Nonvolatile nanotube diodes and nonvolatile nanotube blocks and systems using same and methods of making same
View Patent ↗Under one aspect, a nonvolatile nanotube diode includes: a substrate; a semiconductor element disposed over the substrate, the semiconductor element having an anode and a cathode and capable of forming an electrically conductive pathway between the anode and the cathode; a nanotube switching element disposed over the semiconductor element, the nanotube switching element including a conductive contact and a nanotube fabric element capable of a plurality of resistance states; and a conductive terminal disposed in spaced relation to the conductive contact, wherein the nanotube fabric element is interposed between and in electrical communication with the conductive contact and the conductive contact is in electrical communication with the cathode, and wherein in response to electrical stimuli applied to the anode and the conductive terminal, the nonvolatile nanotube diode is capable of forming an electrically conductive pathway between the anode and the conductive terminal.
1. A nonvolatile nanotube diode comprising:
a substrate;
a semiconductor element disposed over the substrate, wherein the semiconductor element comprises a cathode disposed over an anode and the semiconductor element is capable of forming an electrically conductive pathway between the anode and the cathode;
a nanotube switching element disposed over the semiconductor element, wherein the nanotube switching element comprises a nanotube fabric element disposed over a conductive contact and the nanotube fabric element exhibits a plurality of resistance states in response to electrical stimuli; and
a conductive terminal disposed over the nanotube switching element;
wherein the nanotube fabric element is in electrical communication with the conductive contact and the conductive contact is in electrical communication with the cathode;
wherein in response to electrical stimuli applied to the anode and the conductive terminal, the nonvolatile nanotube diode is capable of forming an electrically conductive pathway between the anode and the conductive terminal.
2. The nonvolatile nanotube diode of claim 1 , wherein the anode comprises a conductor material and the cathode comprises a semiconductor material.
3. The nonvolatile nanotube diode of claim 2 , wherein the anode material includes at least one of Al, Ag, Au, Ca, Co, Cr, Cu, Fe, Ir, Mg, Mo Na, Ni, Os, Pb, Pd, Pt, Rb, Ru, Ti, W, Zn, CoSi 2 , MoSi 2 , Pd 2 Si, PtSi, RbSi 2 , TiSi 2 , WSi 2 and ZrSi 2 .
4. The nonvolatile nanotube diode of claim 2 , wherein the semiconductor element comprises a Schottky barrier diode.
5. The nonvolatile nanotube diode of claim 1 , further comprising a second conductive terminal interposed between the substrate and the anode, the second conductive terminal in electrical communication with the anode, wherein in response to electrical stimuli at said second conductive terminal and the conductive terminal, the nonvolatile nanotube diode is capable of forming an electrically conductive pathway between said second conductive terminal and the conductive terminal.
6. The nonvolatile nanotube diode of claim 5 , wherein the anode comprises a semiconductor material of a first type and the cathode region comprises a semiconductor material of a second type.
7. The nonvolatile nanotube diode of claim 6 , wherein the semiconductor material of the first type is positively doped, the semiconductor material of the second type is negatively doped, and the semiconductor element forms a PN junction.
8. The nonvolatile nanotube diode of claim 1 , wherein the nanotube fabric element is substantially vertically disposed.
9. The nonvolatile nanotube diode of claim 1 , wherein the nanotube fabric element is substantially horizontally disposed.
10. The nonvolatile nanotube diode of claim 1 , wherein the nanotube fabric element comprises a nonwoven multilayered fabric.
11. The nonvolatile nanotube diode of claim 10 , wherein the nanotube fabric element has a thickness between approximately 20 nm and approximately 200 nm.
12. The nonvolatile nanotube diode of claim 10 , wherein the conductive contact is disposed substantially parallel to a lower surface of the nanotube fabric element and the conductive terminal is disposed substantially parallel to an upper surface of the nanotube fabric element.
13. The nonvolatile nanotube diode of claim 1 , wherein the semiconductor element comprises a field effect transistor.
14. A nonvolatile nanotube diode comprising:
a substrate;
a conductive terminal disposed over the substrate;
a semiconductor element disposed over the conductive terminal, wherein the semiconductor element comprises an anode disposed over a cathode and the semiconductor element is capable of forming an electrically conductive pathway between the cathode and the anode; and
a nanotube switching element disposed over the semiconductor element, wherein the nanotube switching element comprises a conductive contact disposed over a nanotube fabric element and the nanotube fabric element exhibits a plurality of resistance states in response to electrical stimuli,
wherein the nanotube fabric element is in electrical communication with anode and the conductive contact and the cathode is in electrical communication with the conductive terminal; and
wherein in response to electrical stimuli applied to the conductive contact and the conductive terminal, the nonvolatile nanotube diode is capable of forming an electrically conductive pathway between the conductive terminal and the conductive contact.
15. The nonvolatile nanotube diode of claim 14 , wherein the anode comprises a conductor material and the cathode comprises a semiconductor material.
16. The nonvolatile nanotube diode of claim 15 , wherein the anode material includes at least one of Al, Ag, Au, Ca, Co, Cr, Cu, Fe, Ir, Mg, Mo Na, Ni, Os, Pb, Pd, Pt, Rb, Ru, Ti, W, Zn, CoSi 2 , MoSi 2 , Pd 2 Si, PtSi, RbSi 2 , TiSi 2 , WSi 2 and ZrSi 2 .
17. The nonvolatile nanotube diode of claim 15 , wherein the semiconductor element comprises a Schottky barrier diode.
18. The nonvolatile nanotube diode of claim 14 , further comprising a second conductive terminal interposed between and providing an electrically conductive path between the anode and the nonwoven nanotube fabric element.
19. The nonvolatile nanotube diode of claim 18 , wherein the anode comprises a semiconductor material of a first type and the cathode region comprises a semiconductor material of a second type.
20. The nonvolatile nanotube diode of claim 19 , wherein the semiconductor material of the first type is positively doped, the semiconductor material of the second type is negatively doped, and the semiconductor element forms a PN junction.
21. The nonvolatile nanotube diode of claim 14 , wherein the nanotube fabric element is substantially vertically disposed.
22. The nonvolatile nanotube diode of claim 14 , wherein the nanotube fabric element is substantially horizontally disposed.
23. The nonvolatile nanotube diode of claim 14 , wherein the nanotube fabric element comprises a layer of nonwoven nanotubes having a thickness between approximately 0.5 and approximately 20 nanometers.
24. The nonvolatile nanotube diode of claim 14 , wherein the nanotube fabric element comprises a nonwoven multilayered fabric.
25. The nonvolatile nanotube diode of claim 24 , wherein the conductive contact is disposed substantially parallel to a lower surface of the nanotube fabric element and the conductive terminal is disposed substantially parallel to an upper surface of the nanotube fabric element.
26. The nonvolatile nanotube diode of claim 14 , wherein the semiconductor element comprises a field effect transistor.