Power Mems Development
Abstract
In Task 1.1, we were able to fabricate two silicon-on-insulator (SOI) wafers and two double-side-polished (DSP) wafers. The fabricated wafers were bonded and then released and tested for circuit breaker configuration. The first bonded wafer pair failed during the deep reactive-ion etching (DRIE) release step due to insufficient masking material. This bonded wafer pair was processed in SRI's MicroSystems Engineering Laboratory in Menlo Park, CA (MSELWest), where the selectivity of etching silicon to silicon oxide is lower due to variations in the process resulting from equipment set differences. The second bonded wafer pair, which was processed in MSEL-East (Largo, FL), released as expected. During testing we observed that a few cantilevers acted as circuit breakers; however, we were not able to obtain resettable circuit breakers. We will present a detailed analysis of the test results in next month's report. In Task 1.2, we simultaneously processed three versions of wafers. Wafers processed in Task 1.1 also contained voltage multiplier switches. During testing of the resettable circuit breaker switches, we found that the cantilevers actuate and perform as breakers as we indicated by the circuit resistance changing from 10 Momega to 200 omega following actuation at 19 V. More testing on those devices is currently in progress. In the second version, an additional mask was designed to etch the bulk silicon under the MEMS plate to keep the plate from moving toward the substrate. Wafers processed in this version failed during the structure silicon etch step. In MSEL-West, the 4-in. wafer is mounted on a 6-in. wafer for DRIE. During this step the resist that was in place to protect the structure got burned due to overheating in the etch process, and the springs connecting the plates to the anchor were etched away. Finally, we developed a new method of processing, involving fewer tools and faster turnaround, using two of the Version 1 masks.
Document Details
- Document Type
- Technical Report
- Publication Date
- Feb 01, 2011
- Accession Number
- ADA538106
Entities
People
- Drew Hanser
- John Bumgarner
Organizations
- SRI International