Patent ID: 8026154

Claim:
A laser processing method for irradiating a planar object to be processed with laser light while locating a converging point of the laser light within the object, so as to form a modified region serving as a cutting start point within the object along a cutting line, the method including the steps of: forming a first modified region within the object and generating a first fracture inside of the object from the first modified region extending in a direction substantially parallel to a thickness direction of the object and tilted with respect to a plane extending in the thickness direction and including the cutting line; forming a second modified region within the object and generating a second fracture inside of the object from the second modified region extending in a direction substantially parallel to the thickness direction of the object and tilted with respect to the plane including the cutting line so as to connect the second fracture with the first fracture; and cutting the object along the cutting line from the first and second modified regions by using each of the first and second modified regions as a cutting start region to thereby form an irregular cut section along the first and second fractures as viewed from a side of the object in a direction of the cutting line.