Structural and electrical properties of semipolar (11-22) AlGaN grown on m -plane (1-100) sapphire substrates

Semipolar III-nitrides have attracted increasing attention because of the reduced piezoelectric field in the active layer. In particular, (11-22) plane is promising due to the small polarization field along the growth axis and the epitaxial matching on m -plane sapphire. The aim of this study was to assess the effect of growth conditions on the structural and electrical properties of Si-doped (11-22) AlGaN. Semipolar AlGaN/AlN layers were grown on m -plane sapphire by metal-organic chemical vapor deposition at different temperatures, V/III ratios, and tetraethylesilane flows. Surface morphology, crystalline quality, and electrical properties of the AlGaN layers were investigated with AFM, XRD, and by Hall measurements, respectively. (© 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)