Patent ID: 8557624

Claim:
A method for fabricating a pixel sensor cell, the method comprising: forming a first gate dielectric with a thick region and a thin region on a top surface of a semiconductor layer; when forming the first gate dielectric, forming a second gate dielectric including a first layer and a second layer on the top surface of the semiconductor layer; concurrently forming a first gate electrode on the first gate dielectric and a second gate electrode on the second gate dielectric to respectively define a transfer gate structure and a reset gate structure; and forming a floating diffusion region in the semiconductor layer laterally located between the transfer gate structure and the reset gate structure, wherein the thick region of the first gate dielectric is laterally positioned between the photosensing element and the thin region of the gate dielectric, the thin and thick regions of the first gate dielectric and the first layer of the second gate dielectric include respective portions of a silicon dioxide layer, and the second layer of the second gate dielectric and the thick region of the first gate dielectric include respective portions of a high-k dielectric layer disposed on the portions of the silicon dioxide layer.