The localized vibrational modes of C-H complexes, in metal-organic chemical vapor deposited nitride on sapphire, were studied by using a Fourier-transform infra-red spectroscopy technique. Three distinctive localized vibrational modes were observed around 2850, 2922 and 2959/cm in undoped, Si-doped and Mg-doped samples. The peaks were linked to CH, CH2 and CH3 defect complexes, respectively. However, the localized vibrational modes were not observed in some undoped samples, such as high-quality epitaxial layers. It was observed that the frequencies and intensities of the localized vibrational modes were sample-dependent.

Localized Vibrational Modes of Carbon-Hydrogen Complexes in GaN. M.O.Manasreh, J.M.Baranowski, K.Pakula, H.X.Jiang, J.Lin: Applied Physics Letters, 1999, 75[5], 659-61