1988 年 37 巻 412 号 p. 83-86
The effect of Al on the resistance against oxidation of Ti1-xAlxN films prepared by the rf-sputtering method was investigated.
ESCA spectra of the samples exposed in air for one day at room temperature showed that Ti2p3/2 peak shifted to the higher binding energy side by adding AlN and oxidation of the surface of the Al-bearning films was reduced in comparison with TiN.
The Oxidation of Ti1-xAlxN at high temperatures in O2 gas flow was examined by thermo-gravimetry. TiN was converted to TiO2 above 600°C in O2 gas flow, while the NaCl-type Ti0.65Al0.35N, Ti0.3Al0.7N (a new crystal phase) and the Wurtzite-type Ti0.15Al0.85N were stable below 800°C but oxidized at 900°C in O2 gas flow. Each oxidized sample was a mixture of TiO2, Al2TiO5, Al2O3 and AlN.
In N2 atmosphere, the NaCl-type Ti0.65Al0.35N was stable below 800°C, but decomposed to two nitrides, TiN and AlN, at 1000°C. This phase separation is surely related to the oxidation of Ti0.65Al0.35N described above.