Methodology to analyze failure mechanisms of ohmic contacts on MEMS switches

This paper demonstrates the efficiency of a new methodology using a commercial nanoindenter coupling with electrical measurement on test vehicles specially designed to investigate the micro contact reliability. This study examines the response of gold contacts with 5 mum² square bumps under various levels of current flowing through contact asperities. Contact temperature rising is observed leading to shifts of the mechanical properties of contact material, modifications of the contact topology and a diminution of the time dependence creep effect. The data provides a better understanding of micro-scale contact physics especially failure mechanisms due to the heating of the contact on MEMS switches.