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

Abstract

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.