Three-dimensional island pixel photo-sensor

US6720595B2 · kind B2 · utility

Assignee

• International Business Machines Corporation · US

Inventors

• Lawrence A. Clevenger · Saratoga Springs, US
• Louis L. Hsu · Fishkill, US
• Carl Radens · Lagrangeville, US
• Li-Kong Wang · Montvale, US
• Kwong Hon Wong · Wappingers Falls, US

Key dates

• Filing date: Aug 6, 2001
• Grant date: Apr 13, 2004
• Expiry date: Aug 6, 2021

Classification

• Technology area (CPC H): Electricity
• CPC primary: H10F39/807

Abstract

A method and structure for a photodiode array comprising a plurality of photodiode cores, light sensing sidewalls along an exterior of the cores, logic circuitry above the cores, trenches separating the cores, and a transparent material in the trenches is disclosed. With the invention, the sidewalls are perpendicular to the surface of the photodiode that receives incident light. The light sensing sidewalls comprise a junction region that causes electron transfer when struck with light. The sidewalls comprise four vertical sidewalls around each island core. The logic circuitry blocks light from the core so light is primarily only sensed by the sidewalls.