Infrared absorption study on carbon and oxygen behavior in Czochralski silicon crystals

Abstract

The behavior of carbon atoms in relation to oxygen precipitation in Czochralski silicon crystals subjected to various heat treatments is investigated by means of infrared (IR) spectroscopy. It is shown that carbon atoms enhance and modify oxygen precipitation both at 750 and at 1000 °C. Perturbed [Oi−Ci] C(3) centers, which are unstable at a high temperature (1250 °C), have been observed in the specimen subjected to 750 °C heat treatment by IR spectroscopy. The enhancement effect of carbon atoms is explained in two ways: (i) C(3) centers act as effective heterogeneous seeding sites for oxygen precipitation, and (ii) carbon atoms play a catalytic role by modifying interfacial energies or the point defect ambient at the oxygen precipitate surface.