Composite ferroelectric fbars that are switchable between the first and second harmonics: experimental demonstration

Author

Vorobiev, Andrei ; Gevorgian, Spartak

Author_Institution

Dept. of Microtechnol. & Nanosci., Chalmers Univ. of Technol., Gothenburg, Sweden

Volume

62

Issue

3

fYear

2015

fDate

42064

Firstpage

565

Lastpage

575

Abstract

Digital switching between the first and second harmonics, in a composite thin-film bulk acoustic wave resonator (FBAR), is demonstrated experimentally. The FBAR consists of two 180-nm-thick paraelectric-phase Ba_0.25Sr_0.75TiO₃ films separated by a 50-nm-thick SrRuO₃ conducting layer. The resonant frequency of this composite resonator (with Pt bottom and Al top electrodes) is switched from 3.6 GHz to 7.6 GHz, where the polarity of the 5 V dc bias is reversed on one of the ferroelectric films. The frequency switching ratio (f₂/f₁ ≥ 2) depends on the thickness of the electrodes. Some adjustment of f₂/f₁ is possible by changing the applied dc bias.

Keywords

acoustic resonators; barium compounds; bulk acoustic wave devices; conducting materials; ferroelectric devices; ferroelectric thin films; strontium compounds; thin film devices; Ba_0.25Sr_0.75TiO₃; SrRuO₃; composite ferroelectric FBARs; composite thin-film bulk acoustic wave resonator; conducting layer; dc bias polarity; digital switching; electrodes; ferroelectric films; first harmonics; frequency 3.6 GHz to 7.6 GHz; frequency switching ratio; paraelectric-phase films; resonant frequency; second harmonics; size 180 nm; size 50 nm; voltage 5 V; Electrodes; Film bulk acoustic resonators; Frequency measurement; Harmonic analysis; Q-factor; Resonant frequency; Switches;

fLanguage

English

Journal_Title

Ultrasonics, Ferroelectrics, and Frequency Control, IEEE Transactions on

Publisher

ieee

ISSN

0885-3010

Type

jour

DOI

10.1109/TUFFC.2014.006501

Filename

7055450