Physicochemical Analysis of Mo Films Deposited by RF Magnetron Sputtering at Various Oxygen Ratios

Abstract

The results of deposition and physicochemical characterization of molybdenum thin films are described in this thesis. The physical and chemical properties of Mo oxide films were examined with X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS) techniques. The obtained Mo films at the oxygen ratio of 0% showed crystallinity of cubic Mo(110) phase. After the oxygen ratio increased more than 5% in the sputter gas, the Mo oxide films were formed as an amorphous phase. The thickness of the thin film was drastically decreased from 1000 to ca 70 nm after introduction of oxygen in the sputter gas confirmed by spectroscopic ellipsometry (SE) and scanning electron spectroscopy (SEM). The calculated band gap of the film increased from 3.17 to 3.63 eV by addition of oxygen in the sputter gas. XPS results revealed that the ratio of metallic Mo species in the Mo oxide films decreased but the contents of Mo6+ species increased as the ratio of oxygen increased in the sputter gas and fully oxidized at low content of oxygen in the sputter gas.