Characterization of molecular beam epitaxy grown β-Nb_2N films and AlN/β-Nb_2N heterojunctions on 6H-SiC substrates

摘要

β-Nb_2N films and AlN/β-Nb_2N heterojunctions were grown by molecular beam epitaxy (MBE) on 6H-SiC. The epitaxial nature and β-Nb_2N phase were determined by symmetric and asymmetric high-resolution X-ray diffraction (HRXRD) measurements, and were confirmed by grazing incidence diffraction measurements using synchrotron photons. Measured lattice parameters and the in-plane stress of β-Nb_2N on 6H-SiC were c = 5.0194A, a = 3.0558A, and 0.2GPa, respectively. The HRXRD, transmission electron microscopy, and Raman spectroscopy revealing epitaxial growth of AlN/β-Nb_2N heterojunctions have identical orientations with the substrate, abrupt interfaces, and bi-axial stress of 0.88 GPa, respectively. The current finding opens up possibilities for the next generation of high-power devices that cannot be fabricated at present.