Oxygen Sensors Based on Thin Films of Gallium Oxide Modified with Silicon

Abstract

The results of an investigation of the electrical resistivity of Ga2O3 thin films modified with silicon under the influence of oxygen in the range of O2 from 9 to 100 vol. % and changes in the heating temperature of structures from 25 to 700 °C were presented. Thin films of Ga2O3 were obtained by RF magnetron sputtering of Ga2O3 targeted with pieces of Si on the target’s surface in oxygen–argon plasma. The possibility of developing selective oxygen sensors based on thin films Ga2O3 modified with silicon with a temperature of maximum response 400 °C was shown. Oxygen influence leads to a reversible increase in the samples’ resistance, due to the chemisorption of oxygen on the surface of thin Ga2O3 films. An increase in the response of sensors based on the thin polycrystalline films of gallium oxide modified with silicon is caused an increase in the adsorption centers for O−, due to an increase in the surface inhomogeneity and the appearance of additional adsorption centers Si4+.