Vibrational Spectra of Nitrogen-Oxygen Defects in Nitrogen Doped Silicon using Density Functional Theory

ABSTRACTThe vibrational spectra of N-pairs and nitrogen-vacancy-oxygen defects in nitrogen doped Czochralski silicon have been investigated using density functional theory calculations. We found that 771 cm−1 and 967 cm−1 lines measured by FTIR are fingerprints for N-pairs in interstitial position. These confirm that nitrogen atoms are paired and bonded to Si atoms. Calculated local vibration modes of N2On complexes provide the best matching with observed FTIR frequency of N-O complexes. Nonetheless, VmN2On (m,n =1,2) can develop during crystal cooling or wafer processing, as revealed by local vibrational modes falling around, 806 and 815 cm−1 FTIR frequencies.