Continuous amorphous silicon layer sensors using doped poly-silicon back contact

US6288435A · kind A · utility

Assignee

• Xerox Corporation · US

Inventors

• Ping Mei · Palo Alto, US
• Jeng Ping Lu · San Jose, US
• Francesco Lemmi · Roma, IT
• Robert A. Street · Palo Alto, US
• James B. Boyce · Los Altos, US

Key dates

• Filing date: Dec 28, 1999
• Grant date: Sep 11, 2001
• Expiry date: Dec 28, 2019

Classification

• Technology area (CPC Y): Emerging Cross-Sectional Technologies
• CPC primary: Y02E10/548

Abstract

A method and apparatus for reducing vertical leakage current in a high fill factor sensor array is described. Reduction of vertical leakage current is achieved by eliminating Schottky junction interfaces that occur between metal back contacts and intrinsic amorphous silicon layers. One method of eliminating the Schottky junction uses an extra wide region of N doped amorphous silicon to serve as a buffer between the metal back contact and the intrinsic amorphous silicon layer. Another method of eliminating the Schottky junction completely replaces the metal back contact and the N doped amorphous silicon layer with a substitute material such as N doped poly-silicon.