Backside structure and methods for BSI image sensors

摘要

A back side image sensor and method of manufacture are provided. In an embodiment a bottom anti-reflective coating is formed over a substrate, and a metal shield layer is formed over the bottom anti-reflective coating. The metal shield layer is patterned to form a grid pattern over a sensor array region of the substrate, and a first dielectric layer and a second dielectric layer are formed to at least partially fill in openings within the grid pattern.

主权项

1. A back side image sensor comprising:
a semiconductor substrate with a first side and a second side, the semiconductor substrate comprising a pixel region and a periphery region; a BARC layer located on the second side, the BARC layer having a first region with a first thickness in the periphery region and a second region with a second thickness in the pixel region, the second thickness being less than the first thickness; a metal shield grid located over the BARC layer, wherein the metal shield grid comprises a first opening through the metal shield grid, the first opening located over the second region; a first dielectric layer covering sidewalls of the first opening, the first dielectric layer having a first refractive index; and a second dielectric layer adjacent to the first dielectric layer, the second dielectric layer having a second refractive index different from the first refractive index.