Semiconductor wafer thermal gradient zone melting processing - using a wafer with a bevelled edge to minimise thermal gradient edge distortions

摘要

In processing a semiconductor wafer by thermal gradient zone melting (TGZM) to form doped regions of recrystallised material in the wafer, a wafer is used whose outer edge is bevelled at predetermined included angle (alpha) with the bottom surface of the wafer. Pref. alpha = 41 degrees plus-or-minus 3 degrees. The bevelled edge minimises thermal gradient edge distortions without the need for additional processing steps or heat shields or guard rings, etc.