Film bulk acoustic resonator fabrication method
US11146238B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Aug 7, 2020 |
| Grant date | Oct 12, 2021 |
| Priority date | — |
| Expiry date | Aug 7, 2040 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03H2003/0442
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
Methods of fabricating acoustic resonators are disclosed. A back surface of a piezoelectric plate is bonded to a surface of a substrate. Thickness measurements are made at a plurality of positions on the piezoelectric plate. Excess material is removed from the front surface of the piezoelectric plate in accordance with the thickness measurements to improve a thickness uniformity of the piezoelectric plate. A conductor pattern is formed on the front surface, the conductor pattern including a plurality of interdigital transducers (IDTs) of a plurality of resonators. Cavities are formed in the substrate such that portions of the single-crystal piezoelectric plate form a plurality of diaphragms spanning respective cavities, wherein interleaved fingers of each IDT of the plurality of IDTs are disposed on a respective one of the plurality of diaphragms.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.