SURFACE ACOUSTIC-WAVE SUBSTRATE AND ACOUSTIC-WAVE SUBSTRATE USING ULTRA-LOW SPEED THIN-FILM, AND SURFACE ACOUSTIC-WAVE FUNCTION ELEMENT AND ACOUSTIC-WAVE FUNCTION ELEMENT USING THE SUBSTRATE

摘要

PROBLEM TO BE SOLVED: To provide a surface acoustic-wave function element and an acoustic-wave function element having a small propagation loss, being small-sized and having a high performance.;SOLUTION: Reed screen-shaped electrode metallic thin-films 7 and 8 are attached on a piezoelectric substrate 1, and an ultra-low speed thin-film being composed of a grating structure and having a propagation speed of 1,000 m/s or less or a TeO₂ thin-film 9 is attached on the electrode metallic thin-films 7 and 8. Accordingly, the surface acoustic-wave function element having an extremely thin film thickness and a large reflection coefficient is obtained. A dispersion type function element having a structure attaching the ultra-low speed thin-film or the TeO₂ thin-film on the surface of the piezoelectric substrate or a piezoelectric thin-film substrate is acquired as a constitution. Alternately, a surface acoustic-wave substrate employing the thin-film as the grating structure and having the large reflection coefficient or the acoustic-wave function element using an acoustic-wave resonator combining the thin-film and a high-impedance thin-film is further obtained as the constitution.;COPYRIGHT: (C)2008,JPO&INPIT