Method of producing thin-film bulk acoustic wave devices
US6548943B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Apr 12, 2001 |
| Grant date | Apr 15, 2003 |
| Priority date | — |
| Expiry date | Jul 13, 2021 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03H3/02
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
A method of producing a BAW device with reduced spurious resonance, wherein the device comprises a top electrode, a bottom electrode and a piezoelectric layer therebetween. A frame-like structure is formed on top of the top electrode for suppressing the spurious resonances. The frame-like structure is produced in a self-aligning fashion in that the frame-like structure is used to define the top electrode area. Furthermore, it is preferred that the frame-like structure is made of a different material from the top electrode. The frame-like structure is caused to fuse with the contacting part of the top electrode to form an alloy. An etching mask is then used to cover at least part of the frame-like structure and the entire top electrode surrounded by the frame-like structure for etching. An etching medium is used to remove the unreacted portion of the top electrode outside the frame-like structure.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.