Iridium Metal Thin Films and Patterned IrO2 Nanowires Deposited Using Iridium(I) Carbonyl Precursors

Abstract Highly volatile iridium(I) carbonyl complexes ( 1 – 5 ) with three anionic fluorinated chelates, namely ketoiminate, aminoalkoxide, or iminoalkoxide, have been synthesized and their physical properties relevant to CVD are evaluated. A single‐crystal X‐ray diffraction (XRD) study on Ir(CO) 2 (amakNMe 2 ) ( 3 ) confirms a square‐planar geometry with two cis‐orientated carbonyl ligands. Metallic iridium, polycrystalline IrO 2 thin films, or even patterned IrO 2 nanowires are deposited using Ir(CO) 2 (hfdaN n Pr) ( 5 ) as the CVD precursor. A systematic investigation of the deposition of IrO 2 nanowires is conducted, showing a close correlation of observed crystallite morphology with applied system pressure, underlying growth surface, and deposition temperature. Of particular importance, tilted and vertically aligned IrO 2 nanowires are obtained on LiTaO 3 (012) and LiNbO 3 (100) surfaces under a pressure of 30 Torr of oxygen at 425 °C. The morphology and structural composition of the IrO 2 are confirmed by scanning electron microscopy, transmission electron microscopy, X‐ray photoelectron spectroscopy, and XRD analyses.