Elimination of columnar microstructure in N-face InAlN, lattice-matched to GaN, grown by plasma-assisted molecular beam epitaxy in the N-rich regime

The microstructure of N-face InAlN layers, lattice-matched to GaN, was investigated by scanning transmission electron microscopy and atom probe tomography. These layers were grown by plasma-assisted molecular beam epitaxy (PAMBE) in the N-rich regime. Microstructural analysis shows an absence of the lateral composition modulation that was previously observed in InAlN films grown by PAMBE. A room temperature two-dimensional electron gas (2DEG) mobility of 1100 cm(2)/V s and 2DEG sheet charge density of 1.9 x 10(13) cm(-2) was measured for N-face GaN/AlN/GaN/InAlN high-electron-mobility transistors with lattice-matched InAlN back barriers. (C) 2014 AIP Publishing LLC.