Reactive Deposition of Cobalt and Nickel Films from Their Metallocenes in Supercritical Carbon Dioxide Solution

High-purity Co and Ni thin films were deposited directly onto the native oxide of Si wafers and onto TaN and TiN films supported on Si wafers by the hydrogen reduction of their respective metallocenes in supercritical CO2 solution using a batch, cold-wall chemical fluid deposition (CFD) reactor. For Co deposition from bis(cyclopentadienyl)cobalt, substrate temperatures ranged between 285 and 320 C and reactor pressures were 220-260 bar. For Ni deposition from bis(cyclopentadienyl)nickel, substrate temperatures were 175-200 C and reactor pressures were 190-230 bar. In all cases, the reactor wall temperatures were maintained between 90 and 120 C, restricting the depositions to the heated substrates only. The deposited films were characterized by SEM, XRD, and XPS. The films were found to be essentially free from ligand-derived contamination.