Superhydrophobic surfaces fabricated by nanoimprint lithography

Superhydrophobic surfaces were fabricated on silicon by nanoimprint lithography and wet chemical etching. Glass molds were used to imprint a positive photoresist layer. The residual layer in imprinted regions was removed by UV-ozone exposure and subsequent developing of the photoresist. The pattern is transferred to a thin SiO2 layer by buffered hydrofluoric acid etching and then to Si by isotropic hydrofluoric-nitric-acetic acid (HNA) or by anisotropic KOH etching. After coating the samples with a hydrophobic self-assembled monolayer of octadecyltriclorosilane contact angles of water drops were measured and compared to model predictions.