Patent ID: 8133751

Claim:
A method of forming a CMOS image sensor device, the method comprising: providing a semiconductor substrate having a P-type impurity characteristic, the semiconductor substrate includes a surface region; forming a gate oxide layer overlying the surface region; forming a first gate structure overlying a first portion of the gate oxide layer, the first gate structure has a top surface region and at least a side region; forming an N-type impurity region in a portion of the semiconductor substrate to form a photodiode device region from at least the N-type impurity region and the P-type impurity; forming a blanket spacer layer including an oxide on nitride on oxide (ONO) structure overlying at least the first gate structure, the ONO structure having a nitride layer sandwiched between a top oxide layer and a bottom oxide layer; and removing the top oxide layer, the nitride layer, and a portion of the bottom oxide layer of the ONO structure to form one or more spacer structures for the first gate structure, wherein a remaining bottom oxide layer covers the entire photodiode device region.