Deep reactive ion etching (DRIE) is investigated as a tool for the realization of nanostructures and architectures, including nanopillars, silicon nanowires or carbon nanotubes on Si nanopillars, nanowalls, and nanonetworks. The potential of combining top-down fabrication methods with the bottom-up synthesis of one-dimensional nanocomponents is assessed. The field-emission properties of carbon nanotubes/Si pillars hybrid structures are measured, as well as the transport properties of large-area nanowires obtained via nanowire lithography. The potential of DRIE for the fabrication of three-dimensional nanostructures is also revealed.