Performance Analysis of Nano-Electro-Mechanical-System Ultrasonic Sensor with Fringing Field Effects

In this work, modeling of the fringing field effects in a silicon carbide (SiC) based micromachined ultrasonic transducer (MUT) is reported. For such a micro/nano dimensional structure, the edge effect (fringing field) extends far away and plays an important role in overall device operation. This extended field enhances the device equivalent capacitance. The analytically developed model is validated by finite element method (FEM). Electrostatic force developed and the actuated membrane displacement profiles are also evaluated in this work. The study involves Landau and Lifschitz method for evaluating equivalent device capacitance for establishing the fringing effect in the SiC MUT. Three dimensional modelling is also exhibited here to accurately portray the device characteristics precisely. Both the analytical and simulation establish the significant effect of fringing field in device operation.