Patent ID: 7989859

Claim:
A backside illuminated imaging sensor, comprising: a semiconductor layer having a front surface and a back surface, the semiconductor layer having an imaging pixel that includes a photodiode region formed within the semiconductor layer; a metal interconnect layer electrically coupled to the photodiode region; a protection oxide disposed on the front surface of the semiconductor layer; a silicide light reflecting layer disposed on the protection oxide, wherein the photodiode region receives light from the back surface of the semiconductor layer, where a portion of the received light propagates through the photodiode region to the silicide light reflecting layer, wherein the silicide light reflecting layer is configured to reflect the portion of light received from the photodiode region; a gate oxide disposed on the front surface of the semiconductor layer; and a transfer gate disposed on the gate oxide between the photodiode region and a floating diffusion region formed on the front surface of the semiconductor layer, wherein the silicide light reflecting layer is disposed above the photodiode region, not above the floating diffusion region and is laterally displaced from the transfer gate such that the silicide light reflecting layer is not above the gate oxide of the transfer gate, wherein the protection oxide has a thickness less than a thickness of the transfer gate.