Si substrate structure for solid-state color imagers

Si substrate structure for a low-noise MOS-type color imager was proposed. Photodiodes fabricated in a p-well suppress noise due to spurious red and infrared sensitivity, blooming, and smear, Furthermore, defects are diminished by optimized three-step intrinsic gettering and a new plural ion implantation method. Defects include those due to the defect nuclei inherent in a Si substrate grown by the Czochralski method and those due to high-dose boron-ion implantation for a low-resistance well layer.