Abstract: A process for polishing silicon wafers includes the step of carrying out last polishing step in the polishing operation in such a way that a protective film of silicon dioxide is produced on the surface of the polished wafer. The film does not interfere with e.g., the subsequent oxidation processes. The protective film protects the wafer surface from the many effects arising in subsequent processes which may unfavorably influence the quality of the surface.

Abstract: A grinding machine in which a workpiece, to have grinding operations carried out at different locations along the workpiece at different radii and at different angles, is mounted between centers on a slideway to present the locations on the workpiece to a motor driven grinding wheel mounted in a grinding head. The grinding head is mounted on a slideway to traverse the grinding wheel towards and away from the periphery of the workpiece. The grinding wheel is mounted on the slide for rotational adjustment about an axis extending tangential to the periphery of the grinding wheel at a location where the grinding wheel acts on the workpiece for adjustment of the angle of cut of the grinding wheel. Since the grinding wheel turns about an axis when its angle is adjusted, the position of an angle of cut is not otherwise varied by the angular adjustment of the grinding wheel.