| abstract |
A electromechanical coupling coefficient k t 2 and Q values are both large, and the thickness control of the lower electrode to provide easy FBAR and a manufacturing method thereof. A substrate 11; a lower electrode 14 that is mechanically held in a part of the substrate 11 in a hollow state; and includes all of the lower electrode 14 within a region occupied by the self on a planar pattern. In addition, the piezoelectric body 15 disposed on the lower electrode 14; the upper electrode 16 on the piezoelectric body 15; between the substrate 11 and the piezoelectric body 15, located on the boundary of the region occupied by the piezoelectric body 15 on the planar pattern. And a relay electrode 13 connected to the lower electrode 14 in the occupied region; and a lower electrode wiring 17 connected to the relay electrode 13 extending to the outside from the boundary of the occupied region. [Selection] Figure 3 |