Patent ID: 9401380
Filing Date: 2016-07-26
CPC Classification: H01L,Y02E,Y02P

Claim Text:
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.