Study of GaAsBi MOVPE growth on (1 0 0) GaAs substrate under high Bi flow rate by high resolution X-ray diffraction

GaAsBi alloy was grown on (1 0 0) GaAs substrate by metalorganic vapour phase epitaxy. GaAsBi film was elaborated with V/III ratio of 9.5, trimethyl bismuth molar flow rate of about 3 μmol/min and a growth temperature of 420 °C. The surface morphology of GaAsBi alloy was investigated by means of scanning electron microscopy and atomic force microscopy. Results show surface Bi droplets formation. High-resolution X-ray diffraction (HRXRD) curves present more diffraction peaks other than that of GaAs substrate. Detailed HRXRD characterization shows that diffraction peaks splitting do not represent a crystallographic tilting with respect to GaAs substrate. Diffraction patterns also show a remarkable stability of the alloy against thermal annealing.