Method for machining workpieces of brittle hard material into wafers

Abstract

A method for machining a disk-shaped workpiece, for example having a thickness of between 350 and 1200 microns, formed of brittle crystalline material having a Vickers hardness greater than about 7,000 N/mm.sup.2 in the manufacture of a wafer having a fine thickness, such as in the range of between about 60 and 250 microns, comprises a "cross" grinding operation including the steps of situating the workpiece in opposed relationship to a flat grinding surface of a rotating cup-type grinding wheel and infeeding or plunging the grinding wheel with respect to the workpiece in a direction substantially parallel to the axis of rotation of the grinding wheel at a controlled rate while maintaining the workpiece fixed and stationary with respect to the axis of rotation of the grinding wheel until a layer of the workpiece having a specifically predetermined optimal thickness has been abraded. The method of the invention provides increased yields of wafers with improved surface quality and precision and with decreased depth of damage of the crystal lattice structure.

Dependencies are inferred from the claim text.