Authors: F. Zhang, R. Barrowcliff, G. Stecker, D. Wang and S-T Hsu
Affilation: Sharp Labs of America, Inc., United States
Pages: 623 - 626
Keywords: IrO2, nano rods, nano tubes, nano wires, MOCVD, wingle crystal, IV
This paper will discuss the deposition of IrO2 nano structures using (methycycpentadienyl) (1, 5-cyclooctadiene) iridium as the precursor and using Metal Organic Chemical Vapor Deposition (MOCVD) method with no template. Three different shapes of IrO2 nano structures have been successfully synthesized: they are IrO2 nano rods, IrO2 nano tubes and high aspect ratio IrO2 nano wires. SEM pictures show that the nanorods are densely aligned vertically. The hollowed nano tubes were actually formed by four nano rods grown in clusters. High aspect ratio of IrO2 nano wires with naturally formed sharp tips are about 10-50nm in diameter and 1-2 um long. We also realized selective growth of IrO2 nano wires by optimizing the catalyst layer. Low and high resolution TEM revealed that the IrO2 nano rods and nano tubes are polycrystalline structure with dislocations and defects. But the IrO2 nano wires are perfect single crystals structure with  orientation and sharp tips about 5nm. Electrical measurements show the IrO2 nano wires are metallic conductive with resistivity at the range of 300 - 400 uohm-cm. The temperature dependence of resistivity of the IrO2 nanowire was around 3 x10-3 K-1. Detailed processing conditions to form these different structures will be presented.