Carrier lifetime studies of strongly compensated P-type czochralski silicon

Carrier lifetimes have been measured in compensated p-type single-crystal silicon wafers. Trace amounts of interstitial iron were found to provide a convenient method for measuring the total concentrations of acceptors and donors in this material, based on measuring the re-pairing rate of iron-acceptor pairs, coupled with resistivity measurements and a suitable mobility model. The results were found to be in good agreement with dopant concentrations measured independently by glow-discharge mass spectrometry. In addition, there appears to be a reduction in the bulk lifetime in compensated wafers when compared to non-compensated wafers of similar net doping. Possible mechanisms behind this reduction are discussed.