Piezoelectric aluminum nitride resonator for oscillator

Olivier Mareschal (1) , S. Loiseau (2, 3) , A. Fougerat (2) , L. Valbin (4) , G. Lissorques (4) , Sébastien Saez (1) , Christophe Dolabdjian (1) , R. Bouregba (3) , G. Poullain (3)

1 Equipe Electronique - Laboratoire GREYC - UMR6072
2 NXP Semiconductors
3 CRISMAT - Laboratoire de cristallographie et sciences des matériaux
4 ESYCOM - Electronique, Systèmes de communication et Microsystèmes

This work investigates properties of the thin film elongation acoustic resonator (TFEAR) operating at MHz frequencies in air. This resonator is composed of a piezoelectric layer of aluminum nitride (AlN) sandwiched between two aluminum electrodes (Al). TFEAR works in the extensional mode excited via AlN d31 piezoelectric coefficient. A 3D-finite element method analysis (FEM) using ANSYSreg software has been performed to model static modal and harmonic behavior of the TFEAR. In order to consider insertion losses into the substrate, equivalent electrical models based on modified Butterworth-Van Dyke (MBVD) circuit have been improved by adding extra dissipative elements. Thus, a whole model for the on-wafer characterization set-up is given, allowing for automatic de-embedding of the present TFEAR equivalent circuit. Quality factor Q as high as 2500 in air have been recorded with motional resistance lower than 400 Omega. A first oscillator based on a TFEAR resonator was also designed and tested.

Domaines: Sciences de l'ingénieur [physics]; Electromagnétisme

Olivier Mareschal, S. Loiseau, A. Fougerat, L. Valbin, G. Lissorques, et al.. Piezoelectric aluminum nitride resonator for oscillator. Frequency Control Symposium, 2009 Joint with the 22nd European Frequency and Time forum. IEEE International, Apr 2009, Besançon, France. p894-897. ⟨hal-00994757⟩