| 摘要 |
PROBLEM TO BE SOLVED: To obtain a small-sized element by confining elastic wave energy in the inside of a substrate. SOLUTION: A substrate wherein a metal electrode 3, a dielectric thin film 4 and another dielectric thin film 5 are adhered on a piezoelectric substrate 1, and the substrate can confine elastic wave energy therein. Especially, by using a SiO<SB>2</SB>thin film as a thin film 4 and an AIN thin film as a thin film 5, the substrate having a high electromechanical coupling coefficient (k<SP>2)</SP>and superior frequency-temperature characteristics is obtained by making the film thickness of electrodes 3 and those of the thin film 4 and the thin film 5 optimum. COPYRIGHT: (C)2009,JPO&INPIT
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