MEMS device having a trilayered beam and related methods

• US 20030116848A1
• Filed: 11/08/2002
• Published: 06/26/2003
• Est. Priority Date: 11/09/2001
• Status: Active Grant

• Current Assignee: AAC Technologies Pte Limited (AAC Technologies Holdings Inc.)
• Original Assignee: Coventor, Inc. (Lam Research Corporation)
• Inventors: DeReus, Dana Richard, Sett, Subham, Cunningham, Shawn Jay, Tatic-Lucic, Svetlana
• Granted Patent: US 6,876,047 B2
• Time in Patent Office: Days
• US Class Current: 257/747
• CPC Class Codes: B81B 2201/014 having a cantilever fixed on one side connected to one or more dimples
• CPC Class Codes: B81B 2201/018 Switches not provided for in B81B2201/014 - B81B2201/016
• CPC Class Codes: B81B 2203/0118 Cantilevers
• CPC Class Codes: B81B 2203/04 Electrodes
• CPC Class Codes: B81B 2207/07 Interconnects
• CPC Class Codes: B81B 3/0024 Transducers for transforming thermal into mechanical energy or vice versa, e.g. thermal or bimorph actuators electric motors using thermal effects H02N10/00
• CPC Class Codes: B81B 3/0051 For defining the movement, i.e. structures that guide or limit the movement of an element mechanical arrangements for preventing or damping vibration or shock H01H3/60
• CPC Class Codes: B81C 1/0015 Cantilevers switches using MEMS H01H1/0036; electrostatic relays using micromechanics H01H59/0009; microelectro-mechanical resonators H03H9/02244
• CPC Class Codes: B81C 2201/0107 Sacrificial metal
• CPC Class Codes: B81C 2201/0108 Sacrificial polymer, ashing of organics
• CPC Class Codes: B81C 2201/0109 Sacrificial layers not provided for in B81C2201/0107 - B81C2201/0108
• CPC Class Codes: H01H 1/04 Co-operating contacts of different material
• CPC Class Codes: H01H 1/504 by thermal means
• CPC Class Codes: H01H 2001/0042 Bistable switches, i.e. having two stable positions requiring only actuating energy for switching between them, e.g. with snap membrane or by permanent magnet
• CPC Class Codes: H01H 2001/0063 having electrostatic latches, i.e. the activated position is kept by electrostatic forces other than the activation force
• CPC Class Codes: H01H 2001/0089 Providing protection of elements to be released by etching of sacrificial element; Avoiding stiction problems, e.g. of movable element to substrate
• 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 2061/006 Micromechanical thermal relay
• CPC Class Codes: H01H 59/0009 making use of micromechanics
• CPC Class Codes: H01H 61/04 wherein the thermally-sensitive member is only heated directly
• CPC Class Codes: H01L 23/3735 : Laminates or multilayers, e.g. direct bond copper ceramic substrates
• CPC Class Codes: H01L 23/522 : including external interconnections consisting of a multilayer structure of conductive and insulating layers inseparably formed on the semiconductor body
• CPC Class Codes: H01L 27/1203 : the substrate comprising an insulating body on a semiconductor body, e.g. SOI three-dimensional layout H01L27/0688
• CPC Class Codes: H01L 2924/00 : Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
• CPC Class Codes: H01L 2924/0002 : Not covered by any one of groups H01L24/00, H01L24/00 and H01L2224/00
• CPC Class Codes: H01L 2924/09701 : Low temperature co-fired ceramic [LTCC]
• CPC Class Codes: H02N 1/006 : of the gap-closing type H02N1/004 takes precedence
• CPC Class Codes: H02N 10/00 : Electric motors using thermal effects motors using expansion or contraction of bodies due to heating or cooling F03G7/06
• CPC Class Codes: Y10T 29/49222 : forming array of contacts or terminals

Abstract

MEMS Device Having A Trilayered Beam And Related Methods. According to one embodiment, a movable, trilayered microcomponent suspended over a substrate is provided and includes a first electrically conductive layer patterned to define a movable electrode. The first metal layer is separated from the substrate by a gap. The microcomponent further includes a dielectric layer formed on the first metal layer and having an end fixed with respect to the substrate. Furthermore, the microcomponent includes a second electrically conductive layer formed on the dielectric layer and patterned to define an electrode interconnect for electrically communicating with the movable electrode.

Claims

1. A movable, trilayered microcomponent suspended over a substrate, the microcomponent comprising:

(a) a first electrically conductive layer patterned to define a movable electrode, the first electrically conductive layer separated from a substrate by a gap;

(b) a dielectric layer formed on the first electrically conductive layer and including at least one end fixed with respect to the substrate; and

(c) a second electrically conductive layer formed on the dielectric layer and patterned to define an electrode interconnect connected to the movable electrode for electrical communication.

