Mechanistic Study for Facile Electrochemical Patterning of Surfaces with Metal Oxides

Reactive interface patterning promoted by lithographic electrochemistry serves as a method for generating submicrometer scale structures. We use a binary-potential step on a metallic overlayer on silicon to fabricate radial patterns of cobalt oxide on the nanoscale. The mechanism for pattern formation has heretofore been ill-defined. The binary potential step allows the electrochemical boundary conditions to be controlled such that initial conditions for a scaling analysis are afforded. With the use of the scaling analysis, a mechanism for producing the observed pattern geometry is correlated to the sequence of electrochemical steps involved in the formation of the submicrometer structures. The patterning method is facile and adds to electrochemical micromachining techniques employing a silicon substrate.