Single crystal piezoelectric RF resonators and filters with improved cavity definition
US10630259B2 · kind B2 · utility
Assignee
Inventor
Key dates
| Filing date | Feb 5, 2018 |
| Grant date | Apr 21, 2020 |
| Priority date | — |
| Expiry date | Jul 12, 2038 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03H2003/021
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
An FBAR filter device comprising an array of resonators, each resonator comprising a single crystal piezoelectric layer sandwiched between a first and a second metal electrode,wherein the first electrode is supported by a support membrane over an air cavity, the air cavity being embedded in a silicon dioxide layer over a silicon handle, with through-silicon via holes through the silicon handle and into the air cavity, the side walls of said air cavity in the silicon dioxide layer being defined by barriers of a material that is resistant to silicon oxide etchants, and wherein the interface between the support membrane and the first electrode is smooth and flat.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.