Improvement of hot switching lifetime in MEMS DC switches using a drain voltage-sustaining capacitor

Reliability in hot switching operations of MEMS DC switches is enhanced by introducing a drain voltage-sustaining capacitor, which leads to electric field-less or arc-less switching operations. The role of the capacitor is to eliminate the electric potential difference between the suspended beam and the drain electrode at the switch “opening” instant. In the case of a pure Au-Au contact, we have experimentally demonstrated that the lifetime of conventional MEMS switches with the suggested method was improved dramatically, by an order of magnitude, in the relatively high electric-field hot switching condition. We clearly observed material transfer at failure in the device without the capacitor, whereas stiction was the main failure mechanism in the device with the capacitor. Owing to the simplicity of the proposed method, it can be adopted in any type of MEMS DC switches in order to greatly enhance the switch lifetime.