A Raman study of GaAsN, GaInAsN layers on bevelled samples

Bevelled structures of strained and relaxed GaAsN and GaInAsN layers have been investigated by Raman spectroscopy. The diagnostics of GaAsN and GaInAsN layers was for the first time carried out using this method. The ratio of TO/LO phonon intensities (ITO/ILO) along the bevelled structures was evaluated. This ratio is a measure of the different layer properties and changes in disorder of the atoms in alloys. The layer thickness of the unchangeable disordered alloy was determined to be about 40 nm. The critical layer thickness for relaxation was found to be in the range of 105–140 nm.