Thin-film bulk acoustic resonator and semiconductor apparatus comprising the same

A semiconductor apparatus, comprising:

• an isolation trench layer;
• a first dielectric layer formed on the isolation trench layer;
• a lower electrode layer formed on the first dielectric layer, wherein the lower electrode layer is above the isolation trench layer;
• a piezoelectric film formed on the lower electrode layer;
• an upper electrode layer formed on the piezoelectric film;
• a protection layer formed to cover the side and upper surfaces of the upper electrode layer, the side surface of the piezoelectric film, and part of the upper surface of the lower electrode layer;
• a second dielectric layer formed on the first dielectric layer and the protection layer;
• a third dielectric layer formed on the second dielectric layer;
• a first cavity formed above the isolation trench layer, the first cavity being an enclosed structure extending through the third dielectric layer, the second dielectric layer, and the protection layer, to the upper electrode layer and having a first polygonal shape in plan view;
• a fourth dielectric layer formed under the isolation trench layer;
• a second cavity formed under the piezoelectric film, the second cavity being an enclosed structure extending through the fourth dielectric layer, the isolation trench layer, and the first dielectric layer to part of the lower electrode layer and having a second polygonal shape in plan view, wherein the first and second cavities are facing each other, their plan views overlap to form an overlapped region having a shape of a third polygon without parallel sides;
• and
• an acoustic resonance film comprising of the lower electrode layer, the piezoelectric film, and the upper electrode layer.