Reduced Recombination Activity of Nickel Precipitates: Another Advantage of n-type Silicon

摘要

The impact of Ni surface contamination on the effective carrier lifetime has been studied for a range of Ni concentrations for n- and p-type wafers of different resistivities, after high temperature processing. Measurements performed before and after surface etching clearly show that the dominant Ni-related recombination centers are precipitates at the wafer surfaces. These Ni precipitates were found to be significantly more active in terms of recombination in p-type silicon than in n-type material. The effective lifetimes have been used to calculate the corresponding surface recombination velocities, which is a more appropriate metric for the impact of surface precipitates on recombination. This reveals that the recombination activity of the Ni precipitates increases approximately linearly with the initial Ni dose.