| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide an acoustic resonator structure for inhibiting lateral mode vibration as unnecessary vibration, and to provide an electric filter using the acoustic resonator structure. <P>SOLUTION: As for a thin-film bulk acoustic resonator(FBAR) as a kind of piezoelectric resonator, the resonator 200 has a lower electrode 207, a piezoelectric element 206, and an upper electrode 201, which are laminated sequentially on a cavity 208 formed on a substrate 205. The lower electrode 207 and the upper electrode 201 have substantially equal profile and dimensions. An action region of the resonator 200 is demarcated by an overlapped area of the lower electrode 207 and the upper electrode 201. In this structure, a frame element 204, which brings mismatching of acoustic impedance between the upper electrode 201 and an upper connection portion 203, is located at an interface between the upper electrode 201 and the upper connection portion 203. <P>COPYRIGHT: (C)2009,JPO&INPIT</p> |
