Events: Details
Understanding and Improving Longevity In RF MEMS Capacitive Switches
| Category: | Seminar |
|---|---|
| Description: | Dr. Chuck Goldsmith, Ph.D., MEMtronics Corporation. Capacitive switching technology possesses many benefits over both conventional electronic switching devices and ohmic-contact MEMS switches at microwave and millimeter-wave frequencies. These benefits include a very high figure of merit, low effective on-resistance, reliable hot-switched operation, miniscule power consumption, and ultra-high linearity. To date, the lifetime limiting mechanism within capacitive switching has been dielectric charging of the switch insulator. This has limited the cycle lifetimes and continuous "on" operation of these switches. Recent advancements in our understanding of dielectric charging are paving the way to improved device operation. Developments in electronic characterization have demonstrated that transient current spectroscopy can be effectively used to characterize the charging phenomenon within MEMS capacitive switches. Using the appropriate charge models, relevant characteristics of the charged carriers can be extracted, including such important characteristics as carrier lifetimes and densities as a function of voltage and temperature. This improved understanding of the charging phenomena enables improved switch designs which reduce the amount of dielectric charging and ensure sufficient restoring force to overcome stiction due to charging. Strategies for improving capacitive switch lifetime include 1) reducing operating bias voltages, 2) incorporating electrical designs which trade capacitance ratio for lifetime (typically achieved through a change in the dielectric to air ratio), and 3) innovative materials development. This presentation overviews the challenges, successes, and failures associated with the quest to improve capacitive RF MEMS switch lifetime. Data featuring lifetime demonstrations over 100 billion cycles will be included. |
| When: |
Monday 18 May 2009, 10:30 AM - 11:30 AM (EST) |
| Where: | Birck 1001, Purdue University |