Patent attributes
A wafer laser processing method for forming deteriorated layers in the inside of a wafer having a device area and a peripheral excess area surrounding the device area, the surface of the device area being higher than the surface of the peripheral excess area, involving a first step for forming a deteriorated layer in the insides of the peripheral excess area and device area by applying a laser beam to the peripheral excess area and the device area with its focal point set in the material of the peripheral excess area and the device area from the front surface side of the wafer; and a second step for forming a deteriorated layer in the inside of the device area by applying a laser beam to the device area with its focal point set in the material of the device area without applying the laser beam to the peripheral excess area.