2. The microcomponent of claim 1 wherein the first electrically conductive layer and the second electrically conductive layer have substantially equal respective coefficients of thermal expansion.

3. The microcomponent of claim 1 wherein the first electrically conductive layer comprises a metal material.

4. The microcomponent of claim 1 wherein the first electrically conductive layer comprises a semiconductive material.

5. The microcomponent of claim 1 wherein the movable electrode substantially covers a bottom surface of the dielectric layer.

6. The microcomponent of claim 1 wherein the dielectric layer has a second end freely suspended with respect to the substrate.

7. The microcomponent of claim 1 wherein the second metal layer comprises a metal material.

8. The microcomponent of claim 1 wherein the second metal layer comprises a semiconductive material.

9. The microcomponent of claim 1 wherein the electrode interconnect substantially covers a top surface of the dielectric layer.

10. The microcomponent of claim 1 wherein the dielectric layer comprises a nonconductive, resilient material.

11. An actuator having a movable, trilayered microcomponent, the actuator comprising:

(a) a stationary electrode;

(b) a resilient structural layer including at least one end fixed with respect to the stationary electrode, a bottom surface suspended over the stationary electrode, and a top surface;

(c) a movable electrode attached to the bottom surface of the resilient structural layer whereby the movable electrode is separated from the stationary electrode by a gap; and

(d) an electrode interconnect attached to the top surface of the structural layer and connected to the movable electrode for electrical communication.

12. The actuator of claim 11 wherein the stationary electrode is attached to a substrate.

13. The actuator of claim 11 wherein the movable electrode and the stationary electrode have substantially equal respective coefficients of thermal expansion.

14. The actuator of claim 11 wherein the stationary electrode comprises a metal material.

15. The actuator of claim 11 wherein the stationary electrode comprises a semiconductive material.

16. The actuator of claim 11 wherein the movable electrode substantially covers the bottom surface of the resilient structural layer.

17. The actuator of claim 11 wherein the movable electrode comprises a metal material.

18. The actuator of claim 11 wherein the movable electrode comprises a semiconductive material.

19. The actuator of claim 11 wherein the resilient structural layer has a second end freely suspended with respect to the substrate.

20. The actuator of claim 11 wherein the electrode interconnect substantially covers the top surface of the resilient structural layer.

21. The actuator of claim 11 wherein the movable electrode and electrode interconnect are dimensioned substantially equal to and aligned with one another on opposing surfaces of the resilient structural layer.

22. The actuator of claim 11 wherein the resilient structural layer comprises a nonconductive material.

23. A microscale, electrostatically actuated switch having a movable, trilayered microcomponent, the switch comprising:

(a) a substrate including a stationary electrode and a stationary contact attached thereto;

(b) a resilient structural layer including at least one end fixed with respect to the substrate, a bottom surface suspended over the substrate, and a top surface opposing the bottom surface;

(c) a movable electrode attached to the bottom surface of the resilient structural layer whereby the movable electrode is separated from the stationary electrode by a first gap;

(e) an electrode interconnect attached to the top surface of the resilient structural layer and connected to the movable electrode for electrical communication;

(f) a movable contact attached to the bottom surface of the structural layer whereby the movable contact is separated from the stationary contact by a second gap; and

(g) a contact interconnect formed on the top surface of the structural layer and connected to the movable contact for electrical communication.

24. The switch of claim 23 wherein the movable electrode and the electrode interconnect have substantially equal respective coefficients of thermal expansion.

25. The switch of claim 23 wherein the movable contact and the contact interconnect have substantially equal respective coefficients of thermal expansion.

26. The switch of claim 23 wherein the stationary electrode comprises a metal material.

27. The switch of claim 23 wherein the movable electrode substantially covers the bottom surface of the resilient structural layer.

28. The switch of claim 23 wherein the electrode interconnect substantially covers the top surface of the resilient structural layer.

29. The switch of claim 23 wherein the movable electrode and electrode interconnect are dimensioned substantially equal to and aligned with one another on opposing surfaces of the resilient structural layer.

30. The switch of claim 23 wherein the movable contact is positioned adjacent the at least one end.

31. The switch of claim 30 wherein the movable electrode substantially covers an area of the bottom surface surrounding the movable contact.

32. The switch of claim 31 wherein the movable electrode and electrode interconnect are dimensioned substantially equal to and aligned with one another on opposing surfaces of the resilient structural layer.

