Piezoelectric film bulk acoustic resonator

A piezoelectric film bulk acoustic resonator comprising:

• a substrate;
• a bottom electrode;
• a piezoelectric layer;
• a top electrode;
• an etching insertion layer;
• and
• a protruding frame;
• wherein the bottom electrode, the piezoelectric layer, the top layer, and the etching insertion layer are arranged along a thickness direction of the piezoelectric film bulk acoustic resonator;
• the bottom electrode is located on one side of the substrate, the piezoelectric layer covers one side of the bottom electrode away from the substrate, the top electrode is located on one side of the piezoelectric layer away from the bottom electrode, the etching insertion layer is located on one side of the top electrode away from the piezoelectric layer, and the protruding frame is located on one side of the etching insertion layer away from the top electrode;
• a stacking area of the bottom electrode, the piezoelectric layer, the top electrode, and the etching insertion layer constitutes an effective source area of the piezoelectric film bulk acoustic resonator;
• and
• an extending portion is disposed on at least one of the etching insertion layer and the protruding frame, the extending portion is located at an edge of the effective source area, and the extending portion extends towards a direction away from the effective source area along a direction perpendicular to the thickness direction of the piezoelectric thin film bulk acoustic resonator.