Methods of manufacturing acoustic wave resonators with isolation
Embodiments of this disclosure relate to methods of manufacturing acoustic wave components that include acoustic wave resonators that share a substrate. Laser light can be applied to alter a region of the substrate that is located between two of the acoustic wave resonators. Altering the region with laser light can reduce coupling between the two acoustic resonators through the substrate. The substrate can be monolithic after laser the light is applied.
1. A method of manufacturing an acoustic wave component that includes acoustic wave resonators, the method comprising:
providing a first acoustic wave resonator and a second acoustic resonator, the first acoustic wave resonator and the second acoustic wave resonator sharing a substrate; and
applying, with a laser, laser light to alter a region of the substrate located between the first acoustic wave resonator and the second acoustic wave resonator, the region of the substrate to which the laser light is applied being solid after the applying and the substrate being monolithic after the applying.
2. The method of claim 1 wherein the first acoustic wave resonator is a first surface acoustic wave resonator, and the second acoustic wave resonator is a second surface acoustic wave resonator.
3. The method of claim 2 wherein the substrate is a lithium niobate substrate.
4. The method of claim 2 wherein the substrate is a lithium tantalate substrate.
5. The method of claim 1 wherein the first acoustic wave resonator is included in a first filter, and the second acoustic wave resonator is included in the second filter.
6. The method of claim 5 wherein the first filter and the second filter are coupled to each other at a common node, and the first filter and the second filter are included in a multiplexer.
7. The method of claim 1 further comprising aligning the laser to a feature on the substrate before the applying.
8. The method of claim 1 further comprising performing wafer level packaging after the applying.
9. The method of claim 1 wherein the region extends only part way through a thickness of the substrate.
10. The method of claim 1 wherein the region has a lower dielectric constant than other regions of the substrate.
11. The method of claim 1 wherein the substrate has a crystalline structure that is disrupted in the region.
12. The method of claim 1 wherein the region of the substrate is amorphous after the applying.
13. The method of claim 1 wherein the region of the substrate is polycrystalline after the applying.
14. The method of claim 1 wherein the substrate is a piezoelectric substrate having a crystalline structure, and the applying causes the crystalline structure in the region to undergo a phase change to a state with a lower dielectric constant than before the applying.
15. A method of manufacturing an acoustic wave component, the method comprising:
forming a first acoustic wave resonator and a second acoustic resonator that share a substrate;
aligning a laser to a feature on the substrate;
applying, with the laser, laser light to alter a region of the substrate located between the first acoustic wave resonator and the second acoustic wave resonator, the region of the substrate to which the laser light is applied being amorphous or polycrystalline after the applying; and
after the applying, packaging the first acoustic wave resonator and the second acoustic wave resonator to form a packaged acoustic wave component.
16. The method of claim 15 wherein the first acoustic wave resonator is a first surface acoustic wave resonator, and the second acoustic wave resonator is a second acoustic wave resonator.
17. The method of claim 15 wherein the substrate is a lithium based piezoelectric substrate.
18. The method of claim 15 wherein the region extends through some but not all of a thickness of the substrate.
19. The method of claim 15 wherein the first acoustic wave resonator is included in a first filter, a second acoustic wave resonator is included in a second filter, and the region is located between the first filter and the second filter.
20. A method of manufacturing a surface acoustic wave component, the method comprising:
providing a piezoelectric substrate with a first interdigital transducer electrode of a first surface acoustic wave resonator and a second interdigital transducer electrode of a second surface acoustic resonator thereon;
aligning a laser to a feature on the piezoelectric substrate; and
applying, with the laser, laser light to alter a region of the piezoelectric substrate located between the first interdigital transducer electrode and the second interdigital transducer electrode to cause a phase change in the region of the piezoelectric substrate and thereby reduce a dielectric constant of the region, the region to which the laser light is applied being solid after the applying and the piezoelectric substrate being monolithic after the applying.
21. The method of claim 20 wherein the feature is at least part of the first interdigital transducer electrode.
22. The method of claim 20 wherein the providing includes providing the piezoelectric substrate attached to a support substrate.
23. The method of claim 20 wherein the first surface acoustic wave resonator is included in a transmit filter of a multiplexer, the second surface acoustic wave resonator is included in a receive filter of the multiplexer, and the region is located between the transmit filter and the receive filter.