Design and analysis of a cantilever-based MEMS switch with dielectric thin film material coatings for enhanced electrostatic actuation

Abstract

Abstract The selection of an appropriate dielectric material for a microelectromechanical systems (MEMS)-based radio-frequency cantilever switch is essential for achieving reliable operation, improved actuation performance, rapid response, and stable thermal behavior. In this work, a rectangular cantilever structure is designed at a micro scale. It optimized the influence of dielectric materials on response time, operating capacitance between the beam and electrodes, and thermal performance. During operation at elevated pull-in voltages, excess heat may be generated, leading to dielectric degradation and potential short-circuit failure. Therefore, understanding the thermal characteristics of the device is important for reliable performance. To mitigate dielectric breakdown, thermally stable and sensitive dielectric layers are employed to maintain effective operation under varying temperature conditions. COMSOL Multiphysics tool utilized for designed and analysis of Radio frequency MEMS switch properties. Different dielectric materials (Al 2 O 3 , La 2 O 3 , TiO 2 , SiO 2 , and HfO 2 ) are coated on the electrodes, forming a dielectric barrier that prevents short circuits when the device is in the ON state while ensuring stable actuation. The actuation behaviour is evaluated by applying voltages ranging from 1 V to 15.1 V, generating the electrostatic force required for beam deflection. The results indicate that optimal performance is achieved with a longer beam length, smaller width and thickness. Among the investigated materials, HfO 2 exhibits the best overall performance, achieving the fastest response within the temperature range of 10–40 °C, a capacitance of 0.122 pF, and a pull-in voltage of 9.1 V corresponding to the maximum displacement.