Acoustic wave device and radio-frequency front-end circuit
US11509284B2 · kind B2 · utility
Assignee
Inventor
Key dates
| Filing date | Jun 11, 2019 |
| Grant date | Nov 22, 2022 |
| Priority date | — |
| Expiry date | Jul 10, 2041 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03H9/02834
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
An acoustic wave device includes a piezoelectric layer, an IDT electrode, a high-acoustic-velocity support substrate, and a low-acoustic-velocity film. The high-acoustic-velocity support substrate is located on an opposite side of the piezoelectric layer from the IDT electrode in the thickness direction of the piezoelectric layer. The low-acoustic-velocity film is disposed between the high-acoustic-velocity support substrate and the piezoelectric layer in the thickness direction. The high-acoustic-velocity support substrate includes a base region and a surface region disposed nearer to the low-acoustic-velocity film than the base region in the thickness direction and whose crystal quality is worse than that of the base region. The surface region includes first and second layers disposed nearer to the base region than the first layer in the thickness direction and whose crystal quality is better than that of the first layer.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.