Evaluation of Effective Recombination Velocity Related to the Potential Barrier in n/n+ Silicon Epitaxial Wafers

Abstract

For silicon n/n+ epitaxial wafers (36/0.017 Ωcm), the effective recombination velocity Snn+ related to the potential barrier height at the n/n+ interface has been studied by detecting the leakage currents which are collected at Schottky barrier diodes formed on the substrate. The experimental results obtained are Snn+ =10.6-21.8 cm/s, which increases linearly with increasing photo-generated carrier concentration in the epitaxial layer. These values may be slightly smaller than the real values of effective recombination velocity at the interface, because the recombination effect in the n/n+ transition layer is not taken into account the experimental results. The experimental values are about five times the values expected from a theoretical analysis. These results are discussed in relation to the potential barrier height at the n/n+ junction.