BAW resonators based on aluminum nitride thin films

Author

Dubois, Marc-Alexandre ; Muralt, Paul ; Plessky, Victor

Author_Institution

Dept. of Mater., Swiss Fed. Inst. of Technol., Lausanne, Switzerland

Volume

2

fYear

1999

fDate

1999

Firstpage

907

Abstract

The fabrication and the characterization of solidly mounted (SMR) and membrane-based (TFBAR) bulk acoustic wave resonators made of piezoelectric aluminum nitride (AlN) thin films are presented. The resonance frequencies are 2.4 and 3.5 GHz, respectively. The active λ/2 AlN thin films were grown on Pt electrode layers by pulsed dc reactive magnetron sputtering. Simulation calculations were performed to fit experimental admittance curves. For both resonator types, a sound velocity of 11350 m/s was derived, which corresponds to a c₃₃ ^D of 420 GPa. The devices typically exhibited figures of merit Q·k_t² of 6 to 16. A zero thermal frequency drift was obtained in the TFBAR structure due to a SiO₂ layer as compensating element

Keywords

acoustic resonators; aluminium compounds; bulk acoustic wave devices; piezoelectric thin films; sputtered coatings; 2.4 GHz; 3.5 GHz; AlN; BAW resonator; Pt electrode; SiO₂ compensating element; admittance; aluminum nitride; fabrication; figure of merit; membrane; numerical simulation; piezoelectric thin film; pulsed DC reactive magnetron sputtering; resonance frequency; solidly mounted resonator; sound velocity; thermal frequency drift; thin film bulk acoustic wave resonator; Acoustic waves; Aluminum nitride; Electrodes; Fabrication; Film bulk acoustic resonators; Piezoelectric films; Resonance; Resonant frequency; Sputtering; Transistors;

fLanguage

English

Publisher

ieee

Conference_Titel

Ultrasonics Symposium, 1999. Proceedings. 1999 IEEE

Conference_Location

Caesars Tahoe, NV

ISSN

1051-0117

Print_ISBN

0-7803-5722-1

Type

conf

DOI

10.1109/ULTSYM.1999.849136

Filename

849136