Reversible electrostatic control of micromechanical structure tunneling characteristics

Abstract

We report on a submicrometer thick, surface nanomachined curvature-free metallic cantilever with an insulated contact tip applied as a micromechanical contact tunneling device. A technique for modulating the tunneling current characteristics based on an elastic compressible contact surface model is demonstrated by changing the effective tunneling area for asperities via change in electrostatic pressure. The electrostatic pressure comes from the excess potential applied on the gate after the cantilever has been switched on. This allows the gate voltage to independently modulate the characteristics of the tunneling barrier that the electrons must cross in a reversible manner. Preliminary measurements show a reasonably good agreement with the Hertzian contact force law.