METAL-ORGANIC CHEMICAL-VAPOR-DEPOSITION OF COPPER-CONTAINING PHASES - KINETICS AND REACTION-MECHANISMS

The mechanisms and kinetics of the deposition processes of Cu-O phases by chemical vapor deposition from the Cu(acac)(2) precursor were studied under Ar/O-2 in a horizontal flow, low-pressure MOCVD reactor. The nature and the deposition rate of films were determined under different operating conditions (e.g., reactant composition, substrate temperature, and carrier gas flow rate). Fully oxidized CuO films with no carbon contamination were deposited at 723 K and above using O-2/Cu(acac)(2) mole ratios greater than or equal to 10(3). Lower temperatures (in the range 523-723 K) and/or lower O-2/Cu(acac)(2) mole ratios (in the range 10-10(3)) gave films of mixed Cu/Cu2O/CuO composition. The deposition rate under higher temperatures (>593 K) was linearly dependent on the Cu(acac)a partial pressure. Below this temperature, a saturation limit was approached by increasing the partial pressure. The saturation limit, in turn, was found to increase linearly with the oxygen partial pressure. The dependence of copper deposition rate on the substrate temperature was also investigated and an activation energy value of 48 +/- 6 kJ/mol was obtained. The proposed reaction mechanism is based on a dissociative adsorption process of Cu(acac)(2) on active surface sites, followed by copper oxidation and ligand decomposition.