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. 08, 1990
Filed:
Aug. 24, 1989
Jaya Bilakanti, Teaneck, NJ (US);
Edward J Laskowski, Scotch Plains, NJ (US);
American Telephone and Telegraph Company, New York, NY (US);
Abstract
An etching process is described for etching aluminum containing III-V semiconductor compounds. The etch solution contains dichromate ion in acid aqueous solution in which the acid is either phosphoric acid or sulfuric acid. The etch solution is highly selective in that it etches the aluminum containing III-V semiconductor compounds without etching significantly other III-V semiconductor compounds not containing aluminum exposed to the same etching solution. the etching process is extremely useful in fabricating a variety of III-V semiconductor devices including heterojunction bipolar transistors, heterojunction field effect transistors and self-enhanced electro optic devices.