Phase Formation and Morphology of Nickel Silicide Thin Films Synthesized by Catalyzed Chemical Vapor Reaction of Nickel with Silane

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• 作者：Antony Premkumar Peter ; Johan Meersschaut ; Olivier Richard ; Alain Moussa ; Johnny Steenbergen ; Marc Schaekers ; Zsolt T艖kei ; Sven Van Elshocht ; Christoph Adelmann
• 刊名：Chemistry of Materials
• 出版年：2015
• 出版时间：January 13, 2015
• 年：2015
• 卷：27
• 期：1
• 页码：245-254
• 全文大小：863K
• ISSN：1520-5002

文摘

The synthesis of nickel silicide thin films via a vapor鈥搒olid reaction has been studied by exposing thin (10 nm) Ni films to silane (SiH₄). The crystalline phases, the Ni/Si stoichiometric ratios, as well as the surface and interface properties of the resulting silicide films were investigated as a function of the growth parameters such as the SiH₄ partial pressure, the reaction temperature, and the exposure time. At low temperature (300 掳C), SiH₄ exposure led to the self-limiting deposition of Si on Ni by catalytic decomposition of SiH₄ but not to silicate formation. Between 350 and 400 掳C, phase pure orthorhombic NiSi films were obtained that were formed directly without any apparent intermediate Ni-rich silicide phases. A transformation to NiSi₂ occurred at 450 掳C and above, and at 500 掳C phase pure NiSi₂ was obtained. Here, the transient formation of NiSi was observed that transformed into NiSi₂ for prolonged SiH₄ exposure. The results indicate that the Si solubility governs the phase formation sequence whereas kinetics are determined by Ni diffusion and the reaction rate. Resistivity values of 21 and 36 渭惟 cm were found for the NiSi and NiSi₂ thin films, respectively, corresponding to the values reported for films obtained by solid-state reactions.