Patent ID: 7420603

Claim:
A solid-state image pickup device comprising: a plurality of pixels, each of said pixels comprised of: a substrate well region of a second conductivity type formed in a substrate; a photoelectric-converting portion formed in the substrate well region for photoelectrically converting incident light into signal charges and accumulating said signal charges; an accumulation region for converting said accumulated signal electric charges into a voltage formed by implanting ions of a first conductivity type into the substrate well region, said first conductivity type being opposite said second conductivity type; and a transfer gate for transferring said signal charges accumulated in said photoelectric-converting portion to said accumulation region, said transfer gate defining a channel region existing in the substrate below the transfer gate between said photoelectric converting portion and said accumulation region, wherein two transfer gate well regions are formed in the channel region under said transfer gate including a first transfer gate well region formed by implanting ions of the first conductivity type in only a portion of the channel region located laterally adjacent the accumulation region, and a second transfer gate well region formed by implanting ions of the second conductivity type in only a portion of the channel region located laterally adjacent the photo-electric converting portion such that the concentration of ions of the second conductivity type in the second transfer gate well region is higher than the concentration of ions of the second conductivity type in the substrate well region, said second transfer gate well region extending from an end of the channel region closest to the photoelectric-converting portion and at least partially across the channel region towards the first transfer gate well region.