| 摘要 |
PROBLEM TO BE SOLVED: To provide an economically excellent processing method of a wafer, that is used when processing the wafer thin.SOLUTION: A processing method of a wafer (11) having a device region (13) where a plurality of devices (19) are formed and an outer peripheral surplus region (15) surrounding the device region on the surface (11a) side includes a wafer processing step of forming a circular thinned portion (23) by thinning a part of the wafer corresponding to the device region from the back (11b) side, and forming an annular reinforcement portion (25) by keeping the thickness at a part of the wafer corresponding to the outer peripheral surplus region, a protection film coating step of coating only a region on the surface side of the wafer corresponding to the boundary of the thinned portion and reinforcement portion with a protective film (29), a processing groove formation step of forming a processing groove in the wafer by irradiating a region, coated with the protective film, with a laser beam (L) from the surface side of the wafer, and a reinforcement portion removal step for removing the reinforcement portion from the wafer.SELECTED DRAWING: Figure 3 |
