Film bulk acoustic resonator

A film bulk acoustic resonator, comprising:

• a substrate;
• an acoustic reflection structure arranged on one side of the substrate;
• a bottom electrode stacked on one side of the acoustic reflection structure;
• a piezoelectric film covered on the bottom electrode;
• and
• a top electrode stacked on a side of the piezoelectric film away from the bottom electrode;
• wherein an interdigital protrusion frame is provided on a side of the top electrode away from the piezoelectric film, and the interdigital protrusion frame comprises a first protrusion frame and a second protrusion frame arranged at intervals;
• the first protrusion frame and the second protrusion frame respectively extend toward each other and overlap each other to form at least a pair of interdigital structures, and each of the interdigital structures comprises two forks spaced apart by a preset distance along an overlapping direction;
• the interdigital structures comprise a first extending protrusion and a second extending protrusion which are connected to a side of the first protrusion frame close to the second protrusion frame and are arranged at intervals, a third extending protrusion and a fourth extending protrusion which are connected to a side of the second protrusion frame close to the first protrusion frame and are arranged at intervals, wherein the first extending protrusion and the third extending protrusion are spaced apart by the preset distance and overlap to form an interdigital structure, and the second extending protrusion and the fourth extending protrusion are spaced apart.