Influence of Femtosecond Laser Parameters on Fabrication of Photomask by Direct Ablation
P. Stanley, K. Venkatakrishan, L.E.N. Lim and B.K.A. Ngoi
Photomask is an important prerequisite for the fabrication of microdevices. Currently it is fabricated by lithography, which is a complex, multistep process, and hence time consuming. In order to address these issues, a single step technique has been developed for the fabrication of photomask by femtosecond laser ablation. The femtosecond laser parameters affecting the fabrication of photomask are pulse energy, number of pulses and the scanning resolution of the scanning system. In this work, the influence of these parameters for improving the edge quality and size of the photomask feature has been studied in detail. By controlling these parameters sub-micron feature size has been achieved. Also a detailed discussion has been carried out on the use of femtosecond laser system with high repetition rate, for further reducing the feature size of the photomask.