Chemical vapor deposition of cobalt using novel cobalt(I) precursors

The deposition of cobalt thin films from cobalt hydride complexes, HCo[P(OR)₃]₄, where R = methyl, ethyl, i-propyl, and n-butyl, by a chemical vapor deposition method is reported. The new cobalt precursors deposited high-purity cobalt films at substrate temperatures as low as 300 °C without employing hydrogen. The deposited Co films showed smooth and dense surface morphology. The microstructure and growth rate of the deposited films depended on the reaction conditions such as substrate temperature and precursor feed. No gas phase reactions were observed during the deposition process.