Influence of nitrogen in TiAlNO coatings fabricated by co-sputtering

Abstract

Nanocharacterization of titanium nitride thin films obtained by reactive magnetron sputtering V V Merie, M S Pustan, C Bîrleanu et al. Abstract. TiAlNO coatings were obtained on corning glass by means of the co-sputtering technique. Two series were fabricated. In the first one the argon flux was maintained at 12 sccm, while the nitrogen flux was varied in 3, 6 and 9 sccm; in the second one the argon flux was 15 sccm and the nitrogen flux was varied in 2, 3, 4, 5 and 6 sccm, which produced a working pressure variation. For co-sputtering in the first series, three targets were occupied: titanium, alumina and aluminium; meanwhile in the second series, two targets were used: titanium monoxide and aluminium plus an amount of titanium, specifically, 3.5 gr in the aluminium target, occupying 40% of the total effective area of the target. Structural, mechanical and electrical properties were obtained through X-ray diffraction, the Vickers microhardness test and resistivity probes, respectively. For first series, X-ray diffraction detected titanium nitride (TiN) in the crystalline phase; for the second series, aluminium nitride and titanium oxide (TiO) 3.38 . The difference in the crystalline structure obtained for the series explains the microhardness values; in the first series a maximum value of 20.4 GPa at 2 sccm of nitrogen was obtained, whereas in the second series the maximum value obtained was 8 GPa. As one can observe, the increase in nitrogen flux is not an advantage to hardness, but in electrical resistivity it has a positive effect. The results suggest that TiAlNO is versatile material that could be used for both mechanical and electronic applications; however, it is important to control fabrication conditions.