Complexes consisting of a vacancy and four oxygen atoms, VO4, were found in oxygen-rich Czochralski silicon wafers subjected to rapid thermal annealing (RTA) at 1250C for 30s in Ar/O2 atmosphere by means of Fourier transform infrared spectroscopy with enhanced sensitivity. An absorption band at 985/cm, previously observed only in irradiated Si and assigned to a local vibration mode of VO4, was measured reproducibly in all RTA treated wafers examined. A concentration of about 1.4 x 1013/cm3 of thermally induced VO4 was estimated from the integrated intensity of the band at 985/cm using the known calibration factor for interstitial oxygen.

Interaction of Oxygen with Thermally Induced Vacancies in Czochralski Silicon. V.Akhmetov, G.Kissinger, W.von Ammon: Applied Physics Letters, 2009, 94[9], 092105