Fabrication method of micromachined quartz glass resonator using sacrificial supporting structures

In this study, a novel fabrication method of quartz glass resonators is proposed. The resonators are mechanically supported by Au posts, which are also used as bonding material between the quartz glass device layer and the substrate. The mechanical supporting structures consist of anchor structures and sacrificial supporting structures. The anchor structures remain to support the fabricated resonators during operation while the sacrificial supporting structures are removed during the release process of the resonator. The sacrificial supporting structures were employed to mechanically support the fragile resonator structure during the whole fabrication process. The supporting structures also played a role to dissipate the generated heat during the plasma process and keep the device layer temperature low. Using the proposed method, micromachined resonators were successfully fabricated on a quartz glass substrate. The maximum process temperature was less than 400 degrees C, thus the method has a large potential as a mean to fabricate quartz glass microstructures on various kind of substrates including the complimentary metal-oxide semiconductor (CMOS) substrates. (C) 2020 Elsevier B.V. All rights reserved.