Surface acoustic wave device including an IDT formed by a metal filled in grooves on a piezoelectric substrate

摘要

A surface acoustic wave device includes a LiNbO3 substrate and is constructed such that the reflection coefficient of an IDT is not only high but the electromechanical coupling coefficient K2 is also high, and the range of Euler angles of the LiNbO3 substrate can be increased to realize a wide range of the electromechanical coupling coefficient K2. A plurality of grooves are provided in an upper surface of the LiNbO3 substrate, an IDT including a plurality of electrode fingers is provided by filling a metal material in the plurality of grooves, and the metal material is Pt or W or an alloy primarily including at least one Pt or W.