Method to control BAW resonator top electrode edge during patterning
US7612488B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Jan 16, 2007 |
| Grant date | Nov 3, 2009 |
| Priority date | — |
| Expiry date | Aug 23, 2027 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T29/49156
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
A piezoelectric resonator include a multi-layer top electrode. The multi-layer top electrode includes at least a top metal layer and a bottom metal layer. A top metal layer edge is recessed compared to a bottom metal layer edge allowing conformal deposition of a passivation layer. The passivation layer covers and protects the underlying layers from subsequent etching, thereby preventing etch undercut of the top electrode. In some embodiments, the multi-layer top electrode is configured as a bi-layer. In other embodiments, an extra layer is configured between the top metal layer and the bottom metal layer, for example a shunt load layer.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.