Recombination lifetime in oxygen-precipitated silicon

The recombination lifetime degrades when interstitial oxygen precipitates in Czochralski-grown silicon. We have observed a more severe degradation in p-type than in n-type material. Based on recombination lifetime, deep-level transient spectroscopy, Fourier-transform infra-red transmission, and transmission electron microscopy measurements, we attribute the degradation mainly to interface states at the precipitate-silicon interface acting as recombination centers. Positive charge in the oxygen precipitates (OP's), causing an electron-attractive space-charge region (scr) around the precipitate in p-Si and a hole-repulsive accumulation layer in n-Si, is proposed to explain the lifetime differences between n-type and p-type silicon.