Patent ID: 7727810
Filing Date: 2010-06-01
Classification: H01L

Abstract:
1. A method of dividing a wafer having a plurality of areas, which are sectioned by streets formed on the front surface in a lattice pattern and a plurality of devices, which are formed in the sectioned areas, along the streets, the method comprising the steps of: a first cutting step for holding the front surface of the wafer directly on a chuck table of a cutting machine and forming a first groove having a depth that is about half of the thickness of the wafer, along the streets from the rear surface of the wafer; a second cutting step performed after the first cutting step for holding the rear surface of the wafer on the chuck table and forming, up to the center portion in the thickness direction of the wafer, a second groove which does not reach the first groove so that an uncut portion is left between the first groove and the second groove, along the streets from the front surface of the wafer; and a dividing step performed after the second cutting step for breaking the uncut portion by exerting external force along the streets of the wafer, on which the first grooves and the second grooves have been formed, wherein the first groove formed in the first cutting step does not reach a peripheral portion of the wafer, and in the second cutting step, the chuck table holding the rear surface of the wafer is an adsorption chuck, and a cutting water supply nozzle for supplying cutting water to a cutting portion on both sides of a cutting blade, so that at the time of cutting, entry of cutting water into the rear surface of the wafer is prevented by an area where the first groove does not reach the peripheral portion of the wafer.