| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide a wafer processing method capable of forming chips with comparatively thick thickness without deteriorating transverse intensity.SOLUTION: The wafer processing method includes: a groove formation step for forming a plurality of grooves 19 with depth less than finish thickness t along division schedule lines from a surface 11a of a wafer 11; a protection tape sticking step for sticking a projection tape 21 to the surface; a laser processing step for forming a modified layer 23 along the division schedule lines in the wafer by locating a condensation point P of a laser beam LB with a wavelength capable of penetrating into the wafer on the rear face side further than the finish thickness in the wafer and applying the laser beam to a rear face 11b along the division schedule lines, and forming a crack layer 25 extending from the modified layer to the grooves along the division schedule lines; and a grinding step for thinning the thickness to the finish thickness by grinding the rear face by grinding means, removing the modified layer and dividing the wafer into chips along the division schedule lines.</p> |
