BAW filters having different center frequencies on a single substrate and a method for providing same
US6518860B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jan 5, 2001 |
| Grant date | Feb 11, 2003 |
| Priority date | — |
| Expiry date | Jan 5, 2021 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T29/42
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
A method of fabricating a plurality of bulk acoustic wave (BAW) resonators on a single substrate, and the corresponding product, the BAW resonators having substantially different resonant frequencies, the method including the steps of: providing a substrate having an upper facing surface; depositing an isolation structure on the upper facing surface of the substrate; depositing a first metallic layer on the isolation structure, the first metallic layer serving as a bottom electrode; and depositing piezolayer material on the bottom electrode so as to have thicknesses corresponding to each of the different resonant frequencies, each different thickness located in a location where a resonator having a resonant frequency corresponding to the thickness is to be located. In one of several embodiments, the step of depositing piezolayer material on the bottom electrode itself includes the steps of: depositing piezolayer material to a thickness corresponding to the lowest frequency resonator; providing hard mask material over areas where the lowest frequency resonators are to be located; and removing the piezolayer material down to the thickness of the next higher frequency resonators. In s…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.