Chemical vapor deposition of phase-rich WC thin films on silicon and carbon substrates

Chemical vapor deposition was used to deposit tungsten carbide from a mixture of WCl6, H2 and C3H8 at 750–1050 °C on silicon and carbon substrates. The phase composition of the films was correlated with substrate temperature, substrate position in the reactor, and total flow rates. X-ray diffraction and X-ray photoelectron spectroscopy were employed to investigate the surface and bulk properties of the thin films. Thick, adherent films of phase-rich hexagonal WC were deposited using 1.3 × 103 Pa total pressure, 1050 °C substrate temperature, and reactant flow rates of H2/C3H8/Ar/WCl6 = 1.8 × 10− 2/3.6 × 10− 3/8.9 × 10− 4/1.8 × 10− 4 mol/min, where Ar is the carrier gas. The surface composition was oxygen and carbon rich as compared with the bulk.