Infrared spectrum of oxygen in silicon

Weak absorption bands appear at 1720, 1227, and 1013 cm−1 in the infrared spectrum of Czochralski silicon. A study of the stress-induced dichroism of these features has been performed to confirm assignment of these bands to combination and overtone modes of interstitial oxygen vibrations. We show that the 1720- and 1227-cm−1 bands involve the antisymmetric stretching mode of vibration which also gives rise to the well-known interstitial oxygen band at 1106 cm−1 (the 9-μm band). Our results are inconclusive for the 1013-cm−1 line.