Nano-Patterns of Photoresist Fabricated by Ultraviolet Lithography Technology

Nanofluidics devices with two-dimensional nano-structures have attracted extensive interests for biological and chemical applications. The fabrication of nanoscale mask patterns with controllable line width is an indispensable process for manufacturing two-dimensional nano-structures. However, a simple and low-cost method for fabricating two-dimensional nano-patterns is still a challenge. In this work, a novel simple and low-cost method for fabricating nanoscale mask patterns with controllable line width, based on the ultraviolet exposure is presented. In the experiment, a layer of AZ5214 reversal photoresist was exposed to the ultraviolet light through the photomask with microscale patterns. After the lithography, nanoscale photoresist mesas patterns instead of microscale patterns were produced. The photoresist mesas with 400~800 nm width were fabricated. Meanwhile, by adjusting the parameters of exposure time, various nanoscale dimensions of photoresist mesas can be obtained. The proposed method overcomes limitations of the conventional ultraviolet lithography technology without the need to the expensive nanolithography equipment. Our novel fabrication method should be a useful tool for two-dimensional nano-structures fabrication due to its advantages of simple fabrication process, well controllability, and low-cost.