Patent attributes
A method of dividing a wafer having a plurality of devices, which are formed in a plurality of areas sectioned by streets formed in a lattice pattern on the front surface and test metal patterns which are formed on the streets, having a metal pattern breaking step for forming a break line in the test metal patterns by applying a pulse laser beam having permeability to the wafer to the rear surface of the wafer with its focal point set near the test metal patterns; a deteriorated layer forming step for forming a deteriorated layer along the streets above the break lines in the inside of the wafer by applying a pulse laser beam having permeability to the wafer to the rear surface of the wafer with its focal point set to a position above the break lines in the inside of the wafer; and a dividing step.
