Abstract: A wafer processing method includes a modified layer forming step of applying a laser beam of a wavelength having transmitting property to a wafer with a focusing point of the laser beam positioned inside the wafer at positions corresponding to division lines, thereby to form modified layers, and a back side grinding step of holding the wafer on a chuck table of a grinding apparatus, grinding a back side of the wafer to thin the wafer, and dividing the wafer into individual device chips from cracks that are generated from the modified layers formed inside the wafer along the division lines to the division lines formed on a front side of the wafer. In the modified layer forming step, in a case where triangular chips each having a surface area smaller than the device chips are to be formed, the application of the laser beam is stopped in a region where the triangular chips are to be formed.

Abstract: A wafer processing method includes a modified layer forming step of applying a laser beam of a wavelength having transmitting property to a wafer with a focusing point of the laser beam positioned inside the wafer at positions corresponding to division lines, thereby to form modified layers, and a back side grinding step of holding the wafer on a chuck table of a grinding apparatus, grinding a back side of the wafer to thin the wafer, and dividing the wafer into individual device chips from cracks that are generated from the modified layers formed inside the wafer along the division lines to the division lines formed on a front side of the wafer. In the modified layer forming step, in a case where triangular chips each having a surface area smaller than the device chips are to be formed, the application of the laser beam is stopped in a region where the triangular chips are to be formed.