2002 Volume 66 Issue 3 Pages 176-181
We have investigated the initial oxidation process of Cu(001) surface and the role of translational energy of incident O2 on the initial oxidation using supersonic molecular beam techniques. In the initial oxidation, the Cu(001) surface is oxidized in a layer-by-layer manner up to one monolayer, followed by forming the Cu2O epitaxial islands on the layer. At the initial stage of the layer-by-layer oxidation, a direct activated dissociation of O2 is a dominant process and the process is promoted by the increasing translational energy of incident O2. At the stage of the subsequent oxidation in which the Cu2O islands are formed on the oxide layer, dissociative adsorption of O2 proceeds by thermal activation via a trapping precursor and the process is promoted by the decreasing translational energy of the incident O2 and/or by increasing surface temperature. Our results demonstrate that the initial oxidation can be controlled by the adjustment of the translational energy of incident O2.
