Abstract: The outer periphery of a workpiece (semiconductor wafer) 42 is caused to come into contact with an abrasive material (abrasive cloth) 28 in a cylindrical polishing drum 23, and the polishing drum 23 and the workpiece 42 are relatively rotated, whereby the region where the outer periphery of the workpiece is in contact with the abrasive cloth 28 is increased and a polishing effect can be increased.

Abstract: A device and method for cutting and grinding a hard but brittle material (such as glass plate, etc.) for producing a doughnut-shaped substrate are provided. The device of the present invention comprises a tubular core rod and shank extending therefrom and coaxial therewith. A plate is attached to the rod and shank and extends therefrom. A skirt is attached to the plate and surrounds the rod. Both the rod and skirt include at least one circumferential cavity. A core drill and a skirt drill are integral with the core rod and skirt, respectively. The cavities, skirt, and drills include diamond whetstone parts.