New MOCVD precursor for iridium thin films deposition

Thin films of metallic iridium were grown by metal organic chemical vapor deposition in a vertical hot-wall reactor. The new solid compound Ir(thd)₃ (thd = 2,2,6,6-tetramethyl-3,5-heptadione) was used as the iridium source. The iridium precursor was analyzed by elemental analysis, infrared spectroscopy, ¹H NMR spectroscopy and thermogravimetry (TG). The results of TG showed that the iridium β-diketonate was found to vary with the nature of the β-diketonate group and the use of the thd led to a precursor with higher volatilities than the Ir(acac)₃ (acac = acetylacetonate) source. Deposited iridium films were characterized by X-ray diffraction (XRD) and atomic force microscopy (AFM) in order to determine crystallinity and surface morphology.