Low defect density silicon and a process for producing low defect density silicon wherein V/G0 is controlled by controlling heat transfer at the melt/solid interface

摘要

The present invention relates to single crystal silicon, in ingot or wafer form, which contains an axially symmetric region which is free of agglomerated intrinsic point defects, and a process for the preparation thereof. The process including controlling growth conditions, such as growth velocity, v, instantaneous axial temperature gradient, G0, and the cooling rate, within a range of temperatures at which silicon self-interstitials are mobile, in order to prevent the formation of these agglomerated defects. The control of G0 is accomplished by controlling heat transfer at the melt/solid interface.