Using re-association kinetics to identify impurities in p-type silicon

摘要

A new approach to in-line monitoring of impurities that pair With boron in p-type silicon is based on recombination lifetime measurements performed by a commercially available surface-charge profiler tool. The method monitors the re-association kinetics of metastable complexes that are formed between boron and individual atoms of impurities - such as iron and hydrogen - in the device region, near the surface of silicon wafers. This article describes the concept and proposes in-process control applications based on minority carrier recombination-lifetime degradation characteristics of impurities during the re-association process.