Piezoelectric bulk layers with tilted c-axis orientation and methods for making the same
US11381212B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Mar 20, 2019 |
| Grant date | Jul 5, 2022 |
| Priority date | — |
| Expiry date | Jun 28, 2039 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03H9/54
- WIPO fieldSurface technology, coating
- WIPO sectorChemistry
Abstract
Bulk acoustic wave resonator structures include a bulk layer with inclined c-axis hexagonal crystal structure piezoelectric material supported by a substrate. The bulk layer may be prepared without first depositing a seed layer on the substrate. The bulk material layer has a c-axis tilt of about 32 degrees or greater. The bulk material layer may exhibit a ratio of shear coupling to longitudinal coupling of 1.25 or greater during excitation. A method for preparing a crystalline bulk layer having a c-axis tilt includes depositing a bulk material layer directly onto a substrate at an off-normal incidence. The deposition conditions may include a pressure of less than 5 mTorr and a deposition angle of about 35 degrees to about 85 degrees.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.