| 摘要 |
PROBLEM TO BE SOLVED: To manufacture a piezoelectric resonator whose temperature characteristic of resonance frequency is stable, resonance response is large and resonance characteristic is excellent. SOLUTION: A SiO1 thin film 23 is formed on the upper surface of a Si board 22, the SiO1 thin film 23 is formed on a cavity 24 provided by opening the middle part of Si board 22. A piezoelectric layered body 28 composed of a AlN piezoelectric thin film 26A and a ZnO piezoelectric thin film 26Z on the SiO1 thin film is formed. Driven electrodes 27b, 27a are provided at the upper and lower surfaces of the piezoelectric layered body 28. The sign of the temperature coefficient of resonance frequency between the ZnO piezoelectric thin film 26Z and the AlN piezoelectric thin film 26A is reverse, so thst they are offset and totally the temperature coefficient becomes zero. As ZnO and AlN are piezoelectric materials, resonance characteristic is improved.
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