Patent ID: 9257326
Filing Date: 2016-02-09
CPC Classification: H01L

Claim Text:
1. A method of making a backside illuminated image sensor, the method comprising: forming a first isolation structure in a pixel region of a substrate, wherein a bottom of the first isolation structure is exposed at a back surface of the substrate; forming a second isolation structure in a peripheral region of the substrate, wherein the second isolation structure has a depth less than a depth of the first isolation structure; forming an implant region adjacent to at least a portion of sidewalls of the first isolation structure, wherein the portion of the sidewalls is located closer to the back surface than a front surface of the substrate, wherein the second isolation structure is free of the implant region; and forming a third isolation structure between a sensor element adjacent to the peripheral region and an active device in the peripheral region adjacent to a pixel region, wherein a depth of the third isolation structure is equal to the depth of the first isolation structure.