Influence of the O/C ratio in the behaviour of TiCxOy thin films

Abstract

The main purpose of this work consists in the preparation of single layered titanium oxycarbide, TiCxOy, thin films. The obtained results show that the evolution of the different elements concentration with the oxygen flow can be divided into 3 different regimes -- i) carbide, zone I, ii) transition, zone T, and iii) an oxide one, zone II. Structure characterization results showed that the films crystallize in a TiC B1-NaCl-type crystal structure in the carbide regime. The films within the transition zone show a progressive tendency for amorphization, with the co-existence of a mixture of both poorly crystallized fcc TiC and TiO phases. For the highest oxygen flows, the films are practically amorphous. A broad range of colours was obtained from golden to metallic with different brilliances. An increase in hardness within the carbide zone was observed with increasing oxygen flow up to 1.5 sccm, and then followed by a systematic decrease with increasing oxygen flows.