Semiconductor substrate cutting method

摘要

A method for cutting a semiconductor substrate having a front face formed with functional devices together with a die bonding resin layer. A wafer having a front face formed with functional devices is irradiated with laser light while positioning a light-converging point within the wafer with the rear face of the wafer acting as a laser light incident face, so as to form a starting point region for cutting due to a modified region within the wafer along a cutting line. When an expansion film is attached to the rear face by way of a die bonding resin layer after forming the starting point region and then expanded, a fracture can be generated from the starting point region which reaches the front face and rear face, consequently, the wafer and die bonding resin layer can be cut along the cutting line.