Transversely-excited film bulk acoustic resonator fabrication using polysilicon pillars
US12075700B2 · kind B2 · utility
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Key dates
| Filing date | Dec 3, 2021 |
| Grant date | Aug 27, 2024 |
| Priority date | — |
| Expiry date | Sep 27, 2042 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03H2003/023
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
An acoustic resonator device is formed using sacrificial polysilicon pillar by forming a polysilicon pillar on a substrate and depositing a dielectric layer to bury the polysilicon pillar and planarizing the surface of the dielectric layer. A piezoelectric plate is bonded to the planarized surface of the dielectric layer and thinned to a target piezoelectric membrane thickness. At least one conductor pattern is formed on the thinned piezoelectric plate and the polysilicon pillar is then removed using an etchant introduced through holes in the piezoelectric plate to form an air cavity where the pillar was removed.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.