| 摘要 |
PURPOSE:To attain inexpensively and easily a high frequency device with high efficiency by using a surface wave substrate of three-layer structure and utilizing a Rayleigh wave on the substrate of surface wave. CONSTITUTION:A dielectric substrate 1 is made of an inexpensive borosilicate glass from which a mirror face is obtained easily, a thin film of aluminum oxide (Al2O3) is formed by the RF sputtering and further an interdigital transducer 3 comprising comb-tooth electrodes is formed on the film 2. Then a piezoelectric thin film 4 made of zinc oxide (ZnO) is formed by the sputtering so as to form a three-layer structure of ZnO/Al2O3/ glass, the film thickness h2 of the ZnO thin film 4 is taken as 0.3<=h2/lambda<=1.0 and the film thickness h1 of the Al2O3 thin film 2 is taken as 0.1<=h1/lambda<=10. |
