Preparation and Properties of IrO2 Thin Films Grown by Pulsed Laser Deposition Technique

Highly conductive IrO2 thin films were prepared on Si (100) substrates by means of pulsed laser deposition technique from an iridium metal target in an oxygen ambient atmosphere. Emphasis was put on the effect of oxygen pressure and substrate temperature on the structure, morphology and resistivity of IrO2 films. It was found that the above properties were strongly dependent on the oxygen pressure and substrate t emperature. At 20 Pa oxygen ambient pressure, pure polycrystalline IrO2 thin films were obtained at substrate temperature in the 300-500 ℃ range with the preferential growth orientation of IrO2 films changed with the s ubstrate temperature. IrO2 films exhibited a uniform and densely packed granular morphology with an average feature size increasing with the substrate temperature. The room-temperature resistivity variations of IrO2 films correlated well with the corresponding film morphology changes. IrO2 films with the minimum resistivity of (42 ±6) μΩ·cm was obtained at 500 ℃.