Cobalt Metallorganic Chemical Vapor Deposition and Formation of Epitaxial CoSi2 Layer on Si(100) Substrate

An epitaxial CoSi 2 layer was grown on Si(100) substrate by the diffusion of Co from a cobalt‐carbon film without the use of an interlayer, which is usually required between the Si and cobalt layers for the formation of epitaxial CoSi 2 layers. Co‒C and pure Co layers were deposited by metallorganic chemical vapor deposition using the Co precursor cyclopentadienyl dicarbonyl cobalt, Co ( η 5 ‐ C 5 H 5 ) ( CO 2 ) , and cobalt carbonyl, Co 2 ( CO 8 ) , at 350 and 200°C, respectively. The CoSi 2 layer was epitaxially grown on Si(100) substrate from Co‒C by ex situ rapid thermal annealing at 800°C in N 2 ambient. However, the polycrystalline CoSi 2 layer was formed from pure Co film under the same annealing conditions. The supply of Co to the interface by diffusion in the Co‒C film seems to be lower enough than in the pure Co film, resulting in an epitaxial CoSi 2 layer on Si(100) substrate.