CHARACTERISATION OF TI-W-C THIN FILMS DEPOSITED BY CVD

摘要

Ti-W-C thin films were deposited on stainless steel substrates (440C) by chemical vapour deposition (CVD) in a horizontal hot-wall reactor from the TiCl_4-W(CO)_6-CH_4-H_2-Ar gaseous mixture, by varying the (TiCl_4+W(CO)_6)/CH_4 inlet ratios (0.53-6.5), temperature(1050℃) and reactor pressure (1 - 150 torr). The structure of the Ti-W-C thin films was characterized using X-ray diffraction (XRD). The lattice constant of the Ti-W-C films shifts from that of TiC to WC_(1-x) with increasing W concentration in the thin films. A morphological analysis was carried out using scanning electron microscopy (SEM). It was found that the surface morphology was associated 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 microhardness obtained by nanoindentation was increased up to 34Gpa. The study of transmission electron microscopy (TEM) reveals the detailed microstructure of the Ti-W-C thin films.