Oxidation of Thin Films of Nickel as investigated by X-ray Photoelectron Spectroscopy

Thin films of nickel were deposited on silicon substrates. The electron-beam technique was used for the deposition. The samples were oxidized in a quartz tube furnace with varying rates of flow of oxygen while the substrate was kept at a fixed temperature. The oxidation of nickel was characterized by the technique of x-ray photoelectron spectroscopy using the aluminum anode as the source of energy. The Ni 2p and O 1s core levels were recorded. The binding energy positions, the full-width-at-half maximum, and the high binding energy satellite associated with the Ni 2p core level peak were utilized to study the formation of the oxide of nickel. A curve fit to the spectral data was performed using the spectral data of elemental nickel and NiO. The amount of NiO present on the sample has been estimated from this curve fitting. The dependence of the thickness of NiO on the flow rate of oxygen has been established.