| 摘要 |
PROBLEM TO BE SOLVED: To provide a wafer division method to certainly cut a wafer with a metal layer on a back face thereof into each device chip.SOLUTION: A division method for a wafer 11 including a metal layer 21 formed on a back face thereof comprises the steps of: preparing the wafer 11 having a device region and an outer circumference excessive region on a surface thereof, in which a metal layer 21 is formed only on a back side corresponding to the device region; removing the metal layer 21 in a region of the wafer 11 corresponding to a predetermined division line 17a; positioning a light focal point for a laser beam 27 in the wafer 11, and irradiating the region from which the metal layer 21 is removed along the predetermined division line 17 with the laser beam 27 to form a modified layer; and cutting the wafer 11 out into each chip by applying external force thereto. In a back side region of the wafer 11 corresponding to an outer circumference excessive region where the metal layer 21 is not formed, the modified layer is formed more than the device region. |
