Quantitative model for the MBE-growth of ternary nitrides

We report on a study of the growth of ternary AlGaN and InGaN by molecular beam epitaxy, leading to a quantitative model describing the alloy composit ion and growth rate as a function of group III fluxes, N flux and growth te mperature. For low growth temperatures, the composition is exclusively dete rmined by the different bond strengths between the group III elements and N , leading to a complete displacement of the more weakly bound species The I n loss from InGaN observed fop typical growth conditions is caused by therm al decomposition of the growing layer with an activation energy between 3.5 and 3.8 eV depending on the In content.