Raman and X-ray absorption near-edge structure characterization of GaN implanted with O, Ar, Xe, Te and Au

GaN samples implanted with O, Ar, Te, Xe and Au ions, at fluences high enough to cause the formation of an amorphous surface or buried layer, are studied using Raman, X-ray absorption near-edge structure (XANES) and Rutherford backscattering (RBS) spectroscopies. The amorphous character of the as-implanted layers is verified by RBS and confirmed also by the XANES spectra. The Raman spectra of the amorphous surface layers are characterized by broad bands that simulate the phonon density of states, while the contribution of the underlying material is also detected. On the contrary, the spectra of the samples containing a buried amorphous layer are more structured due to the contribution of light scattered from the partially damaged layer which exists in between the surface and the buried amorphous layer.