摘要 |
<p>The center shift of outer periphery edge (105) of a wafer (100) mounted on a chuck table (36) is detected with coordinate of center of the wafer and coordinate of rotation center of the chuck table. The chuck table and the wafer are moved relatively corresponding to the shift of outer periphery edge of the wafer so that center of the wafer and center of the chuck table are aligned. A separation groove (107) is formed along the boundary line (106) of device region (104) the wafer by irradiating a laser beam to the boundary of the wafer while rotating the chuck table.</p> |