Patent ID: 8003424

Claim:
A method for fabricating an image sensor, the method comprising: forming a channel region of a transfer transistor; forming a pocket photodiode under a first portion of said channel region by performing a first implantation with a tilt angle to result in a tilted dopant profile of the pocket photodiode; forming a photosensitive device in a photo diode region of a semiconductor substrate of a first conductivity type, wherein the photosensitive device includes a main photodiode of a second conductivity type formed with a second implantation that is after and separate from said first implantation; wherein the pocket photodiode is of the second conductivity type, and wherein the pocket photodiode and the semiconductor substrate into which the pocket photodiode is implanted are of opposite conductivity types; forming a floating diffusion region of the second conductivity type with the channel region being disposed between the photosensitive device and the floating diffusion region; and forming a gate dielectric and a transfer gate disposed above the channel region for the transfer transistor; wherein the first implantation with the tilt angle for forming the pocket photodiode is performed before formation of the transfer gate.