Determination of the reduction depth of tungsten oxide thin films under the effect of proton irradiation

This work is devoted to experimental determination of the limiting reduction depth of tungsten oxide to metal by the measurement of volumetric variations in a thin film of WO₃ under the effect of proton irradiation with an energy of 1.5 keV. The method of radiation-induced reduction of tungsten from WO₃ can be used for preparation of conducting structures in a dielectric matrix and obtaining an inorganic mask for carrying out different ion-beam processes. It is shown experimentally that the effect of a proton beam with an energy of 1.5 keV provides complete reduction of a tungsten oxide layer up to 138 nm thick. The experimental ratio of the thickness of the reduced layer to the thickness of the starting oxide film was 0.31. It is shown that the limiting reduction depth of tungsten oxide is determined by the path of protons in tungsten.