Gallium desorption kinetics on (0001) GaN surface during the growth of GaN by molecular-beam epitaxy

Abstract

Gallium (Ga) surface desorption behavior was investigated using reflection high-energy electron diffraction during the GaN growth. It was found that the desorption of Ga atoms from the (0001) GaN surfaces under different III-V ratio dependents on the coverage of adsorbed atoms. Doing so led to desorption energies of 2.76 eV for Ga droplets, 1.24–1.89 eV for Ga under Ga-rich growth conditions, and 0.82 eV – 0.94 eV for Ga under stoichiometric growth conditions. Moreover, the variation of the GaN surface morphology under different III-V ratios on porous templates supports the conclusion that Ga desorption energy depends on the coverage, and the III/V ratio dominates the growth mode.