Growth and characterization of epitaxial Al(sub}(1-x）In{sub}xN films grown on sapphire (0001) by plasma source molecular beam epitaxy

摘要

Epitaxial Al{sub}(1-x)In{sub}xN films (thickness ～150 nm) with 0≤x≤1 have been grown by Plasma Source Molecular Beam Epitaxy on Sapphire (0001) at a low substrate temperature of 375°C and were characterized by reflection high energy electron diffraction (RHEED), x-ray diffraction (XRD), and atomic force microscopy (AFM). Both RHEED and XRD measurements confirm the c-plane growth of Al{sub}(1-x)In{sub}xN films on sapphire (0001) with the following epitaxial relations: Nitride [0001] ‖ Sapphire [0001] and Nitride <0110> ‖ Sapphire <2 1 1 0>. The films do not show any alloy segregation. However, the degree of crystalline mosaicity and the compositional fluctuation increases with increasing In concentration. Further, AFM measurements show an increased surface roughness with increasing In concentration in the alloy films.