Patent ID: 7436011

Claim:
A CMOS image sensor, comprising: a semiconductor substrate of a first conductivity type; a pinned photodiode formed in a light-sensing region of said semiconductor substrate, said pinned photodiode comprising a charge-accumulating diffusion region of a second conductivity type and a surface pinning diffusion region of said first conductivity type overlying said charge-accumulating diffusion region; and a transfer transistor adjacent to said pinned photodiode, wherein the transfer transistor has a transfer gate having at least two different gate lengths, and said transfer gate comprises a first gate segment and a second gate segment overlapping with said charge-accumulating diffusion region, wherein said first gate segment is longer than said second gate segment by a predetermined offset in a gate lengthwise direction; and wherein a first overlapping portion between said first gate segment and said charge-accumulating diffusion region is greater than a second overlapping portion between said second gate segment and said charge-accumulating diffusion region.