Transparent ohmic contacts for Schottky diode optical detectors on thin and inverted epitaxial layers

US5639673A · kind A · utility

Assignee

• United States of America as represented by the Secretary of the Air Force · US

Inventors

• Kenneth Vaccaro · Acton, US
• Eric A. Martin · Medford, US
• Stephen Spaziani · Nashua, US
• Andrew Davis · Boston, US

Key dates

• Filing date: Jun 8, 1995
• Grant date: Jun 17, 1997
• Expiry date: Jun 8, 2015

Classification

• Technology area (CPC H): Electricity
• CPC primary: H10F77/413

Abstract

An InP buffer layer is first formed upon an InP substrate; a thin layer of heavily doped InGaAs, a thick layer of light absorbing InGaAs, and a thin layer of InAlAs are thereafter sequentially grown upon the InP buffer layer. A light reflective Schottky barrier metallic layer is then applied to the InAlAs layer and the resulting device is inverted and affixed to a newly provided substrate, to thus shield and protect the sensitive Schottky contact. The InP substrate layers are thereafter removed and the now exposed thin, heavily doped InGaAs layer is coated with a transparent, electrically conductive layer of Indium-tin-oxide.