Direct Measurement of Field Emission Current in E-static MEMS Structures

Direct experimental evidence of field emission currents in metallic MEMS devices is presented. For the first time, high resolution I-V curves has been demonstrated for microgaps in MEMS-based capacitor/switch-like geometries. The I-V dependence shows a good agreement with a Fowler-Nordheim theory, supporting the hypothesis that field emission plays a significant role in charging phenomena in MEMS switches. The data has been used to extract effective values of the field enhancement factor, beta, for the metallic structures fabricated under typical MEMS processes.