Thin film resonators fabricated on membranes created by front side releasing
US6355498B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Aug 11, 2000 |
| Grant date | Mar 12, 2002 |
| Priority date | — |
| Expiry date | Aug 11, 2020 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03H2003/021
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
A new bulk resonator may be fabricated by a process that is readily incorporated in the traditional fabrication techniques used in the fabrication of monolithic integrated circuits on a wafer. The resonator is decoupled from the wafer by a cavity etched under the resonator using selective etching through front openings (vias) in a resonator membrane. In a typical structure the resonator is formed over a silicon wafer by first forming a first electrode, coating a piezoelectric layer over both the electrode and the wafer surface and forming a second electrode opposite the first on the surface of the piezoelectric layer. After this structure is complete, a number of vias are etched in the piezoelectric layer exposing the surface under the piezoelectric layer to a selective etching process that selectively attacks the surface below the piezoelectric layer creating a cavity under the resonator.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.