Fabrication and characterization of NbN, AlN and NbN/AlN/NbN on MgO substrates

At ambient substrate temperatures, NbN and AlN thin films as well as NbN/AlN/NbN sandwiches are prepared on single crystal MgO substrates, using direct current (dc) or radio frequency (RF) magnetron sputtering techniques. Excellent single crystal orientations of these structures are revealed by x-ray diffraction and transmission electron microscopy (TEM), while x-ray photoelectron spectroscope (XPS) shows that the stoichiometric composition of the NbN films is 1: 0.9 (Nb:N). Furthermore, AFM (atomic force microscope) scans indicate a root mean square (rms) roughness of 0.755 nm for AlN/NbN, and 0.83 nm for AlN, both over an area of 5 mum x 5 mum.