Growing IrO₂ Film On Silicon Substrate By Pulsed Laser Deposition

IrO₂ thin films are deposited by pulsed laser deposition(PLD) on silicon(100) substrate in this paper. By investigating the effects of deposition parameters such as the O₂ pressure, the substrate temperature, the laser output energy, the distance of the substrate to the target and the annealing temperature on the structure and the performance of IrO₂ thin films, high quality have been obtained . The result shows that: all deposition parameters have great effect on the orientation and the structure of the films. Low O₂ pressure will result in impure polycrystalline IrO₂ thin films. And the substrate temperature, the laser output energy, the distance of the substrate to the target and the annealing temperature will influence the orientation and the morphology of the films. By exploring the growing conditions of the IrO₂ thin films, optimum parameters have been identified: O₂ pressure 20Pa, substrate temperature 500℃, laser output energy 140mJ, distance of the substrate to the target 50mm, annealing temperature 700⁷50℃. The films are analyzed with XRD, SEM and AFM which show that the film deposited in optimum parameters grows with a prominent (101) orientation, uniform thickness, clear interface, good adherence to the substrate and 3.9nm surface roughness. Using four probes method shows that its electrical resistivity can reach a low value of 37±1.5μO·cm, which approaches to the bulk single crystal IrO₂ thin film. It can be used as electrode material.