Thermal Decomposition Of Tungsten Hexacarbonyl: Cvd Of W-Containing Films Under Pd Codeposition And Vuv Assistance

Experiments on chemical vapor deposition of W(CO)(6)-derived films on silicon substrates were carried out at total pressure of 5-10 Torr within the temperature range of 250-350 degrees C in Ar or H-2 flow. Metallic, carbide and oxide phases composed the obtained films. Deposition in presence of hydrogen results in the increase of the metal content in the film. Sublimed palladium hexafluoracetylacetonate Pd(hfa)(2) was used for Pd catalytic promotion of the deposition process. Codeposition with Pd(hfa)(2) in hydrogen increases W-metal fraction and oxygen content while the Pd content is up to 10 at.%. Influence of vacuum ultraviolet (VUV) radiation from Xe excimer lamp (lambda similar to 172 nm) on the quality of the obtained films was investigated. It was found that VUV irradiation can reduce the oxygen-content in the film while W-metal fraction slightly increases. In all films, oxygen was in the form of WO3 and carbon was mainly incorporated as a graphite metastable phase. The influence of other chemical additives is discussed. (C) 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim