Lifetime Testing of a Developmental MEMS Switch Incorporating Au/MWCNT Composite Contacts

摘要

Microelectromechanical systems (MEMS) have many advantages including: low power operation and small size. Compared with competitive technologies (such as PIN diodes and FETs) metal-contacting MEMS switches exhibit low onresistance, good isolation and excellent high frequency performance, making them attractive for RF applications, e.g. telecommunications. The lifetime of metal-contacting MEMS switches is limited due to electrical and mechanical interactions between the contacting surfaces. Contact degradation results in an increase in contact resistance and ultimately device failure. A potential solution to significantly increase device lifetime is to use Au/MWCNT composites for one or more of the electrical contacts. The compliance of the composite renders a larger contact area, and dissipates the impact energy from the contact force more effectively. In previous work, the advantages of Au/MWCNT composites for switching applications have been described. In this work we discuss the first implementation of a MEMS device utilising the Au/MWCNT composite technology. As well as demonstrating an application of the Au/MWCNT composite technology, the MEMS device serves as a platform which has been used to further investigate the failure mechanisms. The results are compared to an established methodology. A discussion on the effect of the effect of low contact forces (typical within MEMS) is given.