US Patent 7670864 CMOS image sensor and fabricating method thereof

A CMOS image sensor and method of manufacture reduces the problem of electron loss in a floating diffusion area. A method of fabricating a CMOS image sensor includes forming a gate electrode over a first conductive type semiconductor substrate. A second conductive type first diffusion layer is formed within the semiconductor substrate to be aligned with an edge of one side of the gate electrode. A spacer may be attached to both sidewalls of the gate electrode. A first conductive type second diffusion layer may be formed within the first diffusion layer to leave a distance amounting to a width of the spacer in-between. A second conductive type third diffusion layer may be formed within the semiconductor substrate to be aligned with an edge of the other side of the gate electrode. A first conductive type fourth diffusion layer may be formed over the third diffusion layer, and a first conductive type fifth diffusion layer may be formed under the third diffusion layer.