In$_{x}$Al$_{1-x}$N solid solutions: Composition stability issues

The phase diagrams and growth conditions of In$_{x}$Al$_{1-x}$N solid solutions by magnetron sputtering, molecular beam and gas-phase epitaxy from organometallic compounds are analyzed. Mutual equilibrium solubility in a wide range of compositions of thick layers of this solution is close to zero. Moreover, the presence of elastic misfit stresses for thin In$_{x}$Al$_{1-x}$N films narrows the unstable mixing region. Optimization of the growing conditions makes it possible to obtain the homogeneous high-quality In$_{x}$Al$_{1-x}$N layers suitable for the production of a barrier layer in an InAlN/GaN HEMT.