Surface acoustic wave element

摘要

A highly reliable surface acoustic wave device includes a low-resistance piezoelectric substrate that is difficult to reoxidize even in a high-temperature atmosphere containing oxygen. The piezoelectric substrate has a specific resistance of about 1.0x10⁷ Omega.cm to about 1.0x10¹³ Omega.cm, an interdigital electrode on a main surface of the substrate, and a protective film covering the interdigital electrode.