Enhanced trench isolation structure

US11784204B2 · kind B2 · utility

Assignee

• TAIWAN SEMICONDUCTOR MANUFACTURING COMPANY LTD. · TW

Inventors

• Min-Ying Tsai · Kaohsiung, TW
• Cheng-Te Lee
• Rei-Lin Chu · Hsinchu, TW
• Ching-I Li · Tainan, TW
• Chung-Yi Yu · Baoshan, TW

Key dates

• Filing date: Oct 19, 2020
• Grant date: Oct 10, 2023
• Expiry date: Jun 3, 2041

Classification

• Technology area (CPC Y): Emerging Cross-Sectional Technologies
• CPC primary: Y02P70/50

Abstract

The present disclosure relates to an image sensor comprising a substrate. A photodetector is in the substrate. A trench is in the substrate and is defined by sidewalls and an upper surface of the substrate. A first isolation layer extends along the sidewalls and the upper surface of the substrate that define the trench. The first isolation layer comprises a first dielectric material. A second isolation layer is over the first isolation layer. The second isolation layer lines the first isolation layer. The second isolation layer comprises a second dielectric material. A third isolation layer is over the second isolation layer. The third isolation layer fills the trench and lines the second isolation layer. The third isolation layer comprises a third material. A ratio of a first thickness of the first isolation layer to a second thickness of the second isolation layer is about 0.17 to 0.38.