Proximity micro-electro-mechanical system

• US 6,608,268 B1
• Filed: 02/05/2002
• Issued: 08/19/2003
• Est. Priority Date: 02/05/2002
• Status: Active Grant

• Current Assignee: Memtronics, a Division Of Cogent Solutions, Inc.
• Original Assignee: Memtronics, a Division Of Cogent Solutions, Inc.
• Inventors: Goldsmith, Charles L.
• Primary Examiner(s): Enad, Elvin
• Assistant Examiner(s): HOMZA, LISA NHUNG
• Application Number:
  US10/068,399
• Publication Number:
  US 20030146079A1
• Time in Patent Office: 560 Days
• Field of Search: 200/181, 200/257, 200/512, 200/269, 335/78, 257/780
• US Class Current: 200/181
• CPC Class Codes: H01H 2059/0018 Special provisions for avoiding charge trapping, e.g. insulation layer between actuating electrodes being permanently polarised by charge trapping so that actuating or release voltage is altered
• CPC Class Codes: H01H 2059/0072 with stoppers or protrusions for maintaining a gap, reducing the contact area or for preventing stiction between the movable and the fixed electrode in the attracted position
• CPC Class Codes: H01H 59/0009 making use of micromechanics
• CPC Class Codes: H01P 1/127 Strip line switches

Abstract

A proximity micro-electro-mechanical system (MEMS) utilizing a gaseous capacitive gap between two conductive members. The gaseous gap is maintained by insulating structures that prevent the two conductive members from shorting. Once actuated, the gaseous gap allows high-frequency signals to be transmitted between the two conductive members.

Claims

1. An apparatus comprising:

a first electrode;

a second electrode configured to be displaced toward the first electrode in response to the application of a voltage differential with respect to the first electrode;

one or more insulating structures, wherein at least a portion of the insulating structures prevent the second electrode from contacting the first electrode; and

a gaseous capacitive gap is formed and maintained between the first and second electrodes when the voltage differential is applied.

2. The apparatus of claim 1, further comprising means for discontinuing the application of the voltage differential after charging the gaseous capacitive gap.

3. The apparatus of claim 1, further comprising:

means for discontinuing the application of the voltage differential after charging the gaseous capacitive gap; and

means for discharging the gaseous capacitive gap.

4. The apparatus of claim 1, wherein the second electrode comprises a flexible membrane suspended over the first electrode.

5. The apparatus of claim 1, wherein the second electrode comprises a cantilever.

6. An apparatus comprising:

one or more electrodes;

one or more insulating structures;

an electrically conductive member suspended above the electrodes, wherein at least a portion of the insulating structures prevent the electrically conductive member from contacting the electrodes, wherein the electrically conductive member is attracted to the electrodes when a voltage is applied to the electrode, and wherein a gaseous capacitive gap between the electrically conductive member and the electrodes is maintained when voltage is applied to the electrode.

7. The apparatus of claim 6, further comprising means for disconnecting the voltage after charging the gaseous capacitive gap.

8. The apparatus of claim 6, further comprising:

means for disconnecting the voltage after charging the gaseous capacitive gap; and

means for discharging the gaseous capacitive gap.

9. The apparatus of claim 6, wherein the insulating structures comprise a dielectric material deposited on the electrodes.

10. The apparatus of claim 6, wherein the insulating structures are not electrically coupled to the electrodes.

11. The apparatus of claim 6, wherein the insulating structures comprise a dielectric material deposited on an electrically conductive material that is not electrically coupled to the electrodes.

12. The apparatus of claim 6, wherein the insulating structures are coupled to the electrically conductive member.

13. The apparatus of claim 12, wherein the electrically conductive member comprises a flexible membrane.

14. The apparatus of claim 12, wherein the electrically conductive member comprises a cantilever.

15. The apparatus of claim 13 or 14, wherein the insulating structures comprise a dielectric material coupled to the electrically conductive member.

16. The apparatus of claim 6, further comprising a dielectric layer deposited on the electrode.

17. The apparatus of claim 6, wherein the electrically conductive member comprises at least one of aluminum, gold, copper, platinum, and nickel.

