Transversely-excited film bulk acoustic resonator with etch-stop layer
US10911023B2 · kind B2 · utility
Assignee
Inventor
Key dates
| Filing date | Jul 20, 2020 |
| Grant date | Feb 2, 2021 |
| Priority date | — |
| Expiry date | Jul 20, 2040 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH10N30/877
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
Acoustic resonator devices and methods are disclosed. An acoustic resonator device includes a substrate having a surface and a single-crystal piezoelectric plate having front and back surfaces. An aluminum oxide etch-stop layer is sandwiched between the surface of the substrate and the back surface of the piezoelectric plate, a portion of the piezoelectric plate and the etch-stop layer forming a diaphragm spanning a cavity in the substrate. An interdigital transducer (IDT) is formed on the front surface of the single-crystal piezoelectric plate with interleaved fingers of the IDT disposed on the diaphragm. The aluminum oxide etch-stop layer is impervious to an etch process used to form the cavity.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.