Laser lift off systems and methods that overlap irradiation zones to provide multiple pulses of laser irradiation per location at an interface between layers to be separated

摘要

Laser lift off systems and methods overlap irradiation zones to provide multiple pulses of laser irradiation per location at the interface between layers of material to be separated. To overlap irradiation zones, the laser lift off systems and methods provide stepwise relative movement between a pulsed laser beam and a workpiece. The laser irradiation may be provided by a non-homogeneous laser beam with a smooth spatial distribution of energy across the beam profile. The pulses of laser irradiation from the non-homogenous beam may irradiate the overlapping irradiation zones such that each of the locations at the interface is exposed to different portions of the non-homogeneous beam for each of the multiple pulses of the laser irradiation, thereby resulting in self-homogenization. Thus, the number of the multiple pulses of laser irradiation per location is generally sufficient to provide the self-homogenization and to separate the layers of material.