Semiconductor substrate to be cut with treated and minute cavity region, and method of cutting such substrate

摘要

It is an object to provide a semiconductor (1) to be cut. The laser beam machining method irradiates laser light (L) while positioning a focus point (F) at the inside of a semiconductor (1) to thereby form a treated area (7) based on multiphoton absorption along a planned cutting line of the semiconductor (1) inside the semiconductor (1) and also form a minute cavity (8) at a predetermined position corresponding to the treated area (7) in the semiconductor (1).