Method for fabricating CMOS image sensor

The present invention relates to a method of manufacturing a CMOS image sensor, comprising: forming a gate electrode in the transistor region of a semiconductor substrate having an active region defined by a photodiode region and a transistor region, a gate insulating layer interposed in said transistor region and between the gate electrode; forming a first impurity region of the first conductivity type of the gate electrode side of the transistor region; forming a first and second side walls on both sides of the gate electrode, wherein each side wall having a first side wall insulating layer and a second sidewall insulating layer; forming a second impurity region of the first conductivity type transistor region side of the gate electrode; photoresist layer is coated on the semiconductor substrate, and by exposure and development process for the photoresist layer is patterned to expose the photodiode region; using the patterned photoresist as a mask, forming a second conductivity type in the third impurity region of the photodiode region; using the patterned photoresist layer as a mask selectively to a first sidewall of said photodiode region of a second sidewall insulating layer between the photodiode region and the gate electrode of a predetermined thickness of the insulating layer is removed; by refluxing configuration at a predetermined temperature FIG photoresist layer to cover the gate electrode; using reflowed photoresist layer as a mask to selectively remove the second insulating layer the sidewall of the photodiode region; and using the reflowed photoresist layer as a mask, a gate electrode formed on the first conductivity type fourth impurity region of the third impurity region side.