Chemical vapor deposition of Ti-W-C thin films

Ti-W-C thin films were deposited on stainless steel substrates (440C) by chemical vapor deposition (CVD) in a horizontal hot-wall reactor from a TiCl4-W(CO)(6)-CH4-H-2-Ar gaseous mixture, at 1323 K and at pressures ranging from 0.13 to 20.00 kPa. The structures of the Ti-W-C thin films were characterized using X-ray diffraction (XRD). The lattice constant of the Ti-W-C films shifts from that of TiC to WC1-x with increasing W concentration in the thin films. A morphological analysis was carried out using scanning electron microscopy (SEW It was found that the surface morphology varied with the W concentration and total flow. Compositional studies and binding characteristics in the Ti-W-C Films were investigated by X-ray photoelectron spectroscopy (XPS). The associated hardness measured by nano-indentation ranged from 23 to 32 GPa. The studies of transmission electron microscopy (TEM) and selected area diffraction (SAD) reveal the detailed microstructure of the Ti-W-C thin films and the presence of a WC phase. (C) 2001 Elsevier Science B.V. All rights reserved.