| 摘要 |
PROBLEM TO BE SOLVED: To provide a laser processing method in which a reformed layer is formed in a wafer by emitting a laser beam from the back side of the wafer without using an annular frame.SOLUTION: A laser processing method comprises: an adhering step in which the back side 11b of a wafer is attached to an adhesive tape 12 having the same size as the wafer 11 or a larger size; a holding step in which the adhesive tape with the wafer attached thereto is brought into close contact with the holding surface of a plate 14, which is transparent with respect to a laser beam emitted to the wafer, via a liquid and the wafer is thereby held by the plate via the adhesive tape; and a reformed layer formation step in which after the holding step, while a light condensing point P is located in the wafer held by the plate from the back side of the holding surface of the plate, a laser beam of transmissive wavelength is emitted to the wafer from the back side of the wafer via the plate along a predetermined division line, thereby forming a reformed layer 19 in the wafer. |
