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

Abstract

Highly (111)-oriented and conformal iridium (Ir) 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 (Tsub) between 300 and 700 °C was used. At a low Tsub of 350 °C, the randomly oriented polycrystalline films exhibited an I111/I200 x-ray intensity ratio of 6. However, the films deposited at Tsub = 700 °C on native SiO2 and amorphous SiO2 surfaces were highly oriented with the I111/I200 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.

Chemical Vapor Deposition of Iridium, Platinum, Rhodium and Palladium

“…[34][35][36] Direct liquid injection may produce highly (111)-oriented iridium films on SiO 2 /Si(100) substrates. 37) Decomposition studies in a direct liquid injection CVD process revealed that the reaction temperature of (MeCp)Ir(1,5-COD) decreased from 760 K to below 465 K in the presence of oxygen gas. 37) Because of its attractive properties, decomposition of (MeCp)Ir(1,5-COD) in the absence of oxygen has been additionally studied to clarify the surface reactions that take place on a rhodium surface.…”

“…37) Decomposition studies in a direct liquid injection CVD process revealed that the reaction temperature of (MeCp)Ir(1,5-COD) decreased from 760 K to below 465 K in the presence of oxygen gas. 37) Because of its attractive properties, decomposition of (MeCp)Ir(1,5-COD) in the absence of oxygen has been additionally studied to clarify the surface reactions that take place on a rhodium surface. [37][38][39] [Ir(acetate)(1,5-COD)] 2 is the only one complex reported to yield high-purity iridium films (<1 mass%C or O) without the need of a reactive gas (either hydrogen or oxygen).…”

“…37) Because of its attractive properties, decomposition of (MeCp)Ir(1,5-COD) in the absence of oxygen has been additionally studied to clarify the surface reactions that take place on a rhodium surface. [37][38][39] [Ir(acetate)(1,5-COD)] 2 is the only one complex reported to yield high-purity iridium films (<1 mass%C or O) without the need of a reactive gas (either hydrogen or oxygen). 32) In spite of its clean decomposition, this complex inevitably produced low deposition rates (2:2 Â 10 À3 nmÁs À1 ), probably because of its relative low volatility (vapor pressure about 10 Pa at 398 K) compared with other iridium (1,5-COD)-complexes.…”

Microstructural Characterization and Mechanical Property of Iridium Coating Produced by Double Glow Plasma

“…This was due to the fact that the plane with minimum surface energy was (111); the coating was most stable if oriented toward (111). Goswami et al [20] indicated that (111)-oriented Ir coating exhibited excellent diffusionbarrier properties against oxygen. Wessling et al [21] researched the effects of incident atom energy on preferred crystallographic orientation of the MS Ir film.…”

High-performance iridium thin films for water splitting by CVD using new Ir(I) precursors

“…The ratio decreases at lower and higher deposition temperatures. For comparison, highly (111) oriented Ir thin films deposited by liquid-injection MOCVD were obtained by Goswami et al [39] attaining values as high as I111/I200 = 277 on Si(100) substrates with native oxide. This at least indicates that the predominant crystal growth proceeds along the (111) orientation parallel to the substrate for higher deposition temperatures.…”