Direct patterning of metal oxides by hard templates and atomic layer deposition

We describe a procedure for one-step patterning of thin films of metal oxides (TiO₂, Al₂O₃, and ZnO) using reusable hard templates and atomic layer deposition (ALD). This procedure, called contact area lithography (CAL), was inspired from an idea of pattern transfer at a contact area, which realises high patterning fidelity, and enables a universal approach for the nano/micrometre scale patterning of both inorganic and organic thin films, such as self-assembled monolayers [1]. Patterned hard silicon oxide was employed as a hard template and water-induced bridge formation is attributed to the origin of the observed adhesive contact force between the substrates and the templates during the pattern transfer. Non-contacted areas were served as growth sites for thin layers of various metal oxides by using ALD. CAL is a simple and universal method to form hard oxide thin film patterns without incorporation of resistive layers, and should have potential for applications in micro/nano electronics, optoelectronics, flexible electronics, biochips, and complex nanostructure fabrication.