Recombination at the interface between silicon and stoichiometric plasma silicon nitride

The injection level dependence of the effective surface recombination velocity (S-eff) for the interface between crystalline silicon and stoichiometric silicon nitride. prepared by high-frequency direct plasma enhanced chemical vapour deposition (PECVD), has been comprehensively studied. A wide variety of substrate resistivities for both n-type and p-type dopants have been investigated for minority carrier injection levels (Deltan) between 10(12) and 10(17) cm(-3). Effective lifetimes of 10 ms have been measured for high resistivity n-type and p-type silicon, the highest ever measured for silicon nitride passivated wafers, resulting in S-eff values of 1 cm s(-1) being unambiguously determined. The S-eff (Deltan) dependence is shown to be constant for n-type silicon under low injection conditions, while for p-type silicon, there is a clear minimum to Seff for injection levels close to the doping density. Further, the S-eff (Deltan) dependence for these stoichiometric silicon nitride films appears to be weaker than that for other high-quality, silicon-rich silicon nitride films prepared by remote PECVD.