Highly (111)-oriented and conformal iridium films by liquid source metalorganic chemical vapor deposition

Highly (111)-oriented and conformal iridium (It) films were deposited by a liquid source metalorganic-chemical-vapor-deposition process on various substrates. An oxygen-assisted pyrolysis of (methylcyclopentadienyl) (1,5-cyclooctadiene) Ir precursor at a wide range of substrate temperatures (T-sub) between 300 and 700 degreesC was used. At a low T-sub of 350 degreesC, the randomly oriented polycrystalline films exhibited an I-111/I-200 x-ray intensity ratio of 6. However, the films deposited at T-sub = 700 degreesC on native SiO2 and amorphous SiO2 surfaces were highly oriented with the I-111/I-200 ratios of 277 and 186, respectively. The transmission electron microscopy study revealed continuous, dense, and faceted microstructures of Ir films. Also, the step coverage of Ir on TiN (64%) was higher than that on amorphous SiO2 (50%) surfaces.