Patent ID: 8766391

Claim:
A backside illuminated image sensor comprising: an array of photosensitive regions disposed within a frontside portion of a substrate; a backside surface to receive light; an interconnect portion on the frontside portion of the substrate; a first material coupled between the backside surface and the array of photosensitive regions, the first material to receive the light, at least some of the light to free electrons in the first material; and an array of second material portions, the array of the second material portions coupled between the backside surface and the first material, each second material portion of the array corresponding to one of the photosensitive regions, each second material portion of the array comprising one of a doped semiconductor material that is more heavily doped than the first material and a metal capable of generating a hole accumulation region in the first material, wherein each second material portion of the array has a same thickness, wherein the photosensitive regions are of a first dopant type, wherein the substrate is of a second dopant type different than the first dopant type, wherein the second material portions are of the second dopant type.