Low temperature chemical vapor deposition of tungsten carbide for copper diffusion barriers

摘要: Abstract Tungsten carbide films were grown by chemical vapor deposition using W(CO) 6 and C 2 H 4 between 250 450°C. Pyrolysis studies indicate thermally decomposes over the 150–200°C temperature range with or without ethylene. Carbon incorporation increased from 13 to ∼33% when was co-fed . The W/C carbon ratio, as established X-ray photoelectron spectroscopy (XPS), remained approximately 2:1 regardless of flow ratio for temperatures 250° Films (50 nm thick) at 290°C have a resistivity μΩ-cm. Above 500°C, decreased ∼1:1.25 535 tungsten are present in state. X-Ray diffraction, XPS, selected area electron diffraction transmission microscopy analysis reveal mixture 5–6 W crystallites an amorphous matrix, whose stoichiometry is ∼2:1 W/C. Copper not found diffuse through 7-nm-thick Cu/WC/SiO stacks that annealed 400°C 8–9 h.