On the dispersive behaviour of AlN/Si High Overtone Bulk Acoustic Resonators

Harmonic Bulk Acoustic Resonators are build on a SOI to allow for a good spectral separation of the device resonance. SOI is etched back to allow for the fabrication of well defined resonance in the vicinity of 2.45 GHz. Thermal sensitivity close to -25 ppm/K also was measured. The analysis of experimental data obtained for resonance taking place in the whole stack allows for emphasizing a dispersive behavior of the harmonic modes of the structure.