| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide an FBAR wherein stable manufacturing which does not cause breakage or teardown of a piezoelectric film is realized, and improvement of productivity and low cost by increase of yield are realized, and further superior resonance characteristic (high orientation and densification of the piezoelectric film) is obtained in an air bridge structured type FBAR. <P>SOLUTION: The FBAR is provided with a substrate 10; a supporting layer 20 which is formed on the substrate 10 except an air gap V region; and a lamination which is formed on the substrate 10 in a region including the air gap V and constituted of a lower electrode 11, the piezoelectric film 12, and an upper electrode 13. The air gap V is formed between the substrate 10 and the lower electrode 11 so that at least a part is positioned above the surface of the substrate 10 and constitutes a resonance region. Alternatively, at a step-difference portion corresponding to shape of an end of the air gap, the interface of the piezoelectric film and the lower electrode has configuration, e.g. wherein a plurality of surfaces which are not parallel to the surface of the substrate and whose angles with the surface of the substrate are different from each other are stacked from a substrate side to the tip side of the air gap. <P>COPYRIGHT: (C)2005,JPO&NCIPI |
