Carbon-related radiation damage centres in Czochralski silicon

Abstract

The authors show that the intensity of the 790 meV electronic absorption line and the C(3) vibrational line at 865 cm-1 correlate in Czochralski (CZ) silicon regardless of carbon concentrations, radiation doses and stages of annealing. Three weak vibrational lines at 529, 550 and 742 cm-1 are shown to correlate with the C(3) lines. Symmetry arguments, estimates of the concentrations of the centres and the local mode energies are consistent with all these transitions occurring at the same radiation-induced complex. A simple model of the radiation damage process in which mobile carbon interstitial atoms are trapped predominantly at carbon substitutional atoms or oxygen atoms is shown to be quantitatively consistent with these and earlier data. The strength of the C(3)/790 meV lines correlates with the carbon content in CZ silicon, providing a possible new means of measuring carbon in silicon.