Kinetics of deposition of Cu thin films in supercritical carbon dioxide solutions from copper bis(di-isobutyrylmethanate) {Cu[(CH3)(2)CH(CO)CH(CO)CH(CH3)(2)](2)}, Cu(dibm)(2)), a F-free copper(II) 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 degrees 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 degrees C, growth rate followed a Langmuir-type dependence against Cu(dibm)(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 degrees 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.