Abstract
This invention provides a CMOS image sensor having a pinned photodiode. A P substrate is provided having thereon a P well. The P well is adjacent to a light-sensing region of the CMOS image sensor. A gate electrode of a transfer transistor of the CMOS image sensor is formed on the P well. A self-aligned implantation is performed to form N-type diode diffusion within the light-sensing region. An oblique ion implantation process is then performed to form N-type pocket diffusion directly under the gate electrode. Spacers are formed on sidewalls of the gate electrode. A surface P+ pinning diffusion region is then formed in the diode diffusion region.