Patent attributes
A wafer laser processing method for forming a deteriorated layer along streets in the inside of a wafer having streets formed in a lattice pattern on the front surface, the method comprising: an undulation area deteriorated layer forming step for applying a laser beam along the streets to the undulating area of the wafer without activating the focal point position adjustment means to form a deteriorated layer along the streets in the inside of the undulating area of the wafer; and a stable holding area deteriorated layer forming step for applying a laser beam along the streets to a stable holding area other than the undulating area of the wafer while the focal point position adjustment means is controlled based on a detection signal from the height position detection means to form a deteriorated layer along the streets in the inside of the stable holding area of the wafer.
