Single crystal wafers and a method of preparation thereof

摘要

Improved commercial single crystal wafers (250), as shipped to end users form a full circle, and comprise a "stress concentration notch" (172) which accurately defines a desired cleavage plane. The stress concentration notch is introduced into the wafers in bulk by means of a properly oriented cut along the length of a single crystal ingot, after machining the ingot to the desired end product diameter, and prior to sawing the ingot into slices. The stress concentration notch uniquely defines the first and second faces of the wafer.