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:
Jan. 01, 1991
Filed:
Aug. 03, 1989
Andrew Nelson, Felixstowe, GB;
Simon Cole, Martlesham Heath, GB;
Michael J Harlow, Ipswich, GB;
Stanley Y Wong, Ipswich, GB;
British Telecommunications Public Limited Company, London, GB;
Abstract
It has been found that layers which include arsenic and/or zinc can have an adverse effect upon optoelectronic semiconductor devices such as lasers. This is reduced by treatments in which arsenic and zinc are excluded. Preferably the substrate is cooled from reaction temperature in the presence of a mixture of hydrogen and PH.sub.3 (replacing AsH.sub.3 and/or Zn(CH.sub.3).sub.2 used to grow the final layer). Alternatively, devices have a contact layer of heavily p-type gallium indium arsenide are improved by the deposition of a protective layer of indium phosphide. This layer is removed immediately before metalization. Even though the protective layer is not present in the final product it has a beneficial effect.