Method of manufacturing switchable filters

1. A method comprising:

forming at least one piezoelectric filter structure comprising a plurality of electrodes formed on a piezoelectric substrate;

forming a micro-electro-mechanical structure (MEMS) comprising a MEMS beam formed above the piezoelectric substrate and at a location in which, upon actuation, the MEMS beam shorts the piezoelectric filter structure by contacting at least one of the plurality of electrodes;

forming a bottom actuator on the piezoelectric substrate, below the MEMS beam; and

forming a top actuator on an insulator layer, above the MEMS beam.

2. The method of claim 1 , wherein the at least one piezoelectric filter structure is a surface acoustic wave (SAW) filter.

3. The method of claim 2 , wherein forming the SAW filter comprises:

forming a Vin interdigital transducer (IDT) comprising interleaved signal and ground electrodes on a surface of the piezoelectric substrate; and

forming a Vout IDT comprising interleaved signal and ground electrodes on the surface of the piezoelectric substrate.

4. The method of claim 3 , wherein forming the MEMS beam comprises positioning the MEMS beam to short the interleaved signal and ground electrodes of the Vin IDT or Vout IDT, upon actuation.

5. The method of claim 3 , wherein forming the MEMS beam comprises positioning the MEMS beam above respective ground electrodes of the Vin IDT and the Vout IDT.

6. The method of claim 3 , wherein the ground electrode of the Vin IDT is formed as a pull in actuator for the MEMS beam.

7. The method of claim 1 , wherein the piezoelectric filter structure is a bulk acoustic wave (BAW) filter.

8. The method of claim 1 , wherein forming the MEMS beam comprises depositing and patterning a metal material on a sacrificial material, formed over the plurality of electrodes.

9. The method of claim 1 , wherein forming of the MEMS beam is a composite beam structure formed by depositing and patterning metal and insulator material over a sacrificial material, formed over the plurality of electrodes.

10. The method of claim 1 , wherein the MEMS beam is formed as a cantilever beam, positioned between actuators and perpendicular to interleaved electrodes of the at least one piezoelectric filter structure.

11. The method of claim 1 , wherein the MEMS beam covers substantially an entire area of the electrodes of the at least one piezoelectric filter structure.

12. The method of claim 11 , wherein a ground electrode of the electrodes is formed as a pull in actuator of the MEMS beam.

13. The method of claim 1 , wherein the top actuator and the bottom actuator are positioned beyond an outmost of the plurality of electrodes.

14. The method of claim 1 , wherein the top actuator and the bottom actuator are formed spaced apart from the MEMS beam in an unactuated state.

15. The method of claim 1 , wherein forming the MEMS beam comprises:

forming an insulator layer over interleaved electrodes of the least one piezoelectric filter structure;

patterning the insulator layer to expose the interleaved electrodes;

depositing a sacrificial material in the pattern of the insulator layer and over the interleaved electrodes;

forming a beam structure on the sacrificial material, which is positioned over the interleaved electrodes of the least one piezoelectric filter structure;

forming a second insulator layer on the beam structure, and patterning the second insulator layer to expose surfaces of the beam structure;

forming additional sacrificial material in the pattern of the second insulator layer and over the beam structure;

forming a capping layer over the additional sacrificial material;

forming at least one vent hole in the capping layer;

venting the sacrificial material and the additional sacrificial material through the at least one vent hole to form an upper cavity and a lower cavity about the beam structure; and

closing the at least one vent hole with material.

16. The method of claim 1 , wherein forming the MEMS beam comprises:

forming electrodes on a first piezoelectric substrate, wherein one of the electrodes is structured as an actuator of the MEMS beam;

forming a wiring layer on a second piezoelectric substrate;

forming a sacrificial material on the second piezoelectric substrate;

forming a beam structure on the sacrificial material and in contact with the wiring layer;

removing the sacrificial material to form a space between the beam structure and the second piezoelectric substrate; and

bonding the first piezoelectric substrate to the second piezoelectric substrate by a solder material such that a space is provided between the beam structure and the first piezoelectric substrate,

wherein the actuator of the MEMS beam is aligned with the beam structure.

17. A method comprising:

forming at least one piezoelectric filter structure comprising a plurality of electrodes formed on a piezoelectric substrate; and

forming a micro-electro-mechanical structure (MEMS) comprising a MEMS beam formed above the piezoelectric substrate and at a location in which, upon actuation, the MEMS beam shorts the piezoelectric filter structure by contacting at least one of the plurality of electrodes, wherein forming the MEMS beam comprises:

forming an insulator layer over interleaved electrodes of the least one piezoelectric filter structure;

patterning the insulator layer to expose the interleaved electrodes;

depositing a sacrificial material in the pattern of the insulator layer and over the interleaved electrodes;

forming a beam structure on the sacrificial material, which is positioned over the interleaved electrodes of the least one piezoelectric filter structure;

forming a second insulator layer on the beam structure, and patterning the second insulator layer to expose surfaces of the beam structure;

forming additional sacrificial material in the pattern of the second insulator layer and over the beam structure;

forming a capping layer over the additional sacrificial material;

forming at least one vent hole in the capping layer;

venting the sacrificial material and the additional sacrificial material through the at least one vent hole to form an upper cavity and a lower cavity about the beam structure; and

closing the at least one vent hole with material.

18. A method comprising:

forming at least one piezoelectric filter structure comprising a plurality of electrodes formed on a piezoelectric substrate; and

forming a micro-electro-mechanical structure (MEMS) comprising a MEMS beam formed above the piezoelectric substrate and at a location in which, upon actuation, the MEMS beam shorts the piezoelectric filter structure by contacting at least one of the plurality of electrodes, wherein forming the MEMS beam comprises:

forming electrodes on a first piezoelectric substrate, wherein one of the electrodes is structured as an actuator of the MEMS beam;

forming a wiring layer on a second piezoelectric substrate;

forming a sacrificial material on the second piezoelectric substrate;

forming a beam structure on the sacrificial material and in contact with the wiring layer;

removing the sacrificial material to form a space between the beam structure and the second piezoelectric substrate; and

bonding the first piezoelectric substrate to the second piezoelectric substrate by a solder material such that a space is provided between the beam structure and the first piezoelectric substrate,

wherein the actuator of the MEMS beam is aligned with the beam structure.