US Patent 7718511 Processing method for wafer

A processing method for a wafer includes: preparing a wafer which has a device region having plural devices formed on a surface of the wafer; and a peripheral reinforcing portion which is integrally formed around the device region and has a projection projecting outwardly on a rear surface of the wafer. The processing method further includes: holding the wafer on a holding surface of a rotatable holding table such that the rear surface of the wafer is exposed and the surface of the wafer closely contacts the holding table. The processing method further includes: thinning the peripheral reinforcing portion by cutting and removing at least the projection of the peripheral reinforcing portion of the wafer by using a cutting tool having a rotational shaft parallel to the holding surface, while rotating the wafer by rotating the holding table after the holding of the wafer. The peripheral reinforcing portion is thinned so as to have a thickness equal to or thinner than that of the device region by the thinning.