| 摘要 |
PURPOSE:To facilitate impedance matching with an external circuit by forming two partial electrodes in the position corresponding to the place where an insulating thin film is not formed through piezoelectric films. CONSTITUTION:On a substrate 21 of silicon, crystal, etc., having a hole 22 by etching, a conductive thin film 31 is formed, an insulating thin film 32 is formed on the conductive film 31, and the insulating thin film 32 is etched away at a part corresponding to the hole 22. Then, a piezoelectric thin film 24 and partial electrodes 26 and 27 are formed. Since parts of the film 32 corresponding to the electrodes 26 and 27 are conductive, energizing electric terminals led out of the partial electrodes 26 and 27 electrically causes such oscillation that when the overlap part between the electrode 26 and conductive film 31 extends in the thickness direction, the overlap between the electrode 27 and conductive thin film 31 contracts. |
