Patent ID: 8044444

Claim:
An image sensor, comprising: a transfer gate formed on a surface of a semiconductor substrate; a first n-type ion implantation region for a photodiode formed in the semiconductor substrate, aligned with one side of the transfer gate, and having a first width and a first ion implantation depth; a second n-type ion implantation region aligned at the one side of the transfer gate, wherein the second n-type ion implantation region is configured to enclose the first n-type ion implantation region, to have a second width that is wider than the first width, and to have a second ion implantation depth that is deeper than the first ion implantation depth; a p-type ion implantation region aligned at the one side of the transfer gate, wherein the p-type ion implantation region is configured to extend along the surface of the semiconductor substrate from the one side of the transfer gate, through the first n-type ion implantation region, and into the second n-type ion implantation region; spacers formed on sidewalls of the transfer gate; and a floating diffusion region formed at another side of the transfer gate.