Controlled batch fabrication of crystalline silicon nanobeam-based resonant structures

This work presents a self-controlled nano-precision top-down fabrication technique for batch fabrication of single crystalline silicon nanobeams and incorporation of such in electromechanical devices and systems. The fabrication technique takes advantage of the crystalline structure of silicon for the ultimate self-alignment and self-control leading to extremely smooth sidewalls, sharp corners, and controllable feature size reduction. Nanobeams with well uniform width as small as ~250 nm are fabricated on thin SOI substrates utilizing only conventional optical lithography with 2 μm resolution and anisotropic wet etching of silicon. Thermally actuated resonators using such nanobeams as thermal actuators/piezoresistive sensors have been successfully fabricated and characterized.