Thermal oxidation as a simple method to increase resolution in nanoimprint lithography

We introduce a simple thermal oxidation technique for decreasing feature sizes of nanoimprint lithography (NIL) masters. During oxidation, the dimensions of negative features are reduced (e.g., gaps become narrower), and the dimensions of positive features increase (e.g., lines become wider). We demonstrate that positive feature sizes can also be reduced after oxidation by selective etching of the oxide. We show that 74 nm gaps can be reduced to 10 nm and 226 nm lines can be narrowed to 55 nm. The reduction in feature size achieved in both positive and negative structures directly translates into increased imprint resolution, and we demonstrate improved resolution in a complete NIL pattern transfer using thermally oxidized NIL masters.

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