Kinetics of deposition of Cu thin films in supercritical carbon dioxide solutions from copper bis͑di-isobutyrylmethanate͒ ͕Cu͓͑CH 3 ͒ 2 CH͑CO͒CH͑CO͒CH͑CH 3 ͒ 2 ͔ 2 ͖, Cu͑dibm͒ 2 ͒, a F-free copper͑II͒ complex, via hydrogen reduction were studied. A flow-type reaction system was employed to control each deposition parameter independently and at a constant value. Apparent activation energies for Cu growth were determined for a temperature range of 200-260°C as a function of hydrogen concentration.The determined values varied from 0.35 to 0.63 eV and decreased as hydrogen concentration increased. At a deposition temperature of 200°C, growth rate followed a Langmuir-type dependence against Cu͑dibm͒ 2 and hydrogen concentrations, showing first-order dependence at lower concentrations and zero-order dependence at higher concentrations. At a higher deposition temperature of 240°C, no saturation in the growth rate was observed. A Langmuir-Hinshelwood-type growth mechanism was discussed, and a rate equation for growth was proposed, taking into account the temperature dependence of both the rate constant of the rate-determining reaction and adsorption equilibrium constants. The hydrogen concentration dependence of the apparent activation energy for Cu growth was discussed with this rate equation.
A novel selective and bottom-up deposition process from supercritical CO2 is proposed and demonstrated. Supercritical CO2 fluids are dense media, and a deposition precursor dissolving wherein can easily condences in hollow/concave features. By combining this capillary condensation phenomenon with proper reaction chemistry, it was realized to deposit Ru an Cu in holes and trenches structures preferentially. The capillary condensation occurs better in the narrower features, we call this method “gtopography-sensitive” selective deposition technique.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.