Intrinsically switchable thin film ferroelectric resonators utilizing electric field induced piezoelectric effect

This paper presents bulk acoustic wave resonators using the ferroelectric materials barium titanate and barium strontium titanate. The electric field induced piezoelectric effect in these materials is utilized in the design of various types of intrinsically switchable bulk acoustic wave resonators. Both thickness mode and lateral mode resonator results, which have been demonstrated recently, are summarized in this paper. Significantly improved quality factors by means of forming a ferroelectric-on-silicon structure are also demonstrated.