen J Clements, Stansted, GB;
Assignee:
Northern Telecom Limited, Montreal, CA;
Primary Examiner:
Int. Cl.
CPC ...
H01L / ; B44C / ;
U.S. Cl.
CPC ...
1566431 ; 252 791 ; 437129 ; 437234 ;
Abstract
A process for plasma etching a compound semiconductor heterostructure, e.g. to fabricate a ridge laser on a wavelength demultiplexer comprises anisotropic etching of the semiconductor by exposure to a plasma incorporating methane, hydrogen and oxygen. The oxygen content of the plasma is derived from a gaseous precursor such as carbon dioxide or nitrous oxide.