Bulk acoustic wave resonator and manufacturing method thereof, filter using the same, semiconductor integrated circuit device using the same, and high frequency module using the same
US7221242B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Feb 28, 2005 |
| Grant date | May 22, 2007 |
| Priority date | — |
| Expiry date | Mar 26, 2025 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03H9/706
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
A bulk acoustic wave resonator in which the problem of the technology for forming the diaphragm structure is resolved, which is more compact and improved the frequency accuracy, and the manufacturing method thereof, a filter using the same, a semiconductor integrated circuit device using the same, and a high frequency module using the same are provided. The bulk acoustic wave resonator according to the present invention comprises a substrate having a first surface and a second surface opposite to the first surface, and a staked resonator including a first electrode film in contact with the first surface, a piezoelectric film overlaying the first electrode film and a second electrode film overlaying the piezoelectric film. The substrate is provided with an air gap including a first aperture opening at the first surface and a second aperture opening at the second surface at the position corresponding to the staked resonator, respectively and having air gap generally vertical shape to the first surface, and another air gap having a tapered shape in the vicinity of the first surface.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.