Minority carrier lifetime dependence on resistivity in high-purity p-type silicon

This work investigates the dependence of minority carrier lifetime on dopan t concentration and injection level in p-type silicon. For current high-pur ity material grown by the conventional Czochralski technique or applying a magnetic field, iran is no longer the dominant recombination center. An app roach based on Shockley-Rend-Hall theory using published iron-related recom bination centers is shown to be unsuccessful in explaining the experimental ly observed behavior. In this work, the variation of lifetime with doping c oncentration and injection level in high-purity silicon is examined assumin g the presence of a distribution of energy levels in the bandgap. possibly due to some kind of gown-in recombination centers (high-purity silicon reco mbination centers), and it is shown that this approach can indeed explain t he experimental behavior. According to the results, even in the presence of a moderate iron contamination (5E10 cm(-3)) the contribution of high-purit y silicon recombination centers is necessary to fit the experimental data. The comparison between samples grown with and without magnetic field sugges ts that oxygen might he involved in the formation of these recombination ce nters. (C) 1999 The Electrochemical Society. S0013-4651(98)12-088-8. All ri ghts reserved.