CMOS image sensor and method for manufacturing the same

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

forming a plurality of transistors on a semiconductor substrate;

forming a metal line over the plurality of transistors for electrically connecting the plurality of transistors;

forming a plurality of photodiodes over the metal line;

forming a color filter on the plurality of photodiodes;

forming a planarization layer on the color filter; and

forming a micro-lens on the planarization layer.

2. The method of claim 1 , further comprising:

forming a metal dielectric layer over at least one of the plurality of transistors before forming the plurality of photodiodes.

3. The method of claim 2 , wherein forming the plurality of photodiodes comprises:

forming a through-hole through the metal dielectric layer to a gate electrode of the at least one of the plurality of transistors;

forming a plug by filling the through-hole with a conductive material;

depositing a silicon layer on the metal dielectric layer;

forming a photoresist pattern for exposing a portion that corresponds to the plug on the silicon layer; and

implanting P-type and N-type impurity ions into the silicon layer using the photoresist pattern as a mask.

4. The method of claim 3 , further comprising:

forming an isolation region between each of the plurality of photodiodes.

5. The method of claim 1 , further comprising:

forming a first metal dielectric layer between the plurality of transistors and the metal line; and

forming a second metal dielectric layer between the metal line and the plurality of photodiodes.