An active pixel using a photodiode with multiple species of N type dopants
is disclosed. The pixel comprises a photodiode formed in a semiconductor
substrate. The photodiode is an N.sup.- region formed within a P-type
region. The N.sup.- region is formed from an implant of arsenic and an
implant of phosphorus. Further, the pixel includes a transfer transistor
formed between the photodiode and a floating node and selectively
operative to transfer a signal from the photodiode to the floating node.
Finally, the pixel includes an amplification transistor controlled by the
floating node.