InGaN(0001) alloys grown in the entire composition range by plasma assisted molecular beam epitaxy

Abstract Indium gallium nitride alloy (0001) films in the entire composition range were grown heteroepitaxially by radio‐frequency plasma assisted molecular beam epitaxy on Ga‐polarity GaN(0001)/Al₂O₃ substrates. A growth approach based on low substrate temperatures and near‐stoichiometric growth conditions was followed. Under these conditions incorporation efficiency of indium atoms was equal to one. X‐ray diffraction data reveal that phase separation phenomena were effectively suppressed. As the indium mole fraction increased, a tendency of the strain state of the films to change from compressive to tensile was observed. This was attributed to growth through nucleation and coalescence of three‐dimensional InGaN islands with high lattice mismatch on GaN(0001). (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)