Patent ID: 6842089
Filing Date: 2005-01-11
Classification: H03H,Y10T

Abstract:
1. A film bulk acoustic resonator (FBAR) device, which is applied to a ladder type filter comprising a plurality of series resonators and a plurality of shunt resonators, said FBAR comprising: a substrate; an insulating layer formed on the substrate; a membrane support layer being formed on the insulating layer and comprising a plurality of air-gaps; a membrane layer being formed on the membrane support layer and comprising a plurality of active regions to correspond to the air-gaps; a plurality of lower electrodes, each being formed on the active region; a plurality of piezoelectric layers, each being formed on the lower electrode; and a plurality of upper electrodes, each being formed on the piezoelectric layer, wherein a thickness of the active region corresponding to the series resonator differs from a thickness of the active region corresponding to the shunt resonator.