Effect of Solvent on the Growth of Co and Co2C Using Pulsed-Spray Evaporation Chemical Vapor Deposition

Cobalt and cobalt carbide films were obtained using chemical vapor deposition (CVD) at low pressure in a hydrogen-free atmosphere at temperatures below 300 °C. Although the growth over bare glass was enabled, the use of a 5 nm nickel seed layer improves the morphology and eliminates the incubation time. The pulsed-spray evaporation using alcohol solutions of cobalt acetylacetonate as a liquid feedstock allows the growth of metallic cobalt or cobalt carbide, depending on the choice of the alcohol and of the deposition temperature. The growth of Co 2 C was obtained, for the first time with CVD, using an ethanol precursor solution at temperatures in the range of 205–230 °C, whereas the deposition of high-quality metallic crystalline cobalt is attained with an n -propanol precursor solution at substrate temperatures above 250 °C. The obtained metallic films reach a near-bulk electrical resistivity for thicknesses above 300 nm.