Abstract:
A method for fabricating an air-gap type FBAR, an FBAR fabricated thereby, and a filter and a duplexer using an FBAR are provided to form simply an air gap without a CMP process, and a process for removing a sacrificial layer by laminating an LCP thin film on a silicon substrate having a cavity part. A first substrate(200) includes a cavity part formed on a predetermined region of an upper surface thereof. A dielectric layer(220) is formed on the first substrate(200) in order to form a first air gap(210) on the cavity part of the first substrate(200). A stacked resonance part(230) is formed by laminating a bottom electrode/piezoelectric layer/top electrode on the dielectric layer(220). A second substrate(240) includes a cavity part formed on a predetermined region of a bottom surface thereof.