Bulk acoustic wave resonator, bulk acoustic wave filter, RF module including bulk acoustic wave resonator and/or filter, and bulk acoustic wave oscillator
US7586390B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Feb 2, 2006 |
| Grant date | Sep 8, 2009 |
| Priority date | — |
| Expiry date | Nov 4, 2026 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03H9/175
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
A bulk acoustic wave resonator which has excellent elasticity and high electromechanical energy conversion efficiency. A bulk acoustic wave resonator comprises a substrate, a lower electrode formed on the substrate, an interlayer formed on the lower electrode layer, a piezoelectric layer formed on the interlayer, and an upper electrode layer formed on the piezoelectric layer. Moreover, both the first lattice mismatch, which is determined between a short edge of the lattice constituting a closest packed plane of a material consisting of an interlayer and a short edge of the lattice constituting a closest packed plane of a material consisting of a piezoelectric layer, and the second lattice mismatch, which is determined between a long edge of the lattice constituting a closest packed plane of a material consisting of an interlayer and a long edge of the lattice constituting a closest packed plane of a material consisting of the piezoelectric layer, are 7% or less, and a lower electrode layer is a material in which the value of the elastic stiffness C33 is 300 GN/m2 or more.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.