| 摘要 |
PROBLEM TO BE SOLVED: To provide a thin film piezoelectric element which has good characteristics and is small-sized and has a low production cost by integrating a wide-band filter or a resonator having a wide oscillation frequency range with a semiconductor circuit. SOLUTION: A dielectric layer 4 is provided on a semiconductor substrate 1, and a foundation conductor layer 5 is provided on the dielectric layer 4, and a piezoelectric ceramic thin film 27 is provided on the foundation conductor layer, and a conductive electrode pattern 6 is provided on the piezoelectric ceramic thin film 27, and they are so constituted that kh<=2 or d/h<=0.1 is true where h, a, and k are the thickness of the piezoelectric ceramic thin film 27, the thickness of the foundation conductor layer 5, and the coefficient of the surface wave propagated in the direction parallel with the surface of the piezoelectric ceramic thin film 27 respectively. |
