Abstract: The present disclosure provides a film bulk acoustic resonator and its fabrication method. The film bulk acoustic resonator includes a first substrate, a support layer bonded on the first substrate, a first cavity formed in the support layer, a piezoelectric stacked layer on the support layer, a first trench and a second trench which are formed in the piezoelectric stacked layer, a dielectric layer over the piezoelectric stacked layer, a second cavity formed in the dielectric layer, and a second substrate covering the second cavity, where the first trench is connected to the first cavity, and the second trench is connected to the second cavity.

Abstract: The present disclosure provides a film bulk acoustic resonator and its fabrication method. The film bulk acoustic resonator includes a first substrate, a first support layer containing a first cavity, a piezoelectric stacked layer, and a first separation structure and/or a second separation structure. The piezoelectric stacked layer includes an effective working region and a parasitic working region; and in the parasitic working region, a first electrode and a second electrode have a corresponding region along a thickness direction. The first separation structure separates the first electrode, and the first electrode of a portion of the parasitic working region is insulated from the first electrode of the effective working region; and the second separation structure separates the second electrode, and the second electrode of a portion of the parasitic working region is insulated from the second electrode of the effective working region.

Abstract: The present disclosure provides a film bulk acoustic resonator and its fabrication method, a filter, and a radio frequency communication system. The film bulk acoustic resonator includes a first substrate and a support layer disposed on the first substrate, where a cavity is formed in the support layer; a piezoelectric stacked layer covering the cavity, where the piezoelectric stacked layer includes an active resonance region and an inactive resonance region surrounding the active resonance region; and at least two trenches, arranged at a junction of the active resonance region and the inactive resonance region to define a range of the active resonance region. The at least two trenches include a first trench and a second trench; the second trench passes through the second electrode layer and the piezoelectric layer; and the first trench passes the first electrode and the piezoelectric layer and is connected to the cavity.

Abstract: The present disclosure provides a film bulk acoustic resonator and its fabrication method. The film bulk acoustic resonator includes a first substrate, a support layer bonded on the first substrate, a first cavity formed in the support layer, a piezoelectric stacked layer on the support layer, a first trench and a second trench which are formed in the piezoelectric stacked layer, a dielectric layer over the piezoelectric stacked layer, a second cavity formed in the dielectric layer, and a second substrate covering the second cavity, where the first trench is connected to the first cavity, and the second trench is connected to the second cavity.

Abstract: The present disclosure provides a film bulk acoustic resonator and its fabrication method. The film bulk acoustic resonator includes a first substrate, a first support layer containing a first cavity, a piezoelectric stacked layer, and a first separation structure and/or a second separation structure. The piezoelectric stacked layer includes an effective working region and a parasitic working region; and in the parasitic working region, a first electrode and a second electrode have a corresponding region along a thickness direction. The first separation structure separates the first electrode, and the first electrode of a portion of the parasitic working region is insulated from the first electrode of the effective working region; and the second separation structure separates the second electrode, and the second electrode of a portion of the parasitic working region is insulated from the second electrode of the effective working region.