| 摘要 |
PROBLEM TO BE SOLVED: To inhibit damages of metal wiring without deteriorating cutting performance.SOLUTION: A laser processing method comprises a step of forming modified regions 7 inside a workpiece 1 along scheduled cutting lines 5 by radiating laser beams L to the workpiece 1 having a semiconductor substrate 2 and a lamination part 4 including metal wiring 4b from a rear face 21 opposite to a surface 3 on the lamination part 4 side. The step of forming the modified regions 7 includes a first modified region formation step of forming first modified regions 7a in the workpiece 1 at positions on the surface 3 side by radiating laser beams L, and a second modified region formation step of forming second modified regions 7b in the workpiece 1 at positions on the rear face 21 side than the first modified regions 7a by radiating laser beams L. A pulse width of the laser beams L irradiated when the first modified regions 7a are formed is smaller than a pulse width of the laser beams L irradiated when the second modified regions 7b are formed. |
