We present the epitaxial growth by rf reactive sputtering of aluminum nitride on Si(111) at high temperature. The grain size of the obtained films was sufficient to obtain a good low energy electron diffraction (LEED) pattern from which we determined a lattice parameter of 3.1 Å, indicative of fully relaxed films. The surface of the film was examined in situ by Auger electron spectroscopy (AES); no contamination was detected, with the exception of low levels of oxygen. The film and its interface were studied by high resolution electron energy loss spectroscopy (HREELS), x-ray photoelectron spectroscopy (XPS) depth profiling, and transmission electron microscopy (TEM). Again, a low concentration of oxygen and no carbon contamination were detected by XPS. Three different growth methods were applied to the deposition of aluminum nitride at high temperature. The obtained films were studied in order to determine the influence of the methods on the interface, on the ‘bulk structure’ of the film, and on its surface. Each has been shown to have particular characteristics. The first one, performed at a temperature of 1000 °C, and including a cleaning of the surface by exposure to Al flux, was characterized by an interfacial layer with no long-range order and increasing the interaction between the film and the substrate. The second growth consisting of deposition at the same high temperature has shown a good surface quality for very thin layers (<50 Å ) and the absence of an interfacial layer. The last method, based on a first step of growth at low temperature (700 °C), resulted in good quality thick layers which allowed us to determine the infrared dielectric constants of aluminum nitride by HREELS.
Effect of Aluminum Nitride Buffer Layer Deposited by Molecular Beam Epitaxy on the Growth of Aluminum Nitride Thin Films Deposited by DC Magnetron Sputtering Technique