PIEZOELECTRIC ELECTROMECHANICAL DEVICES

• US 20130038383A1
• Filed: 08/12/2011
• Published: 02/14/2013
• Est. Priority Date: 08/12/2011
• Status: Active Grant

• Current Assignee: Massachusetts Institute of Technology
• Original Assignee: Massachusetts Institute of Technology
• Inventors: Weinstein, Dana, Marathe, Radhika
• Granted Patent: US 8,841,818 B2
• Time in Patent Office: Days
• US Class Current: 327/537
• CPC Class Codes: H01L 29/517 the insulating material comprising a metallic compound, e.g. metal oxide, metal silicate H01L29/518 takes precedence
• CPC Class Codes: H01L 29/518 the insulating material containing nitrogen, e.g. nitride, oxynitride, nitrogen-doped material
• CPC Class Codes: H01L 29/7842 means for exerting mechanical stress on the crystal lattice of the channel region, e.g. using a flexible substrate variation of the composition of the channel H01L29/1054
• CPC Class Codes: H01L 29/84 controllable by variation of applied mechanical force, e.g. of pressure
• CPC Class Codes: H10N 30/206 using only longitudinal or thickness displacement, e.g. d33 or d31 type devices
• CPC Class Codes: H10N 30/302 Sensors

Abstract

An piezoelectric electromechanical transistor has first and second terminals formed in a semiconductor region, a gate and a piezoelectric region between the gate and the semiconductor region. The piezoelectric region may be configured to drive the semiconductor region to vibrate in response to a signal applied to the gate. The transistor may be configured to produce a signal at the first terminal at least partially based on vibration of the semiconductor region.

Claims

1. A piezoelectric electromechanical transistor, comprising:

a semiconductor region in which are formed first and second terminals of the piezoelectric electromechanical transistor;

a gate; and

a piezoelectric region between the gate and the semiconductor region, wherein the piezoelectric region is configured to induce a change in strain of the semiconductor region in response to a signal applied to the gate.

2. The piezoelectric electromechanical transistor of claim 1, wherein the first terminal comprises a source region and the second terminal comprises a drain region.

3. The piezoelectric electromechanical transistor of claim 2, wherein the semiconductor region comprises a region between the source region and the drain region having a doping different from that of the source region and the drain region.

4. The piezoelectric electromechanical transistor of claim 1, wherein the semiconductor region comprises silicon.

5. The piezoelectric electromechanical transistor of claim 1, wherein the gate comprises a metal or a semiconductor.

6. The piezoelectric electromechanical transistor of claim 1, wherein the piezoelectric region is formed on a sidewall of the semiconductor region.

7. The piezoelectric electromechanical transistor of claim 1, wherein the piezoelectric region contacts the gate and the semiconductor region.

8. The piezoelectric electromechanical transistor of claim 1, wherein the piezoelectric region comprises aluminum nitride.

9. The piezoelectric electromechanical transistor of claim 1, wherein the gate is a first gate and the piezoelectric electromechanical transistor further comprises a second gate.

10. The piezoelectric electromechanical transistor of claim 9, further comprising:

a second piezoelectric region between the semiconductor region and the second gate.

11. The piezoelectric electromechanical transistor of claim 1, wherein the piezoelectric electromechanical transistor is configured to vibrate in response to the signal applied to the gate.

12. The piezoelectric electromechanical transistor of claim 1, wherein the piezoelectric electromechanical transistor is configured to vibrate in a bulk acoustic wave mode of vibration.

13. The piezoelectric electromechanical transistor of claim 1, wherein the piezoelectric electromechanical transistor is configured to vibrate in a flexural mode, a breathing mode, a wine glass mode, and/or a shear mode of vibration.

14. The piezoelectric electromechanical transistor of claim 1, wherein the semiconductor region has a cuboid shape.

15. The piezoelectric electromechanical transistor of claim 1, wherein the piezoelectric electromechanical transistor is configured to vibrate along a direction perpendicular to a direction of current flow in the semiconductor region.

16. The piezoelectric electromechanical transistor of claim 1, wherein the gate drives the piezoelectric electromechanical transistor to resonate at a frequency of at least 100 MHz.

17. The piezoelectric electromechanical transistor of claim 1, wherein the gate is biased at a DC bias voltage.

18. A piezoelectric electromechanical transistor, comprising:

a semiconductor region in which are formed first and second terminals of the piezoelectric electromechanical transistor;

a gate; and

a piezoelectric region between the gate and the semiconductor region,

wherein a signal is produced at the first terminal at least partially based on a change in strain of the semiconductor region.

19. The piezoelectric electromechanical transistor of claim 18, wherein the first terminal comprises a source region and the second terminal comprises a drain region.

20. The piezoelectric electromechanical transistor of claim 19, wherein the semiconductor region comprises an region between the source region and the drain region having a doping different from that of the source region and the drain region.

21. The piezoelectric electromechanical transistor of claim 18, wherein the semiconductor region comprises silicon.

22. The piezoelectric electromechanical transistor of claim 18, wherein the gate comprises a metal or a semiconductor.

23. The piezoelectric electromechanical transistor of claim 18, wherein the piezoelectric region is formed on a sidewall of the semiconductor region.

24. The piezoelectric electromechanical transistor of claim 18, wherein the piezoelectric region contacts the gate and the semiconductor region.

25. The piezoelectric electromechanical transistor of claim 18, wherein the piezoelectric region comprises aluminum nitride.

26. The piezoelectric electromechanical transistor of claim 18, wherein the semiconductor region has a cuboid shape.

27. The piezoelectric electromechanical transistor of claim 18, wherein the piezoelectric electromechanical transistor is configured to resonate at a frequency of at least 100 MHz.

28. A method, comprising:

providing a first signal to a gate of a transistor to induce a change in strain of a semiconductor region using the piezoelectric effect; and

receiving a second signal from the semiconductor region produced by the transistor.

29. The method of claim 28, wherein the gate is a first gate, and the method further comprises:

biasing the first gate using a first DC voltage; and

biasing a second gate of the transistor using a second DC voltage.

30. The method of claim 28, wherein the second signal is received from a drain region formed in the semiconductor region.

31. The method of claim 28, wherein providing the first signal induces vibration of the semiconductor region.

32. A piezoelectric electromechanical device, comprising:

a first gate;

a first piezoelectric region;

a first region;

a second piezoelectric region; and

a second gate,

wherein the first piezoelectric region is configured to induce the piezoelectric electromechanical device to vibrate in response to a signal applied to the first gate.

33. The piezoelectric electromechanical device of claim 32, wherein the first piezoelectric region is between the first gate and the first region, and the second piezoelectric region is between the second gate and the first region.