Carbon-Induced Rapid Annihilation of Thermal Double Donors in Czochralski Silicon Studied by Infrared Absorption Spectroscopy

Carbon-rich Czochralski Si shows anomalously rapid annihilation for all the species of thermal double donors at 470-degrees-C in two stages, which have good time correlations with the decrease of substitutional carbon density and also with the formation of two kinds of carbon-related new donors which were previously found. The hypothesis is proposed that Si self-interstitials created during the oxygen aggregation process eject substitutional carbon into an interstitial site, and this interstitial carbon rapidly diffuses to thermal double donors to aggregate with them so as to form electrically inactive clusters which act as the embryos of the carbon-related new donors.