US Patent 7781253 Image sensor and method of manufacturing the same

An image sensor including a first epitaxial layer formed over a semiconductor substrate; first photodiodes formed spaced apart in the first epitaxial layer; a first isolation region electrically isolating the first photodiodes from each other; a second epitaxial layer formed over the first epitaxial layer; second photodiodes formed spaced apart in the second epitaxial layer; and a second isolation region electrically isolating the second photodiodes from each other.