The disclosed technology relates to an acoustic wave device including a piezoelectric layer with localized regions having atoms implanted therein, and an electrode over the piezoelectric layer, where the acoustic wave device is configured to generate an acoustic wave.

Aspects of this disclosure relate to bulk acoustic wave devices that include an acoustic reflector, a frame structure over the acoustic reflector, electrodes including a first electrode and a second electrode, and a piezoelectric layer having a surface facing the acoustic reflector that is flat (a) over an entirety of the active region and (b) beyond the first electrode over the acoustic reflector, The first electrode and the second electrode overlap and are on opposing sides of the piezoelectric layer in the active region. The first electrode is positioned between the piezoelectric layer and the acoustic reflector in the active region. Related acoustic wave filters, multiplexers, radio frequency modules, radio frequency systems, wireless communication devices, methods of manufacture, and methods of filtering are disclosed.

Aspects of this disclosure relate to a bulk acoustic wave device having a main acoustically active region and a frame region. The bulk acoustic wave device can include a first electrode, a second electrode spaced apart from the first electrode in a first direction, a frame structure in the frame region, a piezoelectric layer positioned between the first electrode and the second electrode in at least the main acoustically active region, and a dielectric layer in at least part of the frame region such that the piezoelectric layer is positioned between portions of the dielectric layer in a second direction different from the first direction. The dielectric layer can include a different material than the piezoelectric layer.

The present disclosure provides a resonator and a preparation method therefor, relating to the technical field of resonators. The resonator comprises a substrate, and a first electrode layer, a first piezoelectric layer, and a second electrode layer which are sequentially stacked onto the substrate. The first electrode layer, the first piezoelectric layer, and the second electrode layer form a first overlapping region along the stacking direction. A capacitor stacking layer is arranged on the first piezoelectric layer and located outside the first overlapping region. A passivation layer is arranged above the second electrode layer, and the passivation layer extends above the capacitor stacking layer.