Substrate processing and membrane release of transversely-excited film bulk acoustic resonator using a sacrificial tub
US12119805B2 · kind B2 · utility
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Key dates
| Filing date | Dec 10, 2021 |
| Grant date | Oct 15, 2024 |
| Priority date | — |
| Expiry date | Apr 13, 2043 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03H2003/0442
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
An acoustic resonator device is formed using a sacrificial layer and a front side etched cavity by forming a recess in a silicon substrate with a trap-rich top layer and filling the recess with sacrificial silicon nitride. A bonding oxide (BOX) layer is formed over the trap-rich layer and the sacrificial silicon nitride filled recess and a piezoelectric plate is bonded to the BOX layer. The sacrificial silicon nitride is then removed to form a cavity by using an etchant introduced through holes in the piezoelectric plate and BOX layer without removing the BOX layer from over the cavity.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.