Growth and Rutherford backscattering spectrometry study of direct current sputtered indium oxide films

In2O3 thin films were grown by direct current reactive sputtering. Structural investigations using X-ray diffraction and transmission electron microscopy confirmed the single-phase and polycrystalline nature of the films. Rutherford backscattering spectrometry study of the interface of In2O3 films with Si indicated the formation of ∼20 nm thick intermediate region consisting of silicon, oxygen and indium. Annealing at 875 K in oxygen atmosphere led to an increase in interface layer thickness. Broadening of the interface and diffusion of silicon into In2O3 were observed in films annealed in argon at 875 K. Oxygen-to-indium atomic concentration ratio in the as-grown films was ∼1.44, which was found to vary depending upon the annealing conditions. However, films deposited over Si/SiO2 showed a sharp interface between the In2O3 film and SiO2.