Indium Tin Oxide Thin Films Deposited at Low Temperature Using Dual Ion Beam Sputtering

ITO samples were sputtered at room temperature by ion assisted dual ion beam sputtering using atomic or molecular oxygen. The electrical properties appear to depend on the oxygen flow rate during deposition and the resistivity decreases for samples sputtered at a higher oxygen flow rate (1–5 sccm). The resistivity is lowest at an oxygen flow rate of 4 sccm. The average absorption in the visible part of the spectrum also decreases as a function of the oxygen flow rate and is lower for samples sputtered with atomic oxygen. The figure of merit, i.e. the ratio of the conductivity versus the average absorption in the visible range, increases for higher oxygen flow rates and is typically 20–60% higher for samples sputtered using an atomic oxygen assist beam.