| 摘要 |
<p>PROBLEM TO BE SOLVED: To prevent detachment of a functional layer, when wafers on which the functional layer is deposited on a surface of a substrate, is divided into chips of individual devices.SOLUTION: In a mask formation step, a mask 50 for covering a region corresponding to a device 13, is formed on a back surface on which a functional layer 12 of a wafer 10 is not formed, in a groove formation step, a groove 16 not reaching to the functional layer 12, is formed on a region corresponding to a street 14 by dry-etching the wafer 10 from the back surface side, and in a partitioning step, the wafer 10 is partitioned along the street 14 by irradiating a bottom 161 of the groove 16 with laser beam 71 along the street 14 from the rear surface side. The device 13 can be prevented from being damaged by detaching the functional layer 12 and one laser processing groove for one street 14 is adequate, thereby the productivity can be improved, thermal strains are not left in the wafer 10, and the decrease in rupture-resistant strength can be prevented.</p> |
