Ab initio Analysis of Surface Structure and Adatom Kinetics of Group-III Nitrides

Recent results based on density-functional theory calculations concerning the structure and stability of group-III nitride surfaces are discussed. An analysis of the thermodynamically stable surface structures for this materials system reveals that the driving mechanisms behind surface reconstructions are fundamentally different to those in ‘traditional” (i.e. arsenic or phosphorus based) III–V semiconductors. Specifically, surfaces are always metal-rich and nitrogen atoms on and in the surface layer are thermodynamically unstable. This feature will be shown to have important consequences on surface morphology, adatom kinetics, growth, reactivity, and alloy formation.