Growth behavior and thermal stability of epitaxial $CoSi2$ layer from cobalt–carbon films on (100) Si substrate

A uniform epitaxial $CoSi2$ layer was grown on (100) Si substrate by rapid thermal annealing at $800 °C$ in $N2$ ambient without capping layers from an amorphous cobalt-carbon film. The amorphous cobalt-carbon film was deposited on Si substrate by the pyrolysis of cyclopentadienyl dicarbonyl cobalt, $Co(η5–C5H5)(CO)2,$ at $350 °C.$ The discrete epitaxial $CoSi2$ layers with {111} and (100) faceted interfaces were formed on (100) Si substrate at the initial stage of reaction between Co and Si. Annealing at elevated temperatures lowered the roughness of the $CoSi2/Si$ interface. The leakage current measured on the junction, fabricated with the epitaxial $CoSi2$ layer and annealed at $1000 °C$ for 30 s, was as low as that of the as-fabricated junction without silicide. The result indicates that epitaxial (100) $CoSi2$ is thermally stable at temperatures even above $1000 °C$ and has potential application to the salicide process in subhalf micron devices.