Growth, Structural, and Electrical Characterizations of N-Polar InAlN by Plasma-Assisted Molecular Beam Epitaxy

N-polar In x Al 1- x N (0.02 < x < 0.65) films were grown and characterized by plasma-assisted molecular beam epitaxy (PAMBE). Indium incorporation in the films was characterized both as a function of the impinging In and Al flux and the growth temperature. In incorporation in the film was found to decrease with increasing growth temperature ( T gr ) for T gr > 560 °C. A smooth surface morphology was obtained for In 0.18 Al 0.82 N lattice-matched to GaN. Subsequently, N-polar In 0.18 Al 0.82 N was used as a charge-inducing barrier in a N-polar GaN HEMT structure and electrical characterizations including current–voltage ( I – V ) measurements were performed.