Granted Patent B2

US 7,294,522 · App. 11/318,502 · Granted Nov 13, 2007

Abstract

Claims (13)

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

forming a first conductive type first impurity ion area in an active area of a semiconductor substrate defined by the active area and a field area;

forming a gate electrode on a transistor area of the active area;

forming an insulating film on an entire surface of the semiconductor substrate including the gate electrode;

forming a second conductive type impurity ion area in a photodiode area of the active area;

selectively removing the insulating film on the second conductive type impurity ion area;

growing a silicon epitaxial layer on a surface of the second conductive type impurity ion area; and

forming a first conductive type second impurity ion area in the silicon epitaxial layer.

2. The method of claim 1 , wherein the silicon epitaxial layer is formed on the second conductive type impurity ion area through a selective epitaxial growth process.

3. The method of claim 1 , wherein the step of selectively removing the insulating film further comprises:

leaving the insulating film at sidewalls of the gate electrode so as to isolate the silicon epitaxial layer from the gate electrode through the insulating film.

4. The method of claim 1 , further comprising forming spacers at sidewalls of the gate electrode, and forming a heavily doped second conductive type impurity ion area in the epitaxial layer of the active area at both sides of the gate electrode.

5. The method of claim 4 , wherein the spacers formed at the sidewalls of the gate electrode are adjacent to the silicon epitaxial layer and are formed on the silicon epitaxial layer at the sidewalls of the gate electrode.

Assignments (8)