Correlation between Raman intensity of the N-related local vibrational mode and N content in GaAsN strained layers grown by MOVPE

GaAs1−xNx alloy films (0⩽x⩽0.055) grown on GaAs (0 0 1) substrates by metalorganic vapor phase epitaxy (MOVPE) using TBAs and DMHy as As and N precursors, respectively, have been investigated by Raman spectroscopy. It was found that, with incorporating N up to x=0.055x=0.055, a single N-related localized vibrational mode (LVM) is observed at around 468–475 cm−1. We have investigated the N-related LVM Raman intensity (ILVM) and frequency (ωLVM) as a function of N concentration. Both the ILVM and the ωLVM were found to rise for the GaAs1−xNx films with higher N incorporation. It is also evident that the N concentration in the GaAs1−xNx grown films determined by Raman spectroscopy technique (xRaman) exhibits a linear dependence on the N concentrations determined by the high resolution X-ray diffraction (HRXRD) (xXRD). Our results demonstrate that the linear dependence of the xRaman on the xXRD provides a useful calibration method to determine the N concentration in dilute GaAs1−xNx films (xXRD⩽0.055).