Transversely-excited film bulk acoustic resonator with multiple diaphragm thicknesses and fabrication method
US11201601B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Aug 7, 2020 |
| Grant date | Dec 14, 2021 |
| Priority date | — |
| Expiry date | Aug 7, 2040 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03H2003/0435
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
Filter devices and methods are disclosed. A filter device includes a substrate having a surface. A back surface of a single-crystal piezoelectric plate is attached to the surface of the substrate, portions of the single-crystal piezoelectric plate forming a plurality of diaphragms spanning respective cavities in the substrate. A conductor pattern is formed on a front surface of the piezoelectric plate, the conductor pattern including a plurality of interdigital transducers (IDTs) of a plurality of resonators. Interleaved fingers of at least a first IDT of the plurality of IDTs are disposed on a diaphragm having a first thickness, and interleaved fingers of at least a second IDT of the plurality of IDTs are disposed on a diaphragm having a second thickness less than the first thickness.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.