Fabrication of 2D polymer nanochannels by sidewall lithography and hot embossing

A novel method for fabricating two-dimensional (2D) polymer nanochannels by combining the sidewall lithography technique with the hot embossing approach is presented in this paper. A layer of nano-thick Au film was first sputtered on the surface of the micro-sized photoresist mesas. Then, arrays of one-dimensional (1D) Au nano-sidewalls were formed by anisotropic sputter etching. By taking the 1D Au nano-sidewalls as a mask, the 2D silicon nano-mold was obtained by deep reactive ion etching. The patterns of the 2D nano-mold were replicated directly into a 1 mm thick polyethylene terephthalate substrate by using the hot embossing technique. Polymer nanochannel arrays with dimensions of about 100 nm in width, 100 nm in depth and 4 mm in length fabricated uniformly over a large area were obtained. The resolution of nano-mold patterns fabricated in our work is not limited by ultraviolet optical lithography but by the thickness of the Au film deposited onto the photoresist mesas. The proposed method provides a low-cost way to produce high-quality and high-throughput 2D polymer nanochannels.