Patent ID: 8163639

Claim:
A method of fabricating a photo diode, comprising: sequentially forming a buried layer of a first conductivity type, an epitaxial layer of the first conductivity type, and an epitaxial layer of a second conductivity type on a semiconductor substrate; forming a doped oxide film, comprising impurities of the second conductivity type, on the epitaxial layer of the second conductivity type; forming a silicon nitride film on the oxide film; patterning the oxide film and the silicon nitride film to sequentially form an oxide film pattern of the second conductivity type and a silicon nitride film pattern, respectively; and diffusing the second conductivity type impurities from the oxide film pattern into the epitaxial layer of the second conductivity type using a heat diffusion process to form a doped shallow junction layer of the second conductivity type, which converts the oxide film pattern into a non-conductive oxide film pattern.