Integrated nanotube and field effect switching devices
View Patent ↗Hybrid switching devices integrate nanotube switching elements with field effect devices, such as NFETs and PFETs. A switching device forms and unforms a conductive channel from the signal input to the output subject to the relative state of the control input. In embodiments of the invention, the conductive channel includes a nanotube channel element and a field modulatable semiconductor channel element. The switching device may include a nanotube switching element and a field effect device electrically disposed in series. According to one aspect of the invention, an integrated switching device is a four-terminal device with a signal input terminal, a control input terminal, a second input terminal, and an output terminal. The devices may be non-volatile. The devices can form the basis for a hybrid NT-FET logic family and can be used to implement any Boolean logic circuit.
1. A nonvolatile switching device comprising:
an input terminal able to receive an input signal;
an output terminal in electrical communication with a circuit to be controlled;
a control structure, electrical stimulation of the control structure controlling the formation of an electrically conductive channel between the signal input terminal and the output terminal, a first portion of the electrically conductive channel including a nanotube channel element and a second portion of the electrically conductive channel including a field modulatable semiconductor channel element;
wherein the formation of the electrically conductive channel allows propagation of the input signal to the output.
2. The nonvolatile switching device of claim 1 , wherein a first control terminal of the control structure carries a first electrical signal and a second control terminal of the control structure carries a second electrical signal, the second electrical signal comprising the logical complement of the first electrical signal.
3. The nonvolatile switching device of claim 2 , wherein the electrically conductive channel is formed and the circuit to be controlled is responsive to electrical stimulus on the input terminal.
4. The nonvolatile switching device of claim 2 , wherein the input terminal comprises a power supply.
5. The nonvolatile switching device of claim 4 , wherein the electrically conductive channel is unformed and the circuit to be controlled is disconnected from the power supply.
6. The nonvolatile switching device of claim 1 , wherein the control structure comprises a first terminal carrying a first electrical signal and a second terminal carrying a second electrical signal, the second electrical signal approximately equal to the first electrical signal.
7. The nonvolatile switching device of claim 6 , wherein when the electrically conductive channel is formed, said channel is nonvolatilely preserved and unresponsive to electrical stimulus at the input terminal.
8. The nonvolatile switching device of claim 7 , wherein the input terminal comprises a power supply and wherein the circuit to be controlled is connected to the power supply.
9. The nonvolatile switching device of claim 6 , wherein when the electrically conductive channel is unformed, said channel is nonvolatilely preserved and unresponsive to electrical stimulus at the input terminal.
10. The nonvolatile switching device of claim 9 , wherein the input terminal comprises a power supply and wherein the circuit to be controlled is disconnected from the power supply.
11. The nonvolatile switching device of claim 1 , wherein the circuit to be controlled comprises a CMOS circuit.
12. The nonvolatile switching device of claim 1 , where the nanotube channel element comprises an electromechanically deflectable nanotube article in electrical communication with the input terminal, the nanotube article having a first and a second positional state controllably induced by the control structure.
13. The nonvolatile switching device of claim 1 , wherein the field modulatable semiconductor channel element comprises one of a PFET and a NFET.
14. The nonvolatile switching device of claim 1 , wherein the field modulatable semiconductor channel element includes a gate region, a source region, a drain region and a channel region disposed between the source region and the drain region, electrically responsive to the gate region.
15. The nonvolatile switching device of claim 14 , wherein the nanotube channel element is in electrical communication with the source region of the field modulatable semiconductor channel element.
16. The nonvolatile switching device of claim 14 , wherein the gate region of the field modulatable semiconductor channel element is in electrical communication with one of a first and a second terminal of the control structure.
17. The nonvolatile switching device of claim 1 wherein the first portion of the electrically conductive channel is formed in response to a first threshold voltage and the second portion of the electrically conductive channel is formed in response to a second threshold voltage, the first threshold voltage being greater than the second threshold voltage.