Patent ID: 8138535

Claim:
A method for manufacturing a pixel sensing circuit, comprising: providing a semiconductor material of a first conductivity type; forming a gate structure configured as an enclosed geometric structure over a portion of the semiconductor material, the gate structure having an interior side and an exterior side; forming a first doped region of a second conductivity type adjacent the interior side of the gate structure; forming a second doped region of the second conductivity type adjacent the exterior side of the gate structure, wherein the gate structure and the first and second doped regions form a transfer transistor and wherein the first doped region serves as a charge storage element; and forming a third doped region of the first conductivity type adjacent the exterior side of the gate structure and laterally surrounding the gate structure, wherein the third doped region, the second doped region, and a portion of the semiconductor material form a photo diode region, and wherein a reset transistor is formed outside the photo diode region.