A predictive contact reliability model for MEM logic switches

Micro-electro-mechanical (MEM) switches are of interest for ultra-low-power electronics applications [1-5] because they offer the ideal characteristics of zero off-state leakage and abrupt switching behavior. The endurance of these devices can be limited by Joule heating at the contacting asperities (Figs. 1 and 2) which eventually leads to welding-induced failure. To provide guidance for reliable MEM switch design, a predictive contact reliability model is developed and validated in this work. The results show that device endurance depends not only on the contact material, but also on the operating voltage, series resistance, load capacitance, and logic style. Using the reliability model, endurance exceeding 10¹⁵ on/off cycles is projected for a scaled MEM switch technology operating at 1V.