Facile large-area photolithography of periodic sub-micron structures using a self-formed polymer mask

This letter reports the methodology of a low-cost fabrication technique for producing periodic sub-micron structures over a large area, using a polymer mask. A thin film of gold/palladium or silica is deposited on a stretched polydimethylsiloxane (PDMS) substrate. Release of the tension forms a buckling sinusoidal pattern on the surface. The PDMS substrates are then used as masks in soft contact optical lithography, bypassing the need for an expensive lithographic process toward creating regular patterns on a traditional masks. Pattern transfers are conducted using an ultraviolet lamp and the fabrication of more complex periodic structures through multiple exposures is reported.