Lithography-free fabrication of single crystalline silicon tubular nanostructures on large area

► We develop facile fabrication for single crystalline Si tubular nanostructures. ► Thin metal film is thermally dewetted to form nanodots for etch mask in Si RIE. ► Redeposition of metal from nanodot during RIE produces metal rim around nanodot. ► Etch rate difference between Si and nanodot/rim results in tubular nanostructure. ► Lithography-free and large-area fabrication of tubular nanostructure is proposed.