Acoustic wave resonator, filter, and multiplexer
US10938371B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Apr 20, 2018 |
| Grant date | Mar 2, 2021 |
| Priority date | — |
| Expiry date | Aug 29, 2039 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH10N30/87
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
An acoustic wave resonator includes: an IDT located on a piezoelectric substrate, including comb-shaped electrodes facing each other and including electrode fingers and a bus bar connecting the electrode fingers; a first silicon oxide film located on the electrode fingers in an overlap region where the electrode fingers overlap and having a film thickness in a part of edge regions, which correspond to both ends of the overlap region, equal to or less than that in a center region sandwiched between the edge regions; and a second silicon oxide film located on the electrode fingers, containing an element slowing an acoustic velocity in a silicon oxide film when being added to the silicon oxide film, having a concentration of the element greater than that in the first silicon oxide film, and having a film thickness in a part of the edge regions greater than that in the center region.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.