A study of capacitance-voltage curve narrowing effect in capacitive microelectromechanical switches

In this letter, we report on the capacitance-voltage (C-V) curve narrowing effect, which occurs in the oxide-based microelectromechanical switches that are subjected to dc bias stress for a prolonged period of time. The narrowing effect for the noncontact dc bias stress condition is shown, which proves that membrane-to-dielectric contact is not needed for narrowing to occur. It is also shown that neither mechanical degradation nor charge trapping due to dielectric conduction or air ionization is solely responsible for the C-V instabilities reported in the literature.