SYSTEMS AND METHODS FOR PROVIDING HIGH-CAPACITANCE RF MEMS SWITCHES

• US 20110259717A1
• Filed: 04/22/2010
• Published: 10/27/2011
• Est. Priority Date: 04/22/2010
• Status: Active Grant

• Current Assignee: Raytheon Company (Rtx Corporation)
• Original Assignee: Raytheon Company (Rtx Corporation)
• Inventors: MORRIS, Francis J., PILLANS, Brandon W., WHITE, Mikel J.
• Granted Patent: US 8,368,491 B2
• Time in Patent Office: Days
• US Class Current: 200/181
• CPC Class Codes: H01G 5/16 using variation of distance between electrodes
• CPC Class Codes: H01H 11/00 Apparatus or processes specially adapted for the manufacture of electric switches processes specially adapted for manufacture of rectilinearly movable switches having a plurality of operating members associated with different sets of contacts, e.g. keyboards, H01H13/88
• CPC Class Codes: H01H 57/00 Electrostrictive relays; Piezoelectric relays
• CPC Class Codes: Y10T 29/49105 Switch making

Abstract

Systems and methods for providing high-capacitive RF MEMS switches are provided. In one embodiment, the invention relates to a micro-electro-mechanical switch assembly including a substrate, an electrode disposed on a portion of the substrate, a dielectric layer disposed on at least a portion of the electrode, a metal layer disposed on at least a portion of the dielectric layer, and a flexible membrane having first and second ends supported at spaced locations on the substrate base, where the flexible membrane is configured to move from a default position to an actuated position in response to a preselected switching voltage applied between the flexible membrane and the electrode, and where, in the actuated position, the flexible membrane is in electrical contact with the metal layer.

Claims

1. A micro-electro-mechanical switch assembly comprising:

a substrate;

an electrode disposed on a portion of the substrate;

a dielectric layer disposed on at least a portion of the electrode;

a metal layer disposed on at least a portion of the dielectric layer; and

a flexible membrane having first and second ends supported at spaced locations on the substrate base,

wherein the flexible membrane is configured to move from a default position to an actuated position in response to a preselected switching voltage applied between the flexible membrane and the electrode, and

wherein, in the actuated position, the flexible membrane is in electrical contact with the metal layer.

2. The switch assembly of claim 1, wherein the metal layer is not in contact with the electrode.

3. The switch assembly of claim 1, wherein the flexible membrane is configured to return to the default position in response to removal of the preselected switching voltage.

4. The switch of claim 1, wherein a capacitive coupling, of signals traveling along the electrode to signals traveling along the flexible membrane, in the actuated position is substantially greater than the capacitive coupling in the default position.

5. The switch assembly of claim 1, wherein, in the default position, the flexible membrane is not in contact with the metal layer.

6. The switch assembly of claim 1, wherein the metal layer comprises a patterned layer.

7. The switch assembly of claim 6, wherein the patterned layer comprises a plurality of openings.

8. The switch assembly of claim 1, further comprising a bias control circuitry configured to supply the preselected switching voltage.

9. The switch assembly of claim 1, wherein the flexible membrane comprises a conductive material.

10. The switch assembly of claim 9, wherein the conductive material is a metal.

11. The switch assembly of claim 9, wherein the flexible membrane comprises a conductive material.

12. The switch assembly of claim 11, wherein the flexible membrane comprises aluminum.

13. The switch assembly of claim 1, wherein the dielectric layer comprises a high dielectric material.

14. The switch assembly of claim 13, wherein the dielectric layer comprises silicon nitride, tantalum pentoxide, alumina, or combinations thereof.

15. The switch assembly of claim 1, further comprising at least one air gap positioned between the metal layer and the flexible membrane in the actuated position.

16. The switch assembly of claim 1, wherein the first and second ends are supported using a plurality of posts.

17. A method for manufacturing a micro-electro-mechanical switch assembly comprising:

depositing an electrode material on a surface of a substrate;

depositing a dielectric material on at least a portion of a surface of the electrode material;

depositing a metal layer on at least a portion of a surface of the dielectric layer;

depositing a plurality of posts on the substrate at positions spaced apart from the electrode material;

depositing a spacer material on the metal layer and between the posts;

depositing a flexible membrane on the spacer material and the posts; and

etching the spacer material from the assembly.

18. The method of claim 17, wherein the depositing the electrode material on the surface of the substrate comprises depositing and patterning the electrode material on the surface of the substrate.

19. The method of claim 17, wherein the depositing the dielectric material on the at least the portion of the surface of the electrode material comprises depositing and patterning the dielectric material on the at least the portion of the surface of the electrode material.

20. The method of claim 17, wherein the depositing the metal layer on the at least the portion of the surface of the dielectric layer comprises depositing and patterning the metal layer on the at least the portion of the surface of the dielectric layer.

21. The method of claim 20, wherein the patterned metal layer comprises a plurality of openings.

22. The method of claim 17, wherein the flexible membrane is configured to move from a default position to an actuated position in response to a preselected switching voltage applied between the flexible membrane and the electrode.

23. The method of claim 22, wherein, in the actuated position, the flexible membrane is in contact with the metal layer.

24. The method of claim 22, wherein the flexible membrane is configured to return to the default position in response to removal of the preselected switching voltage.

25. The method of claim 22, wherein, in the default position, the flexible membrane is not in contact with the metal layer.

26. The method of claim 22, wherein a capacitive coupling, of signals traveling along the electrode to signals traveling along the flexible membrane, in the actuated position is substantially greater than the capacitive coupling in the default position.

27. The method of claim 17, wherein the metal layer is not in contact with the electrode.