| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a BAW resonance device that can improve crystallinity of piezoelectric layers and mechanical quality factors of entire resonators, can be ruggedized, and can prevent the erosion of the piezoelectric layers caused by etchant in formation of cavities, and to provide a method of manufacturing the same. <P>SOLUTION: A lower electrode 31 of the resonator 3, which includes the piezoelectric layer 32 comprising a PZT thin film, and the cavity 1a, which exposes a surface at the side of a support substrate 1 in an insulating layer 4, are formed on the support substrate 1, and an etching hole 5 communicating with the cavity 1a is formed in the insulating layer 4. The support substrate 1 is composed of an upper-layer substrate 11 comprising a single-crystal MgO substrate and a lower-layer substrate 12 comprising a single-crystal Si substrate. The cavity 1a is composed of an opening 11a formed by wet anisotropy etching utilizing the crystal orientation dependence of etching speed to the upper-layer substrate 11 from both the surface sides in a thickness direction of the upper-layer substrate 11, and a through-hole 12a that penetrates in a thickness direction of the lower-layer substrate 12 and communicates with the opening 11a. <P>COPYRIGHT: (C)2010,JPO&INPIT |
