CMOS image sensor and method for fabricating the same

A method for fabricating a CMOS image sensor having blue, green and red photodiode regions, comprising:

• forming an epitaxial layer of the first conductivity type in a surface of a semiconductor substrate;
• implanting impurity ions of a second conductivity type in a first predetermined portion of the epitaxial layer to form the blue photodiode region having a first depth, wherein the implanting of the impurity ions in the first predetermined portion comprises patterning a first photoresist layer to expose only the first predetermined portion of the epitaxial layer and using the patterned first photoresist layer as an implantation mask for the blue photodiode region;
• implanting impurity ions of the second conductivity type in a second predetermined portion of the epitaxial layer to form the green photodiode region having a second depth larger than the first depth, wherein the implanting of the impurity ions in the second predetermined portion comprises patterning a second photoresist layer to expose only the second predetermined portion of the epitaxial layer and using the patterned second photoresist layer as an implantation mask for the green photodiode region;
• and
• implanting impurity ions of the second conductivity type in a third predetermined portion of the epitaxial layer to form the red photodiode region having a third depth larger than the second depth, wherein the implanting of the impurity ions in the third predetermined portion comprises patterning a third photoresist layer to expose only the third predetermined portion of the epitaxial layer and using the patterned third photoresist layer as an implantation mask for the red photodiode region.