Patent ID: 8309436

Claim:
A method of producing an epitaxial substrate for a solid-state imaging device, comprising: forming a gettering sink by injecting a laser beam to a semiconductor substrate through one surface thereof, condensing the laser beam to an arbitrarily selected portion of the semiconductor substrate, thereby causing a multi-photon absorption process to occur in the portion, and forming a gettering sink having a modified crystal structure; and epitaxially growing at least two epitaxial layers on the semiconductor substrate in which the gettering sink is formed, wherein the laser beam is an ultra-short pulse laser beam having a pulse width in a range of 1.0×10 −15 to 1.0×10 −8 seconds and a wavelength in a range of 300 to 1200 nm, the semiconductor substrate is made of a single crystalline silicon, and the gettering sink includes silicon of an amorphous structure, and wherein the ultra-short pulse laser beam is controlled to have a peak power density of 1.0×10 6 to 1.0×10 11 second·W/cm 2 and a beam diameter of 1 μm to 10 mm in the portion of the semiconductor substrate.