Bulk acoustic wave resonator and fabrication method thereof
US11689171B2 · kind B2 · utility
Assignee
Inventor
Key dates
| Filing date | Nov 18, 2022 |
| Grant date | Jun 27, 2023 |
| Priority date | — |
| Expiry date | Nov 18, 2042 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03H2003/021
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
A fabrication method of a bulk acoustic wave (BAW) resonator includes: sequentially forming a buffer layer, a piezoelectric layer, and a first electrode on a temporary substrate; forming a first dielectric layer on the piezoelectric layer and covering the first electrode; forming a trench in the first dielectric layer; forming a second dielectric layer on the first dielectric layer and in the trench; forming a third dielectric layer on the second dielectric layer and filling in the trench; forming a bonding layer on the third dielectric layer; bonding a resonator substrate to the third dielectric layer via the bonding layer; removing the temporary substrate and the buffer layer to expose a surface layer of the piezoelectric layer; removing the surface layer of the piezoelectric layer; forming a second electrode on the piezoelectric layer; and removing a portion of the first dielectric layer surrounded by the trench to form a cavity.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.