(Invited) The Impact of Oxide Precipitates on Minority Carrier Lifetime in Czochralski Silicon

Abstract

Oxide precipitates form in silicon for microelectronic and photovoltaic applications, and act as strong recombination centres. We have measured the injection-dependence of minority carrier lifetime in ~50 samples from p-type and n-type Czochralski silicon wafers with a wide range of precipitate densities. We find that all the data can be parameterized in terms of two independent Shockley-Read-Hall centres. The first is at EV + 0.22eV, and has a capture coefficient for electrons 157 greater than that for holes. The second is at EC - 0.08eV and has a capture coefficient for holes ~1,200 greater than that for electrons. The density of the centres is approximately dependent on the precipitate concentration. The existence of dislocations and stacking faults around the precipitates increases the density of both centres.