Capacitive microelectromechanical switches

• US 6,452,124 B1
• Filed: 06/28/2001
• Issued: 09/17/2002
• Est. Priority Date: 06/28/2000
• Status: Expired due to Fees

• Current Assignee: Regents of the University of California (University of California)
• Original Assignee: Regents of the University of California (University of California)
• Inventors: Borgioli, Andrea, York, Robert A., Nagra, Amit S.
• Primary Examiner(s): FRIEDHOFER, MICHAEL A
• Application Number:
  US09/895,105
• Publication Number:
  US 20020027064A1
• Time in Patent Office: 446 Days
• Field of Search: 200/181, 257/295, 257/296, 257/301, 257/303, 257/308, 257/414, 257/421, 257/531, 335/78, 335/128, 335/298.1, 335/298.2, 335/298.3, 335/296, 335/290, 335/301.4, 335/306.3, 335/311, 335/306.1, 335/312, 335/313, 335/299.2, 335/321--32, 335/233, 335/234, 335/235, 438/48, 438/50, 296/22
• US Class Current: 200/181
• CPC Class Codes: H01G 5/18 due to change in inclination, e.g. by flexing, by spiral wrapping
• CPC Class Codes: H01H 59/0009 making use of micromechanics
• CPC Class Codes: Y10T 29/49105 Switch making

Abstract

A microelectromechanical switch is disclosed comprising a conductor, a dielectric layer disposed on the conductor, a metal cap disposed on the dielectric layer and a bridge disposed proximate to the metal cap such that an electrical potential applied between the bridge and conductor causes the bridge to deform and contact the metal cap.

Claims

1. A microelectromechanical switch, comprising:

a conductor;

a dielectric layer disposed on the conductor;

a metal cap disposed on the dielectric layer; and

a bridge disposed proximate to the metal cap such that an electrical potential applied between the bridge and the conductor causes the bridge to deform and contact the metal cap.

2. The microelectromechanical switch of claim 1, wherein the bridge is a cantilever.

3. The microelectromechanical switch of claim 1, wherein the bridge is a membrane.

4. The microelectromechanical switch of claim 1, wherein the dielectric layer creates capacitive coupling when the bridge is deformed to contact the metal cap to produce an effective short at a predetermined frequency.

5. The microelectromechanical switch of claim 1, wherein the dielectric layer is thickened, thereby increasing a break-down voltage of the switch.

6. The microelectromechanical switch of claim 1, wherein the metal cap is patterned directly onto the dielectric layer.

7. The microelectromechanical switch of claim 1, wherein the metal cap has an extended area beyond an area of bridge.

8. The microelectromechanical switch of claim 1, wherein a DOWN state capacitance is determined by an area of the metal cap.

9. The microelectromechanical switch of claim 1, wherein the metal cap includes a notch proximate to the bridge.

10. The microelectromechanical switch of claim 9, wherein the bridge contacts the notch of the metal cap when deformed.

11. A method of producing a microelectromechanical switch, comprising the steps of:

forming a conductor on a substrate;

disposing a dielectric layer on the conductor;

forming a metal cap on the dielectric layer; and

disposing a bridge proximate to the metal cap such that an electrical potential applied between the bridge and the conductor causes the bridge to deform and contact the metal cap.

12. The method of claim 11, wherein the bridge is a cantilever.

13. The method of claim 11, wherein the bridge is a membrane.

14. The method of claim 11, wherein the dielectric layer creates capacitive coupling when the bridge is deformed to contact the metal cap to produce an effective short at a predetermined frequency.

15. The method of claim 11, wherein the dielectric layer is thickened thereby increasing a break-down voltage of the switch.

16. The method of claim 11, wherein the metal cap is patterned directly onto the dielectric layer.

17. The method of claim 11, wherein the metal cap has an extended area beyond an area of bridge.

18. The method of claim 11, wherein a DOWN state capacitance is determined by an area of the metal cap.

19. The method of claim 11, wherein the metal cap includes a notch proximate to the bridge.

20. The method of claim 19, wherein the bridge contacts the notch of the metal cap when deformed.