Raman scattering study of BxGa1-xN growth on AIN template substrate

In this study, Raman scattering measuremenst are reported on the BxGa1-xN layers grown on AIN on sapphire templates by MOVPF. The boron content covered the composition range from 0% (pure GaN) to 1-75%. The Raman spectra were recorded at 300 K with a confocal micro Raman spectrometer in the backscattering geometries. Raman cartography at a lateral resolution of 1 mu m was performed to study the spatial variation of the phonon peaks characteristics. The homogeneity of BGaN layers was studied una the phonon modes characteristics are determined as a function of composition with respect to the laser polarisation. The I-2 and A(1)(LQ) modes frequencies are shifted with respect to the pure GaN. The A(1)(LO) mode behaviour correlates well with the free carriers concentration measured by Hall Effect method indicating a phonon-plaasmon coupling decreasing with increasing boron content in alloy. (C) 2008 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.