MEMS switches with reduced switching voltage and methods of manufacture

Patent metadata

Field	Value
Publication number	US-9019049-B2
Application number	US-201313826070-A
Country	US
Kind code	B2
Filing date	Mar 14, 2013
Priority date	Apr 22, 2008
Publication date	Apr 28, 2015
Grant date	Apr 28, 2015

Abstract

MEMS switches and methods of manufacturing MEMS switches is provided. The MEMS switch having at least two cantilevered electrodes having ends which overlap and which are structured and operable to contact one another upon an application of a voltage by at least one fixed electrode.

First claim

It is claimed:

1. A structure comprising:
at least two fixed electrodes including a first fixed electrode and a second fixed electrode; and
at least two cantilevered electrodes of different lengths having ends which overlap,
wherein:
a first cantilevered electrode of the at least two cantilevered electrodes is a first length such that an arm of the first cantilevered electrode of the at least two cantilevered electrodes extends horizontally over the at least two fixed electrodes;
a second cantilevered electrode of the at least two cantilevered electrodes is a second length such that an arm of the second cantilevered electrode of the at least two cantilevered electrodes extends horizontally over only one of the at least two fixed electrodes and overlaps a portion the first cantilevered electrode of the at least two cantilevered electrodes, wherein the arm of the first cantilevered electrode is longer than the arm of the second cantilevered electrode;
bases of the at least two cantilevered electrodes and the at least two fixed electrodes are formed directly on surface of a dielectric layer;
an end of the first cantilevered electrode extends toward a base of the second cantilevered electrode;
an end of the second cantilevered electrode extends toward a base of the first cantilevered electrode; and
the first of the at least two cantilevered electrodes is structured and configured to contact the second fixed electrode upon an application of a voltage by at least the first fixed electrode.

2. The structure of claim 1 , further comprising a hermetically sealed volume having encapsulated therein the at least two cantilevered electrodes and the at least two fixed electrodes, wherein the hermetically sealed volume is provided by at least a liner.

3. The structure of claim 2 , wherein:
the first cantilevered electrode of the at least two cantilevered electrodes is a moveable electrode;
the second cantilevered electrode of the at least two cantilevered electrodes is a stationary electrode; and
the stationary electrode is fixed to the liner such that the stationary electrode remains stationary upon the application of the voltage by at least the first fixed electrode.

4. The structure of claim 3 , wherein:
the voltage provided by the first fixed electrode is a positive voltage;
the stationary electrode is structured and configured to apply a negative voltage;
the moveable electrode is positioned between the second fixed electrode and the stationary electrode; and
the moveable electrode is structured and configured to move away from the stationary electrode and toward the first fixed electrode and to contact with the second fixed electrode upon the application of the positive voltage and the negative voltage.

5. The structure of claim 3 , wherein the first fixed electrode and the second fixed electrode are aligned vertically under the moveable electrode.

6. The structure of claim 5 , wherein the second fixed electrode is aligned vertically under the stationary electrode.

7. The structure of claim 3 , wherein the liner of the hermetically sealed volume is a nitride layer.

8. The structure of claim 7 , wherein the nitride layer is formed directly on an upper surface of the stationary electrode.

9. The structure of claim 1 , wherein:
the first cantilevered electrode of the at least two cantilevered electrodes is a moveable electrode;
the second cantilevered electrode of the at least two cantilevered electrodes is a stationary electrode; and
the stationary electrode is fixed to the liner such that the stationary electrode remains stationary upon the application of the voltage by at least the first fixed electrode;
the first fixed electrode is only aligned vertically under the moveable electrode;
the second fixed electrode is aligned vertically under the stationary electrode and the moveable electrode; and
the liner of the hermetically sealed volume is a nitride layer.

10. The structure of claim 1 , wherein arms of the at least two cantilever electrodes are free floating.

11. The structure of claim 1 , wherein the first fixed electrode and the second fixed electrode are vertically aligned under an arm of the first cantilever electrode of the at least two cantilever electrodes.

12. The structure of claim 11 , wherein:
the second fixed electrode is vertically aligned under an arm of the second cantilever electrode of the at least two cantilever electrodes; and
the first cantilever electrode is spaced within a cavity between the second cantilever electrode and the second fixed electrode.

13. The structure of claim 9 , wherein the end of the stationary electrode is unattached to the liner.

14. The structure of claim 1 , further comprising a plurality of metal filled vias extending vertically into the dielectric layer, wherein the bases of the at least two cantilevered electrodes and the at least two fixed electrodes contact the plurality of metal filled vias.

Assignees

• IBM

Inventors

• Luce Stephen E
• Stamper Anthony K

Classifications

• Y10T29/49105

  Switch making · CPC title

• H01H11/00

  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 title

• B81C2201/0145

  Spark erosion · CPC title

• B81C1/0015

  Cantilevers (switches using MEMS H01H1/0036; electrostatic relays using micromechanics H01H59/0009; microelectro-mechanical resonators H03H9/02244) · CPC title

• H01H1/0036

  Switches making use of microelectromechanical systems [MEMS] (for electromagnetic relays H01H50/005; for electrostatic relays H01H59/0009) · CPC title