Patent ID: 8268662

Claim:
A method of fabricating a complementary metal-oxide-semiconductor image sensor (CIS), comprising: forming an isolation structure in a substrate with a photo-sensitive region and a transistor device region in the substrate, wherein the transistor device region comprises at least a region for forming a transfer transistor later; forming a first dielectric layer and a first conductive layer on the substrate; performing a first ion implantation process to implant a first dopant into the substrate below a position for forming a gate of the transfer transistor and in the photo-sensitive region through the first conductive layer and the first dielectric layer; after performing the first ion implantation process, patterning the first conductive layer and the first dielectric layer to form the gate structure of the transfer transistor on the transistor device region; and forming a photo diode (PD) in the substrate in the photo-sensitive region.