| 摘要 |
The purpose of the present invention is to provide a wafer processing method which can inhibit damage to a device on the surface of a wafer by a transmitted light when a modification layer is formed within the wafer by irradiating pulse laser beams wherein a wave has transmissivity against a silicon wafer. The present invention is a wafer processing method which processes a silicon-made wafer where a plurality of devices are divided by a plurality of lines for division. The method comprises: a modification layer forming step of irradiating pulse laser beams an area corresponding to the lines for division from the back of the wafer by locating a light concentrating point of the pulse laser beams wherein a wave has transmissivity against the wafer within the wafer, and relatively processing and transferring a holding means and a laser beam irradiating means, thereby forming a modification layer within the wafer; and a dividing step of applying, after conducting the modification layer forming step, an external force to the wafer to divide the wafer along the lines for division starting from the modification layer as a division point. In the modification layer forming step, the light concentrating point of the pulse laser beams is located within the wafer by omitting some pulse laser beams on an area from the center of the pulse laser beams irradiating the wafer to the outer circumference of a lower side in the processing/transferring direction. |
