Deposition of tungsten in methane atmosphere using a low energy plasma focus device

Abstract

Deposition of tungsten in methane atmosphere was performed using a low energy plasma focus device. The resulting compounds were synthesized and investigated during the deposition process. Carbon-rich contamination was identified as an organic viscous liquid crystal defect. Tungsten carbide (W2C) and dark-black oxygen-deficient tungsten trioxide (WO3-x) thin films were synthesized by plasma focus device using different number of focused shots. The synthesis of each thin film, which was dependent upon operation of plasma focus device was verified and discussed. Tungsten carbide W2C was synthesized during the deposition process while the dark-black WO3-x was created after the deposition process in atmosphere. All compounds were investigated by spectroscopy, crystalline, and microscopy methods. Nano indentation test disclosed higher value of hardness for the film containing tungsten carbide compound (10.01 GPa) compared to both pure tungsten (5.72 GPa) and the dark-black WO3-x thin film (6.83 GPa). The verified band gap energy of dark-black WO3-x was around 1.475 eV.