Photodiode structure for image sensor

US12349492B2 · kind B2 · utility

Assignee

• TAIWAN SEMICONDUCTOR MANUFACTURING COMPANY LTD. · TW

Inventors

• Min-Ying Tsai · Kaohsiung, TW
• Ching-I Li · Tainan, TW

Key dates

• Filing date: Mar 30, 2021
• Grant date: Jul 1, 2025
• Expiry date: Nov 25, 2041

Classification

• Technology area (CPC H): Electricity
• CPC primary: H10F39/811

Abstract

The present disclosure relates to an image sensor having an epitaxial deposited photodiode structure surrounded by an isolation structure, and an associated method of formation. In some embodiments, a first epitaxial deposition process is performed to form a first doped EPI layer over a substrate. The first doped EPI layer is of a first doping type. Then, a second epitaxial deposition process is performed to form a second doped EPI layer on the first doped EPI layer. The second doped EPI layer is of a second doping type opposite from the first doping type. Then, an isolation structure is formed to separate the first doped EPI layer and the second doped EPI layer as a plurality of photodiode structures within a plurality of pixel regions. The plurality of photodiode structures is configured to convert radiation that enters from a first side of the image sensor into an electrical signal.