US Patent 7902618 Backside illuminated imaging sensor with improved angular response

A backside illuminated imaging pixel with improved angular response includes a semiconductor layer having a front and a back surface. The imaging pixel also includes a photodiode region formed in the semiconductor layer. The photodiode region includes a first and a second n-region. The first n-region has a centerline projecting between the front and back surfaces of the semiconductor layer. The second n-region is disposed between the first n-region and the back surface of the semiconductor layer such that the second n-region is offset from the centerline of the first n-region.