Patent ID: 7572663

Claim:
A method for manufacturing a CMOS image sensor, comprising: forming a gate electrode on a semiconductor substrate having a gate insulating layer interposed therebetween; forming a photodiode area in a surface of the semiconductor substrate at one side of the gate electrode; forming an LDD area in the surface of the semiconductor substrate at a second side of the gate electrode; forming an interlayer dielectric layer on an entire surface of the semiconductor substrate, and then selectively removing the interlayer dielectric layer such that a portion of the interlayer dielectric layer remains on the photodiode area; performing a first heat treatment after selectively removing the interlayer dielectric layer; sequentially forming a first insulating layer and a second insulating layer on the entire surface of the semiconductor substrate after performing the first heat treatment, wherein an etching selectivity of the first insulating layer is different from an etching selectivity of the second insulating layer; forming a second insulating layer sidewall at sides of the gate electrode by selectively etching the second insulating layer; selectively removing the first insulating layer from a source/drain area of the semiconductor substrate; forming a high-density N type diffusion area in the source/drain area of the semiconductor substrate; performing a second heat treatment process after forming the high-density N type diffusion area; and forming a metal silicide layer on a surface of the high-density N type diffusion area.