Solid state color imager with buried oxide wall fabricated by low pressure selective epitaxy

Using the LPSEI (Low Pressure Selective Epitaxial Isolation) technology, a MOS single chip color imager with buried oxide wall was developed successfully with the use of Selective Oxidation Process (SOP) in order to reduce the blooming and smear effects. The imager has 384 × 485 photodiodes and a monolithic color filter array. Each photodiode was surrounded by buried oxide wall fabricated by the selective epitaxy under low pressure in order to prevent excess electrons from diffusion under field oxide. Thus, the smear current across field oxide was reduced by i0 to 30% compared with the conventional device over the saturation light power.