Oxygen-induced recombination centers in as-grown Czochralski silicon crystals

Abstract

Simultaneous quantitative microprofiles of the interstitial oxygen concentration and of the excess carrier lifetime were obtained, for the first time, in Czochralski-grown Si crystals employing double laser absorption scanning. It was found that oxygen concentration maxima and minima along the crystal growth direction coincide with lifetime minima and maxima, respectively. It was further found that the magnitude of oxygen-induced lifetime changes increases dramatically in going from the center to the periphery of the crystal. The present findings imply that ‘‘as-grown’’ oxygen precipitates are involved in lifetime limiting processes.