SURFACE ACOUSTIC WAVE RESONATOR WITH SUPPRESSED TRANSVERSE MODES USING SELECTIVE DIELECTRIC REMOVAL

摘要

Aspects of this disclosure relate to a surface acoustic wave resonator that may include a piezoelectric substrate, interdigital transducer (IDT) electrodes disposed on an upper surface of the piezoelectric substrate, and a dielectric film covering the piezoelectric substrate and the IDT electrode for temperature compensation. The IDT electrodes may include bus bar electrode regions spaced apart from each other in a transverse direction perpendicular to a propagation direction of a surface acoustic wave to be excited, an overlapping region sandwiched between the bus bar regions, and gap regions defined between respective bus bar electrode regions and the overlapping region in the transverse direction. Each of the gap regions may include a dummy electrode in a dummy electrode region extending from the bus bar electrode region in the transverse direction. The dielectric film may include an open region exposing a respective bus bar electrode region and dummy electrode region.