| 摘要 |
PROBLEM TO BE SOLVED: To provide a modified layer forming method that prevents ablation even when a focal point of a pulsed laser beam is located on a surface of a workpiece.SOLUTION: In a modified layer forming method, a pulsed laser beam having a transmission wavelength to a workpiece is emitted from a predetermined irradiation surface in the condition where a focal point of the pulsed laser beam is set inside the workpiece, thereby forming a desired modified layer inside the workpiece. The output of the pulsed laser beam is reduced to an output that cannot process the workpiece when a surface adjacent to the irradiation surface of the workpiece is located at the irradiation position of the pulsed laser beam. |
