We have investigated the feasibility that low pressure chemically vapour deposited W can be used as a gate electrode material of metal-oxide-semiconductor (MOS) field effect transistors. We improved adhesion of the W film to SiO2 by using a pulsing injection of source gas. The pulsing injection of the reactant gas enhances the desorption of byproduct gases from the surface of the growing film and thus more W nuclei formed on SiO2. Tungsten thin films were deposited on the SiO2/Si with a deposition rate of 1000-2000 Angstrom min(-1). The deposition was carried out at various temperatures of 300-750 degrees C and various SiH4:WF6 ratios of 0.6-1.5. The higher adhesion strength and resistivity of W thin films were achieved at the higher SIH4:WF6 ratio and higher deposition temperature. X-ray diffraction analysis showed that the crystal structure of all W films, deposited at various temperatures, was alpha-W in spite of either high reactant gas ratio or high temperature. Since W thin films had good adhesion to SiO2, MOS structure capacitors were fabricated with a W electrode via wet chemical processes and their electrical properties were also characterized. The extreme value distribution function of dielectric breakdown strength indicates that the thin SiO2 layer was significantly degraded by the diffused F ions. However, the stacked gate dielectric of SiO2 and Si2N4 layers instead of the single SiO2 layer was not degraded by the W gate electrode, since the Si3N4 layer protected SiO2 from chemical attack or restricted the F diffusion during deposition of the W gate electrode.