Patent ID: 8338271

Claim:
A method for manufacturing a chip including a functional device by irradiating a planar object to be processed, wherein the object comprises a first lateral surface and an opposing lateral surface opposed to the first lateral surface, with laser light while locating a converging point within the object, so as to form a modified region acting as a cutting start point within the object along a cutting line in the object, the method comprising the steps of: irradiating the laser light so that the laser light is incident from the first lateral surface, thereby forming first and second modified regions, arranged in a row in a thickness direction of the object, along the cutting line; irradiating the laser light from the first lateral surface to pass through either the first or second modified regions after the procedure of forming the first and second modified regions, thereby forming a third modified region, positioned between the first and second modified regions, along the cutting line; and cutting the object along the cutting line from the modified region acting as a cutting start point.