Nanoelectromechanical torsion switch of low operation voltage for nonvolatile memory application

Nanoelectromechanical torsion switches are fabricated by using focused ion beam milling on silicon-on-insulator substrate. The device layer thickness of the substrate is 220 nm. A 9 μm long and 1.5 μm wide suspended silicon cantilever is mechanically connected to peripheral silicon device layer via a silicon torsion spring with the length of 2.4 μm and width of 530 nm. After hydrofluoric-acid vapor releasing, the silicon cantilever shows downward deflection. The pull-in voltage is about 5.5 V and the ratio of current measured at the ON/OFF states is over 1000. Moreover, the simulated data of pull-in voltage of torsion switch is in agreement with the experimental result, which will contribute to design of an optimal nanoelectromechanical torsion switch with a driven voltage as low as 1.2 V. According to the preliminary results, this torsion switch with low driven voltage has a great potential for high density non-volatile memory application.