33. The switch of claim 32 wherein the movable contact and contact interconnect are dimensioned substantially equal to and aligned with one another on opposing surfaces of the resilient structural layer.

34. The switch of claim 23 wherein the dielectric layer has a second end freely suspended with respect to the substrate.

35. The switch of claim 23 wherein the second metal layer comprises a metal material.

36. The switch of claim 23 wherein the electrode interconnect extends substantially the area of a second surface of the dielectric layer.

37. The switch of claim 23 wherein the resilient dielectric layer comprises a nonconductive material.

38. The switch of claim 23 wherein the resilient dielectric layer further includes a narrowed portion connecting the electrode interconnect and movable electrode with the contact interconnect and movable contact.

39. The switch of claim 23 wherein the contact interconnect further includes a contact route extending to the at least one end for connecting to an electrical device.

40. The switch of claim 23 wherein the contact interconnect further includes a first and second contact route extending to the at least one end for connecting to an electrical device, whereby the contact routes extend on opposing sides of the electrode interconnect.

41. The switch of claim 23 wherein the movable contact further includes a contact route extending to the at least one end for connecting to an electrical device.

42. The switch of claim 41 wherein the contact interconnect further includes a contact route extending to the at least one end for connecting to the electrical device.

44. The switch of claim 37 wherein the first and second movable electrodes and the first and second electrode interconnects have substantially equal respective coefficients of thermal expansion.

45. The switch of claim 37 wherein the resilient structural layer further includes a first flexure connecting the first portion to the third portion and a second flexure connecting the second portion to the third portion.

43. A microscale, electrostatically actuated switch having a movable, trilayered component, the switch comprising:

(a) a substrate including a first and second stationary electrode and a stationary contact attached thereto, wherein the stationary contact is positioned between the first and second stationary electrodes;

(b) a resilient structural layer including a first and second end fixed with respect to the substrate and including first, second, and third portions including top and bottom surfaces, the bottom surfaces suspended over the substrate;

(c) a first movable electrode attached to the bottom surface of the first portion and suspended over the first stationary electrode;

(d) a first electrode interconnect attached to the top surface of the first portion and electrically connected to the first movable electrode;

(e) a second movable electrode attached to the bottom surface of the second portion and suspended over the second stationary electrode;

(f) a second electrode interconnect attached to the top surface of the second portion and electrically connected to the second movable electrode;

(g) a movable contact attached to the bottom surface of the third portion and suspended over the stationary contact; and

(h) a contact interconnect attached to the top surface of the third portion and electrically connected to the movable contact.

46. A microscale, electrostatically actuated switch having a movable, trilayered microcomponent, the switch comprising:

(a) a substrate including a stationary electrode and a stationary contact attached thereto;

(b) a resilient structural layer including at least one end fixed with respect to the substrate, a bottom surface suspended over the substrate, and a top surface opposing the bottom surface;

(c) a movable electrode attached to the bottom surface of the resilient structural layer whereby the movable electrode is separated from the stationary electrode by a gap;

(d) a movable contact attached to the bottom surface of the structural layer whereby the movable contact is separated from the stationary contact by a gap; and

(e) a contact interconnect formed on the top surface of the structural layer, connected to the movable contact for electrical communication, and dimensioned substantially equal to and aligned with movable contact and movable electrode.

47. The switch of claim 46 wherein the movable contact and the contact interconnect have substantially equal respective coefficients of thermal expansion.

48. The switch of claim 46 wherein the contact interconnect includes an electrode portion that is dimensioned substantially equal to and aligned with movable electrode.

49. The switch of claim 46 wherein the contact interconnect includes a contact portion that is dimensioned substantially equal to and aligned with movable contact.

50. The switch of claim 46 wherein the contact interconnect further includes an electrode portion that is dimensioned substantially equal to and aligned with movable electrode and a connect route for electrically connecting the electrode portion and the contact portion.

51. A method of implementing an actuation function in an actuator having a movable, trilayered microcomponent, comprising:

(a) providing an actuator having a movable, trilayered microcomponent, the actuator comprising;

(i) a stationary electrode;

(ii) a resilient structural layer including at least one end fixed with respect to the stationary electrode, a bottom surface suspended over the stationary electrode, and a top surface;

(iii) a movable electrode attached to the bottom surface of the resilient structural layer whereby the movable electrode is separated from the stationary electrode by a gap; and

(iv) an electrode interconnect attached to the top surface of the structural layer and electrically connected to the movable electrode for electrically communicating with the movable electrode; and

(b) applying a voltage between the electrode interconnect and the stationary electrode to electrostatically couple the movable electrode with the stationary electrode across the gap, whereby the resilient structural layer is deflected toward the substrate.