Method for fabricating CMOS image sensor

1 . A method for fabricating a CMOS image sensor comprising:

forming a metal pad on a pad region of a semiconductor substrate having an active region and the pad region;

forming an insulating film on a surface of the semiconductor substrate, including the metal pad;

forming an opening to expose the metal pad by etching a portion of the insulating film corresponding to the metal pad;

forming a pad passivation film on the insulating film, including the opening;

forming color filter layers on a portion of the pad passivation film corresponding to the active region;

removing a portion of the pad passivation film corresponding to the pad region; and

forming microlenses over the color filter layers after removing the portion of the pad passivation film corresponding to the pad region.

2 . The method as claimed in claim 1 , further comprising forming a planarization layer between the color filter layers and the microlenses.

3 . The method as claimed in claim 2 , wherein the pad passivation film is removed using the planarization layer as a mask.

4 . The method as claimed in claim 1 , wherein the pad passivation film is formed at a thickness of about 800 Å to about 1200 Å.

5 . The method as claimed in claim 1 , wherein the step of forming the insulating film includes forming an oxide film on the entire surface of the semiconductor substrate, including the metal pad, and forming a nitride film on the oxide film.

6 . The method as claimed in claim 1 , further comprising performing a thermal curing process after forming the pad passivation film.

7 . The method as claimed in claim 1 , wherein the pad passivation film is removed by a plasma dry etching process.

8 . The method as claimed in claim 1 , wherein the pad passivation film includes a PE TEOS film.

9 . The method as claimed in claim 5 , wherein the oxide film includes a USG HDP film.

10 . The method as claimed in claim 5 , wherein the nitride film includes a PECVD SiN film.