The objective of this award is to develop electrodes with enhanced reliability for microelectromechanical systems (MEMS) ohmic contact switches. Gold is commonly used as the electrode material because of its high ductility, low electrical resistivity, inertness to oxidation, high thermal conductivity, and relatively high melting point. However, the reliability of gold electrodes must be improved for many intended applications. Electrodes in this study will benefit from the high electrical and thermal conductivity of an underlying gold film, but their surfaces will be engineered through the deposition of nanoscale coatings or the creation of nanoscale morphological features. The influence of the length scale of these surface modifications on the performance of the electrodes will be studied to refine the electrode design. These surface modifications are expected to mitigate failures caused by electrodes sticking together, arcing and material transfer, and increasing contact resistance with use. This investigation is coupled with materials characterization of new, cycled, and failed switches provided by collaborators from industry and government laboratories, including switches that will incorporate the electrodes developed in this study.
MEMS ohmic contact switches offer many advantages over solid-state switches for electronic circuits. Advantages include lower power consumption, lower insertion losses, better isolation, and higher linearity. Circuits with these switches are therefore attractive for wireless communication, wireless sensors, aerospace applications, and military and commercial radar systems. The proposed work will lead to enhanced reliability of switches for these applications. It will also further knowledge in the field of electromechanical properties of nanoscale materials and their surfaces. The thesis research of a graduate student will be supported, and undergraduate senior thesis students will participate. An activity on the fabrication, electromechanical properties, and use of thin films in microelectromechanical systems will be developed for a summer camp that draws participants from high schools across the nation.
