Mechanisms of oxygen incorporation in indium–tin–oxide films deposited by laser ablation at room temperature

The use of O218 as a background gas in pulsed-laser deposition (PLD) of indium–tin–oxide (ITO) films allows clear discrimination between the two oxygen sources in the films: target and background gas. A study of both stoichiometric and electrical properties of the ITO films in terms of the relative contributions of the two oxygen sources at different background-gas pressures is presented in this work. The film with lowest resistivity (∼4×10−4 Ω cm) incorporates 28% oxygen from the background gas as compared to the total oxygen in the film. This relatively strong oxygen incorporation from the background gas suggests a strong exchange rate between O16 from the target and O18 from the background gas in the “plume” phase of the PLD process.