Wafer-level vacuum-encapsulated silicon resonators with arc-welded electrodes

George Xereas; Vamsy P. Chodavarapu

Wafer-level vacuum-encapsulated silicon resonators with arc-welded electrodes

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Author(s): George Xereas¹ and Vamsy P. Chodavarapu²
- Affiliations: 1: Department of Electrical and Computer Engineering , McGill University , Montreal, Quebec H3A0E9 , Canada ;
  2: Department of Electrical and Computer Engineering, Kettering Laboratories , University of Dayton , Dayton, OH 45469 , USA
Source: Volume 13, Issue 1, January 2018, p. 54 – 57
DOI: 10.1049/mnl.2017.0270 , Online ISSN 1750-0443

Received 16/05/2017, Accepted 31/07/2017, Revised 20/07/2017, Published 01/01/2018

This work presents wafer-level vacuum-encapsulated silicon resonators that utilise movable electrodes and arc welding in order to achieve deep sub-micron transduction gaps. The devices are fabricated using micro-electro-mechanical systems (MEMS) integrated design for inertial sensors (MIDIS) process, a commercial pure-play MEMS process, offered by Teledyne DALSA Semiconductor Inc.. The default minimum transduction gap in the MIDIS process is 1.5 μm. Here, the work introduces a technique to permanently reduce the transduction gap of the resonator using localised arc welding to a designed width of ∼200 nm. The prototype Lamé mode resonators are encapsulated in an ultra-clean 10 mTorr vacuum cavity that ensures long-term stability. The quality factor was measured to be 1.37 million at a resonance frequency of 6.89 MHz. With the narrower gap, the motional resistance of the resonators is reduced by a factor of ten times.

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Wafer-level vacuum-encapsulated silicon resonators with arc-welded electrodes

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