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 sub strates. An oxygen-assisted pyrolysis of (methylcyclopentadienyl) (1,5-cycl ooctadiene) 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 inte nsity ratio of 6. However, the films deposited at T-sub = 700 degreesC on n ative SiO2 and amorphous SiO2 surfaces were highly oriented with the I-111/ I-200 ratios of 277 and 186, respectively. The transmission electron micros copy study revealed continuous, dense, and faceted microstructures of Ir fi lms. Also, the step coverage of Ir on TiN (64%) was higher than that on amo rphous SiO2 (50%) surfaces.