Intrinsically switchable contour mode acoustic wave resonators based on barium titanate thin films

This paper summarizes the design, fabrication, and performance of an intrinsically switchable contour mode acoustic wave resonator using the ferroelectric material barium titanate (BaTiO₃ or BTO). The resonance frequency of contour mode resonators is mainly determined by its lateral dimensions. Because of the electrostrictive effect in BTO thin films, the acoustic resonance can be turned on by the application of a DC bias voltage. The BTO contour mode resonator has series and parallel resonance frequencies of 159.7 MHz and 160.45 MHz, respectively, when biased at 12 V. The quality factors for the series and parallel resonance frequencies are 47 and 83, respectively.