Method of processing an object with formation of three modified regions as starting point for cutting the object

摘要

A laser beam process method and of cutting an object (1) without producing a fusing and a cracking out of a predetermined cutting line on the surface of the object (1), wherein a pulse laser beam (L) is radiated on the predetermined cut line (5) on the surface (3) of the object (1) under the conditions causing a multiple photon absorption and with a condensed point (P) aligned to the inside of the object (1), and a modified area (9) is formed inside the object (1) along the predetermined determined cut line (5) by moving the condensed point along the predetermined cut line (5), whereby the object (1) can be cut with a rather small force by cracking the object (1) along the predetermined cut line (5) starting from the modified area and, because the pulse laser beam (L) radiated is not almost absorbed onto the surface (3) of the object (1), the surface (3) is not fused even if the modified area is formed.