Patent ID: 7544588
Filing Date: 2009-06-09
Classification: B23K

Abstract:
1. A laser processing method for a wafer, the wafer having a plurality of regions defined by streets formed in a lattice pattern on a face of the wafer, the defined regions having a plurality of devices formed therein, the method being arranged to irradiate the wafer with a laser beam along the streets, thereby forming laser processed grooves along the streets, comprising: a processed groove formation step of irradiating the wafer with the laser beam, which has a wavelength absorbable to the wafer, along the streets, with a focus spot being positioned on a laser beam irradiation surface of the wafer, thereby forming the laser processed grooves along the streets; and a processed groove finishing step of irradiating the wafer with the laser beam, which has a wavelength absorbable to the wafer, along the laser processed grooves, with a focus spot being positioned beyond a bottom of the laser processed grooves formed by the processed groove formation step, thereby finishing both sides of the laser processed grooves.