Back-side illuminated image sensor with a junction insulation

US8963273B2 · kind B2 · utility

Assignees

• STMicroelectronics SA
• STMicroelectronics (Crolles 2) SAS · FR

Inventors

• Michel Marty · Buc, FR
• Francois Roy · Seyssinet-Pariset, FR
• Jens Prima · Gehrde, DE

Key dates

• Filing date: Apr 7, 2014
• Grant date: Feb 24, 2015
• Expiry date: Apr 7, 2034

Classification

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

Abstract

A method for forming a back-side illuminated image sensor, including the steps of: a) forming, from the front surface, doped polysilicon regions, of a conductivity type opposite to that of the substrate, extending in depth orthogonally to the front surface and emerging into the first layer; b) thinning the substrate from its rear surface to reach the polysilicon regions, while keeping a strip of the first layer; c) depositing, on the rear surface of the thinned substrate, a doped amorphous silicon layer, of a conductivity type opposite to that of the substrate; and d) annealing at a temperature capable of transforming the amorphous silicon layer into a crystallized layer.