Nature of oxygen donor in Czochralski-grown silicon

Changes in the substitutional carbon and interstitial oxygen concentrations due to the formation of oxygen donors were studied on carbon-rich Czochralski-grown silicon (7-9×1017 carbon atoms/cm3). The result suggests that the new donor formation is controlled not by the substitutional carbon concentration directly, but by a density of some unknown embryo. A donor formation was observed in a 450°C annealing which was preceded by a 650°C annealing without new donor formation. This donor does not exhibit a 0.767 eV line in a measurement of the photoluminescence spectrum. However,it exhibits an infrared absorption band which is characteristic to the thermal donor.