Non-volatile electromechanical field effect devices and circuits using same and methods of forming same
View Patent ↗Under one aspect, a field effect device includes a gate, a source, and a drain, with a conductive channel between the source and the drain; and a nanotube switch having a corresponding control terminal, said nanotube switch being positioned to control electrical conduction through said conductive channel. Under another aspect, a field effect device includes a gate having a corresponding gate terminal; a source having a corresponding source terminal; a drain having a corresponding drain terminal; a control terminal; and a nanotube switching element positioned between one of the gate, source, and drain and its corresponding terminal and switchable, in response to electrical stimuli at the control terminal and at least one of the gate, source, and drain terminals, between a first non-volatile state that enables current flow between the source and the drain and a second non-volatile state that disables current flow between the source and the drain.
1. A field effect device, comprising:
a gate, a source, and a drain, with a conductive channel between the source and the drain; and
a nanotube switch having a corresponding control terminal, said nanotube switch being positioned to control electrical conduction through said conductive channel.
2. The field effect device of claim 1 , wherein the nanotube switch is switchable between a first nonvolatile logical state in which electrical conduction through said conductive channel is enabled, and a second nonvolatile logical state in which electrical conduction through said conductive channel is disabled.
3. The field effect device of claim 2 , wherein the first nonvolatile logical state comprises the nanotube switch contacting one of the gate, the source, and the drain, and wherein the second nonvolatile logical state comprises the nanotube switch contacting the control terminal.
4. The field effect device of claim 2 , wherein the first nonvolatile state comprises the nanotube switch contacting a terminal corresponding to one of the gate, the source, and the drain, and wherein the second nonvolatile logical state comprises the nanotube switch contacting the control terminal.
5. The field effect device of claim 1 , wherein the nanotube switch comprises a non-woven nanotube fabric.
6. The field effect device of claim 1 , wherein the gate, source, drain, and conductive channel are parts of a semiconductor transistor.
7. The field effect device of claim 1 , wherein the nanotube switch controls conduction through said conductive channel by electromechanical deflection.
8. A field effect device, comprising:
a gate having a corresponding gate terminal;
a source having a corresponding source terminal;
a drain having a corresponding drain terminal;
a control terminal;
a nanotube switching element positioned between one of the gate, source, and drain and its corresponding terminal and switchable, in response to electrical stimuli at the control terminal and at least one of the gate, source, and drain terminals, between a first non-volatile state that enables current flow between the source and the drain and a second non-volatile state that disables current flow between the source and the drain.
9. The device of claim 8 wherein the others of the gate, source, and drain are in direct electrical communication with their corresponding terminal.
10. The device of claim 8 , wherein, when the nanotube switching element is in the first state, current flows from the source to the drain in response to electrical stimulus at the gate terminal.
11. The device of claim 8 , wherein, when the nanotube switching element is in the second state, current does not flow from the source to the drain in response to electrical stimulus at the gate terminal.
12. The device of claim 8 , wherein, when the nanotube switching element is in the first state, the nanotube switching element provides a conductive pathway between the one of the gate, source, and drain and its corresponding terminal.
13. The device of claim 8 , wherein, when the nanotube switching element is in the second state, there is no conductive pathway between the one of the gate, source, and drain and its corresponding terminal.
14. The device of claim 8 , further comprising a channel region between the source and the drain through which, when the nanotube switching element is in the first state, current flow is enabled.
15. The device of claim 8 , wherein the gate, source, and drain are parts of a semiconductor transistor.
16. The device of claim 8 , further comprising control logic to switch the nanotube switching element from the first state to the second state by creating a voltage difference between the nanotube switching element and the control terminal and thus causing the nanotube switching element to electrically contact the control terminal.
17. The device of claim 16 , wherein the voltage difference exceeds a threshold voltage below which the nanotube element would remain in the first state.
18. The device of claim 8 , further comprising control logic to switch the nanotube switching element from the first state to the second state by creating a voltage difference between the nanotube switching element and the control terminal and thus causing the nanotube switching element to electrically contact an insulating layer on the control terminal.
19. The device of claim 18 , wherein the voltage difference exceeds a threshold voltage below which the nanotube element would remain in the first state.
20. The device of claim 8 , further comprising control logic to switch the nanotube switching element from the second state to the first state by creating a voltage difference between the nanotube switching element and the control terminal and thus cause the nanotube switching element to electrically contact the one of the gate, source, and drain.
21. The device of claim 20 , wherein the voltage difference exceeds a threshold voltage below which the nanotube element would remain in the first state.
22. The device of claim 8 , further comprising control logic to switch the nanotube switching element from the second state to the first state by creating a voltage difference between the nanotube switching element and the control terminal and thus cause the nanotube switching element to electrically contact the one of the gate, source, and drain terminals.
23. The device of claim 22 , wherein the voltage difference exceeds a threshold voltage below which the nanotube element would remain in the first state.
24. The device of claim 8 , wherein switching the nanotube switching element between the first and second states electromechanically deflects the nanotube switching element.
25. The device of claim 8 , wherein the nanotube switching element comprises a nonwoven nanotube fabric.
26. The device of claim 8 , further comprising readout circuitry capable of determining whether the nanotube switching element is in the first state or the second state.
27. The device of claim 26 , wherein, when the readout circuitry determines whether the nanotube switching element is in the first state or the second state, the readout circuitry does not change the state of the nanotube switching element.
28. The device of claim 8 , wherein the gate terminal is connected to a word line, the source terminal is connected to a bit line, the drain terminal is connected to a release line, and the control terminal is connected to a reference line.