Aiming to realize a conductive passivation layer for copper interconnection, the solid-gas reactions of cobalt films with silane and with disilane to form cobalt suicides are experimentally investigated. X-ray photoelectron spectroscopy revealed that cobalt suicides layers of up to 6 nm thickness can be selectively formed in the reaction at 473-673 K within 5 min without detectable silicon deposition on silicon dioxide, a common inter-metal dielectric layer. Rapid thermal oxidation experiments revealed that the silicided cobalt layers had better anti-oxidation performance than untreated cobalt layers, and the effect of silicidation was to suppress copper out-diffusion through the cobalt layers. Because cobalt-based alloys can be selectively electroless-plated on copper, selective silicidation of cobalt layers will be easily incorporated into device processing.
|ジャーナル||Japanese Journal of Applied Physics, Part 1: Regular Papers and Short Notes and Review Papers|
|出版ステータス||Published - 2004 9 1|
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