Using metal-insulator-semiconductor capacitor to investigate the charge accumulation in capacitive RF MEMS switches

A metal-insulator-semiconductor (MIS) capacitor is used to simulate the metal-insulator-metal (MIM) structure of capacitive RF MEMS switches. By measuring the C-V characteristics for the MIS structure, the dielectric charging in capacitive RF MEMS switches can be analyzed. An analytical model has been established to describe the feasibility of this method. In the experiment, the effect of the constant voltage stress on the charge accumulation in the dielectric layer of MIS capacitor was investigated. The experimental results show that three main physical processes dominate the dielectric charging behavior. The advantages of using this method are that the reliability test of the switches and the evaluation of the candidate dielectric materials can be carried out by using MIS capacitor, the experimental cost, therefore, can be sharply reduced.