Method of making an acoustic wave resonator with mass loading strip for suppression of hyperbolic mode

A method of manufacturing a surface acoustic wave resonator, the method comprising:

• forming or providing a surface acoustic wave resonator structure with a temperature compensation layer over an interdigital transducer electrode, the interdigital transducer electrode positioned on a piezoelectric layer and extending along a first length, the interdigital transducer electrode including one or more fingers extending from a bus bar to an edge portion;
• and
• forming a mass loading strip that overlaps with the edge portion of the one or more fingers, the mass loading strip including a layer having a density that is at least as high as a density of a material of the interdigital transducer electrode that is in contact with the piezoelectric layer, the mass loading strip extending from a proximal end to a distal end along a second length shorter than the first length to thereby suppress a hyperbolic mode of the interdigital transducer electrode