Local Vibrational Modes of Carbon-Hydrogen Complexes in Proton Irradiated AlGaN

Abstract

Local vibrational modes (LVMs) of carbon-hydrogen (C-H) complexes in proton implanted AlGaN grown on sapphire by metalorganic chemical vapor deposition (MOCVD) were investigated using Fourier transform infrared (FTIR) spectroscopy. The LVMs exhibit five distinctive peaks in the spectral region of 2846-2963 cm-', which are due to the symmetric and asymmetric stretching modes of C-H. (n=1-3). The LVMs intensities in doped A1GaN are increased as irradiation dose is increased in the entire irradiation dose range used without reaching the saturation stage. On the other hand, undoped samples show that LVMs intensity increase then either decreased or saturated as the irradiation dose is increased above 5x10 16 cm. Proton irradiation causes a drastic increase in the CH 3 LVM while electron irradiation causes the opposite effect suggesting strongly that the observed LVMs are truly due to CH complexes.