Bulk acoustic wave resonator capable of improving power capacity and preparation method thereof

A bulk acoustic wave resonator capable of improving a power capacity, comprising a substrate, a first diamond film layer, a piezoelectric layer and a second diamond film layer sequentially from bottom to top, wherein a first cavity is formed in the first diamond film layer;

• a bottom electrode is arranged on an upper surface of the first diamond film layer and located in the piezoelectric layer, and the bottom electrode is partially exposed to the first cavity;
• a second cavity is formed in the second diamond film layer, and a top electrode is arranged in the second cavity and located on an upper surface of the piezoelectric layer;
• a first through hole is formed between the top electrode and the bottom electrode, and the first through hole penetrates through the top electrode and the bottom electrode, and communicates with the first cavity and the second cavity;
• and a second through hole is further formed in the second diamond film layer, and the second through hole communicates with the second cavity and outside.