Preparation of composite and compositionally graded TiC–TiN films by liquid injection plasma-enhanced CVD

Composite and compositionally graded (CGed) TiC–TiN films were prepared on a Si(100) wafer substrate at about 800 °C by a plasma-enhanced chemical vapor deposition (PECVD) technique involving the injection of titanium tetra-ethoxide solutions stabilized with tri-ethanol amine into a thermal Ar/N2/H2 plasma. TiC–TiN films with various compositions of C and N were prepared by changing the N2 flow rate from 0 to 500 ml/min. Scanning electron microscopy (SEM) showed that the films were about 0.7 μm thick consisting of particles of ∼100 nm in size at a flow rate of 0 ml, the particles increasing to ∼500 nm at the higher flow rates. X-ray diffractometry (XRD) and X-ray photoelectron spectroscopy (XPS) showed that the 1.7 μm thick CGed TiC–TiN films consisted of monolithic TiC and TiN phases on the surface and substrate, respectively, with a corresponding complementary change of C and N as a function of distance from the interface.