Patent ID: 8487720

Claim:
An acoustic wave resonator comprising: a piezoelectric substrate having an upper surface; an interdigital transducer (IDT) electrode that includes a first comb-shaped electrode provided on the upper surface of the piezoelectric substrate and a second comb-shaped electrode provided on the upper surface of the piezoelectric substrate, the second comb-shaped electrode interdigitating with the first comb-shaped electrode; and a dielectric film that is provided on the upper surface of the piezoelectric substrate to cover the IDT electrode, wherein the first comb-shaped electrode includes: a first busbar provided on the upper surface of the piezoelectric substrate to extend in a first direction; and a plurality of first electrode fingers that are provided on the upper surface of the piezoelectric substrate and that extend from the first busbar in a second direction non-perpendicular to the first direction, the second comb-shaped electrode includes: a second busbar provided on the upper surface of the piezoelectric substrate to extend in the first direction; and a plurality of second electrode fingers that are provided on the upper surface of the piezoelectric substrate and that extend from the second busbar in a third direction opposite to the second direction, the plurality of second electrode fingers interdigitating with the plurality of first electrode fingers at an interdigitating region, and a surface of the dielectric film inclines with respect to the upper surface of the piezoelectric substrate at an edge of the dielectric film.