Stochastic MEMS sensor using white noise oscillation for high temperature environment - Design based on physical model and its verification by device prototype-

This paper describes a stochastic MEMS sensor, which will be used in low S/N environments like in high temperature plants. A mass which vibrates between two counter electrodes by white voltage noise is "pulled in" to either of the electrodes by the application of pulse voltage to the mass. The direction of the pull-in is determined stochastically, and the probability that the mass is "pulled in" to a particular side depends on mechanical strain applied to the sensor structure. The behavior of the stochastic MEMS sensor was simulated using a developed simulator based on a physical model. The stochastic MEMS sensor was prototyped on an SOI wafer and the probability was measured as a function of the bias voltage. This experimental result was compared with the simulated result. Both results agree well, confirming the validity of the developed simulator and the physical model.