Nonvolatile nanotube switch elements using sidewall contacts
Under one aspect, a non-volatile nanotube diode device includes first and second terminals; a semiconductor element including a cathode and an anode, and capable of forming a conductive pathway between the cathode and anode in response to electrical stimulus applied to the first conductive terminal; and a nanotube switching element including a nanotube fabric article in electrical communication with the semiconductive element, the nanotube fabric article disposed between and capable of forming a conductive pathway between the semiconductor element and the second terminal, wherein electrical stimuli on the first and second terminals causes a plurality of logic states.
1. A non-volatile nanotube switch, comprising:
a first conductive terminal, said first conductive terminal having a top surface and a sidewall surface;
a first protective insulator positioned over said first conductive terminal;
a nanotube element positioned over said insulator, said nanotube element a top surface, a bottom surface, a first sidewall surface, and a second sidewall surface;
a second protective insulator positioned over said nanotube element;
a second conductive terminal positioned over said second protective insulator, said second conductive terminal having a bottom surface and a sidewall surface;
a first vertical conductive structure providing electrical communication between said sidewall surface of said first conductive terminal and said first sidewall surface of said nanotube element;
a second vertical conductive structure providing electrical communication between said sidewall surface of said second conductive terminal and said second sidewall surface of said nanotube element; and
control circuitry in electrical communication with and capable of applying electrical stimulus to the first and second conductive terminals;
wherein said first vertical conductive structure and said second vertical conductive structure are electrically isolated from each other;
wherein said first protective insulator layer prevents said top surface of said first conductive layer from being in direct physical contact with said bottom surface of said nanotube element;
wherein said second protective insulator layer prevents said bottom surface of said second conductive terminal from being in physical contact with said top surface of said nanotube element; and
wherein said nanotube element is capable of switching between a plurality of different resistance states corresponding to a plurality of different electronic states.
2. The non-volatile nanotube switch of claim 1 wherein said first conductive terminal is a first device terminal and said second conductive layer is a second device terminal.
3. The non-volatile nanotube switch of claim 1 wherein for each different electronic state of said plurality of electronic states, said nanotube element provides an electrical pathway of corresponding different resistance between said first nanotube element sidewall surface and said second nanotube element sidewall surface.
4. The non-volatile nanotube switch of claim 1 wherein said control circuitry includes a semiconductor field effect transistor in contact with said first conductive terminal.
5. The non-volatile nanotube switch of claim 1 wherein said first and second conductive layers and said nanotube element each have a substantially circular lateral shape.
6. The non-volatile nanotube switch of claim 1 wherein said first and second conductive terminals and said nanotube element each have a substantially rectangular lateral shape.
7. The non-volatile nanotube switch of claim 1 wherein said first and second conductive terminals and said nanotube element each have a lateral dimension between about 200 nm and about 22 nm.
8. The non-volatile nanotube switch of claim 1 wherein said first and second conductive terminals and said nanotube element each have a lateral dimension between about 22 nm and about 10 nm.
9. The non-volatile nanotube switch of claim 1 wherein said first and second conductive terminals and said nanotube element each have a lateral dimension of less than about 10 nm.
10. The non-volatile nanotube switch of claim 1 wherein said nanotube element is a nanotube fabric.
11. The non-volatile nanotube switch of claim 10 wherein said nanotube fabric has a thickness between about 0.5 nm and about 10 nm.
12. The non-volatile nanotube switch of claim 10 wherein said nanotube fabric has a thickness between about 10 nm and about 50 nm.
13. The non-volatile nanotube switch of claim 10 wherein said nanotube fabric is a single layer nanotube fabric.
14. The non-volatile nanotube switch of claim 1 wherein the first and second conductive layers each comprise a conductive material independently selected from the group consisting of Ru, Ti, Cr, Al, Al(Cu), Au, Pd, Pt, Ni, Ta, W, Cu, Mo, Ag, In, Ir, Pb, Sn, TiAu, TiCu, TiPd, PbIn, TiW, RuN, RuO, TiN, TaN, CoSix, and TiSix.