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. 18, 1993
Filed:
Mar. 02, 1992
Paul R Berger, Summit, NJ (US);
Alfred Y Cho, Summit, NJ (US);
Niloy K Dutta, Colonia, NJ (US);
John Lopata, North Plainfield, NJ (US);
Henry M O'Bryan, Jr, Plainfield, NJ (US);
Deborah L Sivco, Warren, NJ (US);
George J Zydzik, Columbia, NJ (US);
AT&T Bell Laboratories, Murray Hill, NJ (US);
Abstract
This invention pertains to a p-i-n In.sub.0.53 Ga.sub.0.47 As photodiode having an optically transparent composite top electrode consisting of a thin semitransparent metal layer from 10 to 40 nm thick and a transparent cadmium tin oxide (CTO) layer from 90 to 600 nm thick. The metal layer makes a non-alloyed ohmic contact to the semiconductor surface, acts as a barrier between the semiconductor and the CTO preventing oxidation of the semiconductor from the O.sub.2 in the plasma during reactive magnetron sputtering of the CTO layer, and prevents formation of a p-n junction between the semiconductor and CTO. The CTO functions as the n or p contact, an optical window and an anti-reflection coating. The top electrode also avoids shadowing of the active layer by the top electrode, thus allowing greater collection of incident light. Since the top electrode is non-alloyed, inter-diffusion into the i-region is not relevant, which avoids an increased dark current.