Growth model for plasma-assisted molecular beam epitaxy of N-polar and Ga-polar InxGa1-xN

Nath D. N., Guer E., Ringel S. A., Rajan S.

JOURNAL OF VACUUM SCIENCE & TECHNOLOGY B, vol.29, no.2, 2011 (SCI-Expanded) identifier identifier


The authors have developed a comprehensive model for the growth of N-polar and Ga-polar InxGa1-xN by N-2 plasma-assisted molecular beam epitaxy. GaN films of both polarities were coloaded and InxGa1-xN was grown in the composition range of 0.14 < x < 0.59 at different growth temperatures keeping all other conditions identical. The compositions were estimated by triple-axis omega-2 theta x-ray diffraction scans as well as by room temperature photoluminescence measurements. The dependence of the In composition x in InxGa1-xN on growth temperature and the flux of incoming atomic species is explained using a comprehensive growth model which incorporates desorption of atomic fluxes as well as decomposition of InN component of InxGa1-xN. The model was found to be in good agreement with the experimental data for InxGa1-xN of both polarities. A N-polar In0.31Ga0.69N/In0.05Ga0.95N multi-quantum-well structure grown with conditions predicted by our growth model was found to match the compositions of the active layers well besides achieving a smooth surface morphology at the quantum-well/barrier interface. The understanding of growth kinetics presented here will guide the growth of InxGa1-xN for various device applications in a wide range of growth conditions. (C) 2011 American Vacuum Society. [DOI: 10.1116/1.3562277]