Patent ID: 8709854

Claim:
A method for forming an image sensor comprising: providing a semiconductor substrate having a sensor array region and a periphery region and having a front side surface and an opposing back side surface; forming a bottom anti-reflective coating (BARC) over the back side surface of the semiconductor substrate to a first thickness, over the sensor array region and the periphery region; forming a first dielectric layer over the BARC; forming a metal shield over the first dielectric layer; selectively removing the metal shield from over the sensor array region; selectively removing the first dielectric layer from over the sensor array region, wherein a portion of the first thickness of the BARC is also removed and a remainder of the first thickness of the BARC remains, during the selectively removing the first dielectric layer; forming a second dielectric layer over the remainder of the first thickness of the BARC and over the metal shield over the periphery region; and forming a passivation layer over the second dielectric layer.