Herein, the unzipping and translocation of DNA duplexes through a sub-2 nm silicon nitride (SiN) solid-state nanopore have been demonstrated by well-resolved three-level blockades. In order to examine our observations, we applied a simple model which is applicable to the unzipping and translocation processes of DNA duplexes through solid-state nanopores. The generation of these highly recognizable signatures is an important step towards the real applications of solid-state nanopores in complex samples.