Systematic Theoretical Investigations on Surface Reconstruction and Adatom Kinetics on AlN Semipolar Surfaces

Abstract

The surface reconstructions and adatom kinetics on AlN(1-102) and AlN(1-101) surfaces in the presence of H₂ molecules are investigated on the basis of density-functional theory calculations. Our surface phase diagram calculations demonstrate that the H-incorporated surfaces are invariably stable over the wide range of H₂ pressure. We find that under the growth condition the adsorption energy of Al adatom on AlN(1-102) surface is much larger than that on AlN(1-101) surface. Furthermore, we find that the diffusion behavior of Al adatom on AlN(1-101) surface is significantly influenced by the presence of hydrogen. These results suggest that impact of hydrogen ambient during the metal-organic vapor-phase epitaxy growth on AlN(1-102) surface is quite different from that on AlN(1-101) surface. [DOI: 10.1380/ejssnt.2015.239]