Optical field-effect transistor with improved sensitivity

US5567973A · kind A · utility

Assignee

• The United States of America as represented by the Secretary of the Army · US

Inventors

• Arthur Paolella · Howell, US
• Bahram Nabet · Philadelphia, US

Key dates

• Filing date: Aug 4, 1995
• Grant date: Oct 22, 1996
• Expiry date: Aug 4, 2015

Classification

• Technology area (CPC H): Electricity
• CPC primary: H10F30/2843

Abstract

An FET or MESFET having a semiconductor optically transparent gate. A substrate having a doped channel placed thereon together with a source and a drain with a semiconductor gate formed therebetween may be manufactured using conventional semiconductor manufacturing techniques. The optically transparent highly doped semiconductor gate forms an n+-n junction with the n-type doped channel. This junction is modulated or changed by an optical signal causing a photovoltaic effect that reduces the barrier potential at the n+-n junction resulting in a depletion of the accumulation region. This results in increased flow of current in the doped channel. The transparent highly doped semiconductor gate increases performance of the FET or MESFET optical detector. This is an improvement over conventional metal semiconductor field-effect transistor (MESFET) technology, and can be applied to microwave monolithic integrated circuits (MMIC).