Actuation Voltage For a Cantilever Switch in MEMS

Preamble

Following the successful 3D simulation of the process flow of cantilever based MEMS switches using VICTORY Process is presented in August 2005 Simulation Standard article “Process Flow Simulation and Manufacture”, a novel analytical method to predict the actuation voltage for such switches is presented here. This will help extend the utility of the process simulation to the prediction of the required voltage needed for cantilever switches and the circuit design required to drive such switches.

1. Introduction

When a system of conductors is charged, or subjected to some external electric potentials, the charge will entirely reside on the surfaces of the conductors and will distribute itself on each closed surface such as to make that surface equipotential and the field inside the conductor material zero. The charge on each surface will interact with itself and with other charges, which will result in net forces on each surface element. The net force on each surface element is normal to the surface, and given by the formula