Microstructuring of cobalt (Co) thin films by UV laser irradiation.

This work reports the microstructuring of cobalt (Co) thin films by high-energy UV pulsed laser irradiation. The parameters responsible for the efficient formation of such microstructures include laser fluence and film parameters. Cracks and island formations were observed for Co thin films deposited by RF sputtering. Such rough films rendered to produce inefficient microstructuring. To overcome this limitation, Co thin films were deposited by vacuum evaporation resulting in a smooth thin film compatible for laser-induced microstructuring. Two stages of conical patterning are discussed in terms of localized melting and abrupt condensation of the melted Co film owing to laser irradiation. An efficiency of 90% for laser-based microstructuring suggests that it is an efficient and non-invasive technique for fabricating nanostructures. [ABSTRACT FROM AUTHOR]