Degradation Mechanisms of Contact Point During Switching Operation of MEMS Switch

A micro electro mechanical system (MEMS) switch is one of the most promising MEMS applications. It is almost the ideal switching device with superior performance in comparison to conventional semiconductor switching devices. The remaining issue is its short lifetime due to the failure of the contact. Therefore, we examine degradation mechanisms at the mechanical contact point in the MEMS switch by operating it in the transmission electron microscope for real-time observation. Material transfer, delamination, destruction, and bridge formation at a gold contact point are in-situ visualized during the contact and separation process of the MEMS switch. Although gold is a favorable material in terms of low contact resistance, our results suggest that the contact material should be hard and have a high melting point for long lifetime.