| 摘要 |
PURPOSE:To form excellently an electrode on a piezoelectric thin film by applying taper so that an end of the piezoelectric thin film has a specific tilt angle or below to a face of a substrate. CONSTITUTION:SiO2 films 2, 3 are formed to both sides of an Si substrate 1, the center of the film 3 is removed in a form of a square, a recessed part 4 is formed reaching the film 2 by using films 2, 3 as masks, an electrode 5 is formed on a substrate film 2a by a metallic film, a ZnO piezoelectric thin film is formed on it and a piezoelectric thin film 6 is formed with etching. In this case, a taper is applied so that the tilt angle theta of the edge of the thin film 6 to a face of the substrate 1 is <=60 deg.. Finally, an electrode 7 is formed on the piezoelectric thin film 6 in a direction orthogonal to the electrode 5. Parts of both the electrodes 5, 7 are opposed while clipping the thin film 6. In applying an electric signal between both the electrodes, since the composite film comprising the films 2 and 6 is oscillated in longitudinal thickness oscillation, a resonator is formed. Thus, the metallic film is deposited excellently at the edge of the piezoelectric thin film 6 and the rate of opened electrode 7 is improved remarkably. |
