Logic circuits using carbon nanotube transistors
In accordance with some embodiments, logical circuits comprising carbon nanotube field effect transistors are disclosed herein.
1. An integrated circuit, comprising:
first and second CNTFETs coupled in series between high and low supply references, the first CNTFET having a top gate to provide a logical input to receive High and Low logical values, the second CNTFET having a top gate coupled to a bias supply so that the second CNTFET provides an active load for the first CNTFET to provide suitable logical High and Low output levels.
2. The integrated circuit of claim 1 , in which the level of the low supply reference is below a logical Low level.
3. The integrated circuit of claim 2 , in which the first and second CNTFETs constitute an inverter gate.
4. The integrated circuit of claim 3 , in which the first and second CNTFETs conduct holes stronger than electrons.
5. The integrated circuit of claim 4 , in which the first CNTFET is biased to conduct holes, and the second CNTFET is biased to conduct electrons, wherein the first CNTFET is stronger than the second CNTFET.
6. The integrated circuit of claim 5 , in which the first and second CNTFETs comprise drain and source electrodes formed from a material with a Fermi energy level that is closer to a valence band than to a conduction band.
7. The integrated circuit of claim 5 , in which the first and second CNTFET have channels comprising one or more carbon nanotubes, the first CNTFET channel having more carbon nanotubes than the second CNTFET channel so that the first CNTFET conducts more strongly than the second CNTFET.
8. The integrated circuit of claim 1 , in which the first and second CNTFETs have channels formed from intrinsic carbon nanotubes.
9. An inverter circuit, comprising:
a first CNTFET coupled between a first supply reference and an output node for the inverter circuit; and
a second CNTFET coupled between the output node and a second supply reference, the first CNTFET to provide an input to receive High and Low logical values for the inverter circuit, the second CNTFET biased to provide an active load for the first CNTFET, wherein the second CNTFET is turned on for High and Low output states.
10. The inverter circuit of claim 9 , in which the first supply reference is greater than the second supply reference.
11. The inverter circuit of claim 10 , in which the first and second CNTFETs conduct holes stronger than electrons.
12. The inverter circuit of claim 11 , in which the first CNTFET is biased to conduct holes, and the second CNTFET is biased to conduct electrons, wherein the first CNTFET is stronger than the second CNTFET.
13. The inverter circuit of claim 12 , in which the first and second CNTFETs comprise drain and source electrodes formed from a material with a Fermi energy level that is closer to a valence band than to a conduction band.
14. The inverter circuit of claim 13 , in which the first and second CNTFET have channels comprising one or more carbon nanotubes, the first CNTFET channel having more carbon nanotubes than the second CNTFET channel so that the first CNTFET conducts more strongly than the second CNTFET.
15. The inverter circuit of claim 9 , in which the first and second CNTFETs have channels formed from intrinsic carbon nanotubes.