We review the surface stability and growth kinetics of III-V and III-nitride semiconductors. The theoretical approach used in these studies is based on ab initio calculations and includes gas-phase free energy. With this method, we can investigate the influence of growth conditions, such as partial pressure and temperature, on the surface stability and growth kinetics. First, we examine the feasibility of this approach by comparing calculated surface phase diagrams of GaAs(001) with experimental results. In addition, the Ga diffusion length on GaAs(001) during molecular beam epitaxy is discussed. Next, this approach is systematically applied to the reconstruction, adsorption and incorporation on various nitride semiconductor surfaces. The calculated results for nitride semiconductor surface reconstructions with polar, nonpolar, and semipolar orientations suggest that adlayer reconstructions generally appear on the polar and the semipolar surfaces. However, the stable ideal surface without adsorption is found on the nonpolar surfaces because the ideal surface satisfies the electron counting rule. Finally, the stability of hydrogen and the incorporation mechanisms of Mg and C during metalorganic vapor phase epitaxy are discussed.

The structure and stability of a polarity inversion boundary in sputtered AlN films with face-to-face annealing are investigated on the basis of scanning transmission electron microscop (STEM) and density functional theory (DFT) calculations. The high-resolution STEM observation around the AlN/sapphire interface for 200 nm sputtered AlN films with annealing at 1700 °C reveals that the polarity inversion boundary whose thickness is around 1 nm appears 10 nm above the AlN/sapphire interface. The calculated interface energies by DFT calculations also reveal that the oxide inversion boundary with Al vacancies is stabilized when the thickness of the inversion boundary is more than 1.1 nm. These results suggest that the formation of weak Al–Al bonds as well as stable Al–O bonds is crucial for the polarity inversion of AlN.

First principles full-potential linearized augmented plane wave (FLAPW) calculations and Monte Carlo simulations were performed to determine the magnetic structures in Mn-doped transition metal chalcogenides, ${\mathrm{Cr}}_{1-x}{\mathrm{Mn}}_x\mathrm{Se}$ and ${\mathrm{Cr}}_{1-x}{\mathrm{Mn}}_x\mathrm{Te}$, with the zincblende structure. A ferrimagnetic structure with excellent half-metallicity appears in the Mn 0.25 composition, where the Mn moments tend to align in an opposite orientation to the Cr moments so as to retain the half-metallicity, and the half-metallic gap is enhanced. Here, the ${\mathrm{Cr}}_{0.75}{\mathrm{Mn}}_{0.25}\mathrm{Se}$ alloy is predicted as a promising candidate as a high Curie temperature half-metallic ferrimagnet, with the tendency toward an atomic ordering of Cr and Mn atoms, that may be feasible in epitaxial growth that is thick enough for spintronic applications.