Structure and manufacturing method of surface acoustic wave filter with back electrode of piezoelectric layer
US12088271B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Sep 16, 2022 |
| Grant date | Sep 10, 2024 |
| Priority date | — |
| Expiry date | Mar 9, 2043 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03H2003/021
- WIPO fieldSurface technology, coating
- WIPO sectorChemistry
Abstract
A fabrication method of a surface acoustic wave (SAW) filter includes obtaining a piezoelectric substrate, forming a back electrode on a first portion of the piezoelectric substrate, forming a first dielectric layer on the first portion of the piezoelectric substrate, forming a trench in the first dielectric layer, forming a second dielectric layer on the first dielectric layer formed with the trench, forming a third dielectric layer on the second dielectric layer, removing a second portion of the piezoelectric substrate to obtain a piezoelectric layer, forming an interdigital transducer (IDT) on the piezoelectric layer, and etching and releasing a portion of the first dielectric layer surrounded by the trench to form a cavity below the back electrode.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.