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 degrees C in N-2 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(eta(5)-C5H5)(CO)(2), at 350 degrees 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 degrees 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 degrees C and has potential application to the salicide process in subhalf micron devices. (C) 1999 American Institute of Physics. [S0021-8979(99)05618-2].