IP Library Granted Patent US 8,604,670
Granted Patent B2
US 8,604,670 · App. 12/994,301 · Granted Dec 10, 2013

Piezoelectric ALN RF MEM switches monolithically integrated with ALN contour-mode resonators

Inventors: Rashed Mahameed (Umm Al-Fahem, IL); Nipun Sinha (Philadelphia, PA); Gianluca Piazza (Philadelphia, PA)
Assignee: The Trustees of the University of Pennsylvania
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Quick Facts
Patent No.
US 8,604,670
App. No.
12/994,301
Granted
Dec 10, 2013
Kind
B2
Abstract

Piezoelectric switches and methods of forming piezoelectric switches. The piezoelectric switch includes first and second cantilever beam actuators. The second cantilever beam actuator has a projection that overlaps the first cantilever beam actuator in a contact region. The projection is mechanically separated from the first cantilever beam actuator by a nanogap such that the first and second cantilever beam actuators are electrically isolated from each other. Each of the first and second cantilever beam actuators includes a piezoelectric actuation layer.

Claims (44)

1. A piezoelectric switch comprising:

a first cantilever beam actuator which includes a first conductive layer which moves with said first cantilever beam actuator;

a second cantilever beam actuator having a projection that overlaps the first cantilever beam actuator in a contact region, said projection mechanically separated from the first cantilever beam actuator by a nanogap such that the first and second cantilever beam actuators are electrically isolated from each other, said projection includes a second conductive layer;

wherein each of said first and second cantilever beam actuators includes a respective piezoelectric actuation layer, and

wherein electrical current flowing through each piezoelectric actuation layer causes said first conductive layer and said second conductive layer to become electrically conductive with each other.

2. The piezoelectric switch according to claim 1 , wherein at least one piezoelectric actuation layer including a unimorph or a bimorph actuator.

3. The piezoelectric switch according to claim 1 , wherein the nanogap includes multiple nanogaps.

4. The piezoelectric switch according to claim 1 , wherein the first cantilever beam actuator is positioned collinear with the second cantilever beam actuator.

5. The piezoelectric switch according to claim 1 , wherein the first cantilever beam actuator is positioned at an angle relative to the second cantilever beam actuator.

6. The piezoelectric switch according to claim 1 , wherein each piezoelectric actuation layer includes a piezoelectric layer disposed between first and second electrodes.

7. The piezoelectric switch according to claim 6 , wherein at least one of the piezoelectric layer is formed from a material including aluminum nitride, zinc oxide, lead zirconate titanate, gallium arsenide, aluminum gallium arsenide or any combination thereof.

8. The piezoelectric switch according to claim 1 , wherein at least one of the first and second cantilever beam actuators includes a conductor layer disposed proximate to at least one of the piezoelectric actuation layer.

9. The piezoelectric switch according to claim 8 , wherein the conductor layer is disposed on the at least one of the first and second cantilever beam actuators.

10. The piezoelectric switch according to claim 8 , wherein the conductor layer is disposed next to the at least one of the first and second cantilever beam actuators.

11. The piezoelectric switch according to claim 8 , further comprising an isolation layer disposed between the conductor layer and at least one of the piezoelectric actuation layer.

12. The piezoelectric switch according to claim 11 , wherein the isolation layer is formed from a piezoelectric material.

13. The piezoelectric switch according to claim 8 , wherein the second cantilever beam actuator includes the conductor layer and said conductor layer forms the projection.

14. The piezoelectric switch according to claim 13 , including a further conductor layer formed on a portion of the first cantilever beam actuator in a vicinity of the contact region.

15. A semiconductor chip comprising:

the piezoelectric switch according to claim 1 , the piezoelectric switch being coupled to a substrate; and

at least one contour-mode (CM) piezoelectric transducer comprising:

a piezoelectric film being suspended so that it is spaced away from the substrate, and

first and second electrodes disposed on opposite surfaces of said piezoelectric film.

16. A method of forming a piezoelectric switch, the method comprising:

forming a first cantilever beam actuator; and

forming a first conductive layer which moves with said first cantilever beam actuator;

forming a second cantilever beam actuator having a projection that overlaps the first cantilever beam actuator in a contact region, including forming the projection to be mechanically separated from the first cantilever beam actuator by a nanogap such that the first and second cantilever beam actuators are electrically isolated from each other, said projection includes a second conductive layer;

wherein each of the first and second cantilever beam actuators are formed with respective piezoelectric actuation layer, and

wherein electrical current flowing through each piezoelectric actuation layer causes said first conductive layer and said second conductive layer to become electrically conductive with each other.

17. The method according to claim 16 , forming the piezoelectric actuation layer includes:

forming a piezoelectric layer; and

forming first and second electrodes on opposite surfaces of the piezoelectric layer.

18. The method according to claim 16 , including applying a common actuation signal to each of the first and second cantilever beam actuators via the respective piezoelectric actuation layer.

19. The method according to claim 16 , including applying different actuation signals to the first and second cantilever beam actuators via the respective piezoelectric actuation layer.

20. The method according to claim 16 , including:

applying a first actuation signal to the piezoelectric actuation layer of each of the first and second cantilever beam actuators to open the piezoelectric switch; and

applying a second actuation signal to the piezoelectric actuation layer of each of the first and second cantilever beam actuators to close the piezoelectric switch, the second actuation signal having an opposite polarity from the first actuation signal.

21. The method according to claim 16 , including forming a conductor layer proximate to the piezoelectric actuation layer for at least one of the first and second cantilever beam actuators.

22. The method according to claim 21 , including forming the conductor layer on the at least one of the first and second cantilever beam actuators.

23. The method according to claim 21 , including forming the conductor layer next to the at least one of the first and second cantilever beam actuators.

24. The method according to claim 21 , including forming an isolation layer between the conductor layer and the piezoelectric actuation layer to electrically isolate the conductor layer from at least one of the piezoelectric actuation layer.

25. The method according to claim 21 , forming a further conductor layer on a portion of one of the cantilever beam actuators in a vicinity of the contact region.

26. The method according to claim 21 , including forming the piezoelectric switch coupled to a substrate of a semiconductor chip,

wherein the semiconductor chip includes at least one contour-mode piezoelectric transducer.

Assignments (1)
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Mar 22, 2011
From: MAHAMEED, RASHED; SINHA, NIPUN; PIAZZA, GIANLUCA
To: THE TRUSTEES OF THE UNIVERSITY OF PENNSYLVANIA
Reel/Frame 025996/0177 →
Continuity (2)
Provisional Application 61057538 · May 30, 2008
Related Publication 20110181150A1 · Jul 28, 2011