Micromachined thin film bulk acoustic resonators

Author

Ruby, R. ; Merchant, P.

Author_Institution

Hewlett-Packard Labs., Palo Alto, CA, USA

fYear

1994

fDate

1-3 Jun 1994

Firstpage

135

Lastpage

138

Abstract

We have fabricated thin film bulk acoustic resonators (FBARS) with measured Q´s of over 1000 and resonant frequencies as low as 1.5 GHz and as high as 7.5 GHz. The device, as currently fabricated, consists of the piezoelectric material aluminum nitride (AlN) sandwiched between electrodes all of which lie on a thin low-stress silicon nitride (Si_xN_y) membrane. Integrated on the membrane are small microheaters for frequency tuning and/or temperature stabilization. We have observed frequency shifts of 50 to 80 ppm per degree C depending on relative material thicknesses. Maximum temperature excursions over 580 C could be achieved using the microheaters. We have also observed frequency shifts of 5 to 10 ppm per volt depending on harmonic

Keywords

Q-factor; acoustic microwave devices; acoustic resonators; aluminium compounds; bulk acoustic wave devices; membranes; micromachining; micromechanical resonators; silicon compounds; thin film devices; tuning; 1.5 GHz; 580 C; 7.5 GHz; AlN; SiN; frequency shifts; frequency tuning; microheaters; micromachined thin film bulk acoustic resonators; piezoelectric material; relative material thicknesses; resonant frequencies; temperature stabilization; thin low-stress Si_xN_y membrane; Acoustic devices; Acoustic measurements; Biomembranes; Film bulk acoustic resonators; Frequency measurement; Piezoelectric films; Piezoelectric materials; Resonant frequency; Temperature; Transistors;

fLanguage

English

Publisher

ieee

Conference_Titel

Frequency Control Symposium, 1994. 48th., Proceedings of the 1994 IEEE International

Conference_Location

Boston, MA

Print_ISBN

0-7803-1945-1

Type

conf

DOI

10.1109/FREQ.1994.398344

Filename

398344