Electromechanical modeling of silicon nanowire switches: size and boundary condition effects

Abstract

Understanding the operational behavior of nanoelectromechanical systems (NEMS) is the preliminary step to design functional sensors and actuators. Miniaturization is considered for further improvement in sensitivity, while the extreme surface area in NEMS devices plays a leading role in the effective performance through size dependence physical properties. Nanowire (NW) switches are one such device with significant surface effects present on the pull-in voltage. This study introduces a new approach to implement the surface effect into electromechanical behavior of NW switches based on finite element analysis. The influence of size and boundary condition on pull-in voltage is studied for silicon NWs. Results demonstrate the importance of length-to-thickness ratio as a suitable parameter to express the surface effect rather than the surface-area-to-volume ratio.