Facile fabrication of sub-20-nm nanochannels based on crystallinity-dependent anisotropic etching of silicon

► We utilized the anisotropic wet etching of silicon to fabricate nanochannels. ► Nanochannels were formed in silicon wafer by single step of microscale lithography. ► The massively parallel and wafer scale nanochannel fabrication was easily achieved. ► No nanolithography or complicated processes were introduced. ► The minimum feature size was 16 nm in depth and 175 nm in width.