CPC H03H 9/547 (2013.01) [H03H 3/04 (2013.01); H03H 9/02228 (2013.01); H03H 9/02559 (2013.01); H03H 9/132 (2013.01)] | 19 Claims |
1. An acoustic resonator comprising:
a substrate;
a piezoelectric layer attached to the substrate either directly or via one or more intermediate layers; and
an interdigital transducer (IDT) at the piezoelectric layer and having a plurality of interleaved fingers that each comprise a first layer adjacent the piezoelectric layer and a second layer over the first layer,
wherein the first layer has a top surface that extends at a first angle relative to the surface of the piezoelectric layer, and the second layer has a sidewall that extends at a second angle relative to the surface of the piezoelectric layer,
wherein the second angle is greater than the first angle, and
wherein a thickness of the first layer is less than a thickness of the second layer, with the respective thicknesses being measured in a direction substantially orthogonal to the surface of the piezoelectric layer.
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