Backside imaging through a doped layer

US7479686B2 · kind B2 · utility

Assignee

• INTEVAC, INC. · US

Inventors

• Kenneth Costello · Union City, US
• Kevin Fairbairn · Los Gatos, US
• David Ward Brown · Lansdale, US
• Yun H. Chung · Toledo, US
• Patricia Gober · Santa Clara, US
• Edward Yin · Cupertino, US

Key dates

• Filing date: Nov 30, 2005
• Grant date: Jan 20, 2009
• Expiry date: Jul 24, 2027

Classification

• Technology area (CPC H): Electricity
• CPC primary: H10F39/8057

Abstract

Backthinning in an area selective manner is applied to CMOS imaging sensors 12 for use in electron bombarded active pixel array devices. A further arrangement results in an array of collimators 51 aligned with pixels 42 or groups of pixels of an active pixel array providing improved image contrast of such image sensor. Provision of a thin P-doped layer 52 on the illuminated rear surface provides both a diffusion barrier resulting in improved resolution and a functional shield for reference pixels. A gradient in concentration of P-doped layer 52 optimizes electron collection at the pixel array.