Method of cutting a substrate with forming along a line of overlapping modified spot inside the substrate

摘要

A method of cutting a substrate without producing a fusing and a cracking out of a predetermined cutting line on the surface of the substrate, wherein a pulse laser beam is radiated on the predetermined cut line (5) on the surface of the substrate under the conditions causing a multiple photon absorption and with a condensed point aligned to the inside of the substrate, and a modified spot (90) is formed inside the substrate along the predetermined determined cut line (5) by moving the condensed point along the predetermined cut line (5), whereby each modified spot (90) overlaps at least one of the other modified spots (90).