| 摘要 |
PROBLEM TO BE SOLVED: To provide a wafer processing method capable of suppressing damage to a device on a surface of a wafer due to refraction or reflection of a laser beam on a crack.SOLUTION: A wafer processing method for processing a wafer composed of a silicon formed by partitioning a plurality of devices into a surface of the wafer by a plurality of division schedule lines comprises the steps of: forming a modified layer inside the wafer by irradiating the region corresponding to the division schedule lines from a rear surface 11b of the wafer with a modified pulse laser beam LB2 in which energy is concentrated in the outer peripheral part of the laser beam except the central part when forming the modified layer inside the wafer by irradiating the wafer with the pulse laser beam of a wavelength having permeability to the silicon (modified layer forming step); and applying external force to the wafer and dividing the wafer along the division schedule lines using the modified layer as a division start point after performing the modified layer forming step(dividing step).SELECTED DRAWING: Figure 5 |