18. The apparatus of claim 6, wherein the electrode comprises at least one of aluminum, gold, copper, platinum, and nickel.

19. The apparatus of claim 6, wherein the insulating structures comprise at least one of silicon nitride and silicon dioxide.

20. The apparatus of claim 6, wherein the gaseous capacitive gap comprises at least one of air, nitrogen, inert gasses, and noble gases.

21. An apparatus comprising:

a substrate with a cavity formed therein;

one or more electrodes placed within the cavity;

one or more insulating structures having a portion positioned above the-surface of the electrodes; and

a conductive member having a flexible portion wherein the conductive member is suspended by the flexible portion above the electrodes, wherein a gaseous space is maintained intermediate the conductive member and the electrodes.

22. The apparatus of claim 21, wherein the insulating structures comprises a dielectric material deposited on the electrodes.

23. The apparatus of claim 21, wherein the insulating structures are not electrically coupled to the electrodes.

24. The apparatus of claim 21, wherein the insulating structures comprise a dielectric material deposited on a conductive material that is not electrically coupled to the electrodes.

25. The apparatus of claim 21, wherein the insulating structures are couple ed to the conductive member.

26. The apparatus of claim 21, further comprising a dielectric layer deposited on the electrodes.

27. The apparatus of claim 21, wherein the conductive member is either a flexible membrane or a cantilever.

28. A method of providing micro-electro-mechanical switching of high-frequency signals, the method comprising the steps of:

suspending a conductive, flexible membrane over an electrode, creating a switch;

actuating the switch by applying voltage to the electrode, wherein the voltage causes the flexible membrane to be attracted to the electrode, wherein the flexible membrane is prevented from contacting the electrode by at least a portion of one or more insulating structures, and wherein a gaseous capacitive gap is maintained between the flexible membrane and the electrode thereby allowing high-frequency signals to be transmitted to the electrode.

29. The method of claim 28, further comprising disconnecting the voltage when the gaseous capacitive gap is charged.

30. The method of claim 28, wherein the insulating structures comprise a dielectric material deposited on the electrodes.

31. The method of claim 28, wherein the insulating structures are not electrically coupled to the electrode.

32. The method of claim 28, wherein the insulating structures comprise a dielectric material deposited on a conductive material that is not electrically coupled to the electrodes.

33. The method of claim 28, wherein the insulating structures are coupled to the flexible membrane.

34. The method of claim 28, the electrodes comprise a conductive material covered by a dielectric layer.

35. A method of providing micro-electro-mechanical switching of high-frequency signals, the method comprising the steps of:

suspending a conductive cantilever having a flexible portion over an electrode, creating a switch;

actuating the switch by applying voltage to the electrode, wherein the voltage causes the flexible portion of the cantilever to flex the cantilever toward the electrode, wherein the cantilever is prevented from contacting the electrode by at least a portion of one or more insulating structures, and wherein a gaseous capacitive gap is maintained between the cantilever and the electrode thereby allowing high-frequency signals to be transmitted to the electrode.

36. The method of claim 35, further comprising disconnecting the voltage when the gaseous capacitive gap is charged.

37. The method of claim 35, wherein the insulating structures comprise a dielectric material deposited on the electrodes.

38. The method of claim 35, wherein the insulating structures are not electrically coupled to the electrode.

39. The method of claim 35, wherein the insulating structures comprise a dielectric material deposited on a conductive material that is not electrically coupled to the electrodes.

40. The method of claim 35, wherein the insulating structures are coupled to the cantilever.

41. The method of claim 35, the electrodes comprise a conductive material covered by a dielectric layer.

42. An apparatus, comprising:

a first electrically conductive member;

a second electrically conductive member; and

a gaseous gap providing a capacitance formed and maintained between the first and second electrically conductive members, the gap allowing high-frequency signals to be transmitted between the first and second members.

43. The apparatus of claim 42, further comprising at least one insulating structure for separating the first and second electrically conductive members to maintain the gaseous capacitive gap.

44. The apparatus of claim 43, wherein the insulating structure does not retain sufficient dielectric charging to substantially degrade the capacitance of the gaseous gap.