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

摘要

The 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 N_2O_n complexes provide the best matching with observed FTIR frequency of N-O complexes. Nonetheless, V_mN_2O_n (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.