Theoretical approach to initial growth kinetics of GaN on GaN(0 0 1)

Abstract

We carried out theoretical analyses based on ab initio calculations incorporates in which free energy of the vapor phase is incorporated in order to determine the initial growth kinetics of c-GaN on GaN(0 0 1)-(4×1). The feasibility of the theoretical approach had been confirmed by calculations of Ga adsorption–desorption transition temperature and transition beam equivalent pressures on the GaAs(0 0 1)-(4×2) β2 surface in our previous work [Y. Kangawa, T. Ito, A. Taguchi, K. Shiraishi, T. Ohachi, Surf. Sci. 493 (2001) 178]. The results of calculations suggest that no Ga adsorption occurs on the initial surface under typical growth conditions but that a Ga adsorption site appears after N adsorption on GaN(0 0 1)-(4×1). That is, in the initial growth stage of c-GaN on GaN(0 0 1)-(4×1), a N-adsorbed structure is formed and then Ga adsorbs on the N adatom.