Acoustic wave resonator

1. An acoustic wave resonator, comprising:

a resonance active region spaced apart from a substrate by a cavity, the resonance active region comprising a sequentially stacked, in at least a vertical direction, first electrode layer, piezoelectric layer, and second electrode layer;

a membrane layer, wherein a portion of the membrane layer forms an upper side portion of the cavity; and

plural passages respectively connecting the cavity to an outside, each of the plural passages including a respective outside access to the outside, separated from a perimeter of the resonance active region, a horizontal tunnel, and a respective cavity access of the cavity,

wherein an expression of 30 μm≤Ra/Hw≤200 μm is met, Ra being a total area (μm2) within the perimeter of the resonance active region, and Hw being a total length (μm) of all of the respective cavity accesses along the perimeter of the resonance active region.

2. The acoustic wave resonator of claim 1 , further comprising respective connection electrodes, connecting to outside of the resonance active region, of the first electrode and the second electrode,

wherein Hw is greater than or equal to a total width of the respective connection electrodes along a periphery of the resonance active region.

3. The acoustic wave resonator of claim 2 , wherein the resonance active region has a polygonal shape, and the plural passages extend in respective directions away from the polygonal shape of the resonance active region.

4. The acoustic wave resonator of claim 3 , wherein the perimeter of the resonance active region has a square shape, and the total area (μm2) within the perimeter of the resonance active region is a square of lengths (μm) of two sides of the perimeter of the resonance active region.

5. The acoustic wave resonator of claim 2 , wherein the total width of the respective connection electrodes is greater than or equal to 120 μm.

6. The acoustic wave resonator of claim 1 , wherein the portion of the membrane layer forming the upper side portion of the cavity has corresponding layer thickness differences, where a difference between a maximum layer thickness and a minimum layer thickness of the portion of the membrane layer is ΔMg, wherein 0 Å<ΔMg<170 Å.

7. The acoustic wave resonator of claim 6 , wherein ΔMg is greater than 10 Å.

8. The acoustic wave resonator of claim 7 , wherein ΔMg is less than 50 Å.

9. The acoustic wave resonator of claim 6 , wherein ΔMg is greater than 50 Å and less than 100 Å.

10. The acoustic wave resonator of claim 1 , wherein Ra/Hw is less than 175 μm.

11. The acoustic wave resonator of claim 10 , wherein Ra/Hw is greater than 125 μm and less than 160 μm.

12. The acoustic wave resonator of claim 1 , further comprising a frame formed on the second electrode, and the perimeter of the resonance active region is within a perimeter of the frame.

13. An acoustic wave resonator, comprising:

a resonance part disposed on and spaced apart from a substrate by a cavity, the resonance part comprising a membrane layer, a first electrode, a piezoelectric layer, and a second electrode that are sequentially stacked on the cavity,

wherein a thickness deviation of the membrane layer is expressed as 0 Å<ΔMg<170 Å, where ΔMg is a difference between a maximum layer thickness and a minimum layer thickness of a surface of the membrane layer disposed on the cavity,

wherein the cavity comprises one or more tunnels respectively traversing partially below the membrane layer to connect a periphery of the cavity to the outside, and

wherein respective thicknesses of the membrane layer along a length of a portion of the membrane layer decrease from the maximum layer thickness of the membrane layer outward, from a central portion of a resonance active region of the resonance part toward a perimeter of the resonance active region to provide corresponding increasing cavity vertical gap sizes outward toward the perimeter of the cavity.

14. The acoustic wave resonator of claim 13 , wherein 30 μm≤Ra/Hw≤200 is satisfied, Ra being a total area (μm2) within a perimeter of a resonance active region of the resonance part, and Hw being a total length (μm) of the one or more tunnels along the perimeter of the resonance active region.

15. The acoustic wave resonator of claim 14 , wherein Ra/Hw is greater than 125 μm.

16. The acoustic wave resonator of claim 14 , wherein Ra/Hw is less than 175 μm.

17. The acoustic wave resonator of claim 14 , wherein Ra/Hw is less than 160 μm.

18. The acoustic wave resonator of claim 13 , wherein ΔMg is greater than 10 Å.

19. The acoustic wave resonator of claim 18 , wherein ΔMg is less than 50 Å.

20. The acoustic wave resonator of claim 13 ,

where a cavity vertical gap deviation is within a range of 10 Å<ΔCg≤340 Å, where ΔCg is a difference between a maximum vertical gap and a minimum vertical gap of the portion of the cavity vertically aligned with the resonance active region.

21. The acoustic wave resonator of claim 13 , wherein ΔMg is greater than 50 Å and less than 100 Å.

22. An acoustic wave resonator, comprising:

a resonance active region spaced apart from a substrate by a cavity, the resonance active region comprising a sequentially stacked first electrode layer, piezoelectric layer, and second electrode layer;

a membrane layer, wherein a portion of the membrane layer forms an upper side portion of the cavity; and

plural passages respectively connecting the cavity to an outside, each of the plural passages including a respective outside access to the outside, separated from a perimeter of the resonance active region, and a respective cavity access of the cavity,

wherein an expression of 125 μm<Ra/Hw<160/μm is met, Ra being a total area (μm2) within the perimeter of the resonance active region, and Hw being a total length (μm) of all of the respective cavity accesses along the perimeter of the resonance active region.