Fabrication of nano-patterns of photoresist by ultraviolet lithography and oxygen plasma

Nanofluidic devices with two-dimensional nanochannels have many applications in biology and chemistry, however, it is still a challenge to develop a low-cost and simple method for fabricating nano-masks that can be used to produce two-dimensional nanochannels. In this paper, a novel low-cost and simple method, based on UV lithography and oxygen plasma, was proposed to fabricate nano-mask. The influence of exposure time on the photoresist mesas was investigated in the ultraviolet lithography process. The parameters of RF power and treatment time on the width reduction of photoresist mesas were analyzed by the oxygen plasma. In our work, in order to increase the efficiency controllability of photoresist removal, a RF power of 90 W, a pressure of oxygen plasma 60 Pa, and the time division method were adopted to remove photoresist by oxygen plasma. Finally, nano-patterns of photoresist mesas with bottom width of 330 nm were successfully fabricated. The proposed method provides a low-cost way to produce high-throughput two-dimensional nanochannels.