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 method of manufacturing an image sensor, the method comprising:
providing a semiconductor substrate having a sensor array region and a periphery region and having a front side and an opposing back side surface; forming a bottom anti-reflective coating (BARC) layer over the back side surface of the semiconductor substrate to a first thickness over the sensor array region and the periphery region; forming a metal shield layer over the BARC layer; selectively removing portions of the metal shield layer from over the sensor array region to form a metal shield grid over the sensor array region; selectively removing portions of the BARC layer exposed by the selectively removing the metal shield layer, wherein a portion of the first thickness of the BARC layer is also removed and a remainder of the first thickness of the BARC layer remains during the selectively removing the portions of the metal shield layer; forming a first dielectric layer within the metal shield grid over the sensor array region and over a remainder of the first thickness of the BARC layer over the periphery region; and forming a second dielectric layer within the metal shield grid, the second dielectric layer having a different refractive index than the first dielectric layer.