METASTABLE SINGLE-PHASE POLYCRYSTALLINE ALUMINUM OXYNITRIDE FILMS GROWN BY MSIP - CONSTITUTION AND STRUCTURE

By means of physical vapor deposition, a variety of metastable phases can be deposited due to the low substrate temperatures. Results are re ported on the preparation of homogeneous metastable Al-O-N layers prod uced by reactive magnetron sputtering ion plating using an Al target a nd an Ar-O-2-N-2 gas mixture. At 190 degrees C substrate temperature a nd variable gas pressures of O-2 and N-2 a variety of coatings with di fferent O and N content were prepared and analyzed by means of X-ray p hotoelectron spectroscopy, Auger electron spectroscopy, high-resolutio n transmission electron microscopy and high-resolution scanning electr on microscopy. Oxygen-rich Al-O-N phases were found to be nanocrystall ine with a cubic structure like gamma-Al2O3 (spinel), nitrogen-rich ph ases displayed a hexagonal structure like AlN (wurtzite). Around O/N=1 .5 the phase was TEM amorphous.