Elastic wave device

Abstract

An elastic wave device includes a piezoelectric substrate mainly including lithium niobate, an interdigital transducer electrode provided on the piezoelectric substrate, and a dielectric film, provided on the piezoelectric substrate and covering the interdigital transducer electrode, and mainly including silicon oxide. The elastic wave device uses a Rayleigh wave. The interdigital transducer electrode includes main electrode layers that include one or more first main electrode layer made of a metal with a C112/C12 ratio greater than the C112/C12 ratio of the silicon oxide with regard to the elastic constants C11 and C12. The sum of the thicknesses of the one or more first main electrode layers is about 55% or more based on the thickness of the whole interdigital transducer electrode is about 100%.

Dependencies are inferred from the claim text.