Patent ID: 7645652

Claim:
A method of fabricating a CMOS image sensor, the method comprising: preparing a semiconductor substrate of a first conductivity type having a photodiode region and a transistor region defined therein; forming a first impurity region of the first conductivity type in a portion of the transistor region, wherein the first impurity region has a higher concentration of first conductivity type ions than the semiconductor substrate; forming a gate electrode above the first impurity region with a gate insulating layer interposed therebetween; forming a second impurity region of a second conductivity type at low concentration in the photodiode region; forming a first photoresistive layer on an entire surface of the semiconductor substrate including the gate electrode; patterning the first photoresistive layer to cover the photodiode region and expose source/drain regions of a transistor using an exposure process and a development process; and forming a diffusion region of the second conductivity type by implanting second conductivity type ions into the exposed source/drain regions at a low concentration using the patterned first photoresistive layer as a mask, wherein the first impurity region is formed deeper than the second impurity region, wherein forming the second impurity region comprises: forming a second photoresistive layer on an entire surface of the semiconductor substrate; patterning the second photoresistive layer to expose a portion of the photodiode region using an exposure process and a development process; and implanting second conductive type ions into the exposed portion of the photodiode region at a low concentration using the patterned second photoresistive layer as a mask.