Epitaxial growth of germanium photodetector for CMOS imagers

US7008813B1 · kind B1 · utility

Assignee

• Sharp Laboratories of America, Inc. · US

Inventors

• Jong-Jan Lee · Camas, US
• Jer-Shen Maa · Vancouver, US
• Douglas J. Tweet · Camas, US
• Sheng Teng Hsu · Camas, US

Key dates

• Filing date: Feb 28, 2005
• Grant date: Mar 7, 2006
• Expiry date: Feb 28, 2025

Classification

• Technology area (CPC Y): Emerging Cross-Sectional Technologies
• CPC primary: Y10S148/101

Abstract

A method of fabricating a germanium photodetector includes preparing a silicon wafer as a silicon substrate; depositing a layer of silicon nitride on the silicon substrate; patterning and etching the silicon nitride layer; depositing a first germanium layer on the silicon nitride layer; patterning and etching the germanium layer wherein a portion of the germanium layer is in direct physical contact with the silicon substrate; depositing a layer of silicon oxide on the germanium layer wherein the germanium layer is encapsulated by the silicon oxide layer; annealing the structure at a temperature wherein the germanium melts and the other layers remain solid; growing a second, single-crystal layer of germanium on the structure by liquid phase epitaxy; selectively removing the silicon oxide layer; and completing the germanium photodetector.