Oxidation of Tin as investigated by X-ray Photoelectron Spectroscopy*

The oxidation of tin has been investigated by the technique of x-ray photoelectron spectroscopy. Thin films of tin were deposited on a silicon substrate by the e-beam technique. The films were oxidized in situ by exposing them to an atmosphere of oxygen at temperatures of 100, 200, 300, 400, and 500°C for various times. Aluminum x-rays (energy = 1486.6 eV) were used to record the spectra. The tin 3d and oxygen 1s core levels have been investigated. The spectral data (binding energy shift and the shape of the core level peaks) have been utilized to interpret the data. The growth of the oxide as a function of the substrate temperature and the oxygen pressure has been evaluated. The oxidation kinetics have been modelled to follow the growth of the oxide.