| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide an air bridge type FBAR exhibiting excellent resonance characteristics (high orientation and densification) in which local stress to a piezoelectric film is relaxed, a stabilized structure causing no damage or breakage of the piezoelectric film is realized, productivity is enhanced by increasing the yield and the cost is reduced, and to provide its fabrication process. <P>SOLUTION: The thin film bulk acoustic resonator comprises a substrate 10; a supporting layer 11 formed on the substrate 10 in convex shape, and a multilayered body of a lower electrode 12; a piezoelectric film 13; and an upper electrode 14 formed on the substrate 10 and the supporting layer 11 in a region including an air gap V above the supporting layer 11 wherein the air gap V is formed between the supporting layer 11 and the lower electrode 12 such that at least a part thereof is located above the surface of the supporting layer 11 and constitutes a resonance region. The supporting layer 11 has a height not less than 20% of the maximum height from the surface of the supporting layer 11 to the top of the air gap V. <P>COPYRIGHT: (C)2005,JPO&NCIPI |
