LASER PROCESSING METHOD

摘要

A modified region is precisely formed at a desired position on the laser irradiation surface of a processing object. Upon trace recording, when an average difference (?) has a value exceeding a predetermined threshold value, a particle zone (Z) is determined, including a line zone (S) where the average difference (?) exceeds the predetermined threshold value. Thus it is determined that particles are present on a line (5) along which cutting is to be carried out and that measuring laser light is reflected diffusely by the particles. In the line zone along which cutting is to carried out, a zone is then detected as the particle zone(Z), in which a control signal is affected by the presence of the particles. The control signal is then corrected in the particle zone (Z), thereby preventing a collective lens from moving more than required because the control signal includes an error due to the effect of the presence of the particles and making the focal point of processing laser light precisely trace the surface (3).