PURPOSE: to increase the conversion efficiency of a surfce acoustic waves SAW, by forming an electrode of face-centered cubic structure on a piezoelectric film of wurtzite structure with C axis orientation on a substrate, and forming the piezoelectric film of wurtzite structure on it through C axis orientation.
CONSTITUTION: A piezoelectric thin film 11 of wurtzite structure such as ZnO, AlN is constituted on a glass substrate 10 with sputtering, and the C axis is oriented almost toward vertical direction as the plane of the substrate 10. The metallic film is formed by vacuum depostion of centered-face cubic structure such as Al and Au on the thin film 11, and the surface acoustic wave electrode is constituted by photoetching this metallic film into a prescribed shape. The piezoelectric material of wurtzite structure such as AlN and ZnO is sputtered on the thin film 11 and the electrode 12 to form a piezoelectric thin film 13. Even on the plane of ZnO, and on the plane of Al, the C axis of the thin film 13 is made easy to be oriented toward vertical direction to the substrate 10, the difference of the slope of orientation of the thin film 13 on the thin film 11 and the electrode 12 is decreased, allowing to increase the conversion efficiency of the surface acoustic waves.
| WO/2023/100670 | FILTER DEVICE |
| JP4901398 | Surface acoustic wave device |
| JP2000091871 | ENVELOPE AND SURFACE ACOUSTIC WAVE DEVICE |
ANDOU KENJI
YAMAGAMI ATSUSHI
