US Patent 7731567 Semiconductor wafer processing method

In a semiconductor wafer processing method of forming a semiconductor wafer having a desired thickness by grinding a rear surface of the semiconductor wafer having a plurality of devices formed on a front surface thereof, the rear surface of the semiconductor wafer is ground so that the semiconductor wafer has a thickness of 10 μm to 100 μm, and a strain layer having a thickness of 0.05 μm to 0.1 μm is left on the rear surface of the semiconductor wafer by the grinding. The strain layer is left to provide the gettering effect, preventing a harmful influence exerted on the quality of the semiconductor devices. Degradation in transverse rupture strength can be prevented by the grinding.