Memory cell that employs a selectively grown reversible resistance-switching element and methods of forming the same
View Patent ↗In some aspects, a method of forming a memory cell is provided that includes (1) forming a first conductor above a substrate; (2) forming a reversible resistance-switching element above the first conductor using a selective growth process; (3) forming a diode above the first conductor; and (4) forming a second conductor above the diode and the reversible resistance-switching element. Numerous other aspects are provided.
1. A method of forming a memory cell comprising:
forming a steering element above a substrate; and
forming a reversible resistance-switching element coupled to the steering element, wherein the reversible resistance-switching element is formed using a selective growth process comprising forming a Ti-nitride containing layer, etching the titanium nitride containing layer and oxidizing the etched Ti-nitride containing layer.
2. The method of claim 1 wherein forming the steering element comprises forming a diode.
3. The method of claim 1 wherein forming the steering element comprises forming a polycrystalline diode.
4. The method of claim 1 wherein forming the steering element comprises forming a vertical polycrystalline diode.
5. The method of claim 1 wherein forming the steering element comprises forming a vertical polycrystalline diode having polycrystalline material that is in a low-resistivity state.
6. The method of claim 1 wherein forming the steering element comprises forming a p-n diode or a p-i-n.
7. The method of claim 1 wherein forming the steering element comprises forming a thin film transistor.
8. The method of claim 1 wherein forming the steering element comprises forming a thin film, metal oxide semiconductor field effect transistor (MOSFET).
9. The method of claim 1 wherein forming the reversible resistance-switching element comprises forming at least one of TiO, TiO 2 , TiO x and TiO x N y .
10. The method of claim 9 wherein forming the reversible resistance-switching element comprises forming a reversible resistance-switching element having an oxide thickness of about 500 angstroms or less.
11. The method of claim 10 wherein forming the reversible resistance-switching element comprises forming a reversible resistance-switching element having an oxide thickness of about 300 angstroms or less.
12. The method of claim 1 wherein the Ti-containing layer comprises a TiN layer.
13. The method of claim 1 further comprising coupling the steering element and reversible resistance-switching element in series.
14. A memory cell formed using the method of claim 1 .
15. A memory cell formed using the method of claim 9 .
16. A method of forming a memory cell comprising:
forming a first conductor above a substrate;
forming a reversible resistance-switching element above the first conductor, wherein the reversible resistance-switching element is formed using a selective growth process comprising forming a Ti-nitride containing layer, etching the Ti-nitride containing layer, and oxidizing the etched Ti-nitride containing layer;
forming a diode above the first conductor; and
forming a second conductor above the diode and the reversible resistance-switching element.
17. The method of claim 16 wherein forming the diode comprises forming a vertical polycrystalline diode.
18. The method of claim 17 further comprising forming a silicide, silicide-germanide or germanide region in contact with polycrystalline material of the vertical polycrystalline diode so that the polycrystalline material is in a low-resistivity state.
19. The method of claim 16 wherein forming the reversible resistance-switching element comprises selectively forming at least one of TiO, TiO 2 , TiO x and TiO x N y .
20. The method of claim 16 wherein the Ti-containing layer comprises a TiN layer.
21. A memory cell formed using the method of claim 16 .
22. A memory cell formed using the method of claim 19 .
23. A method of forming a memory cell comprising:
forming a first conductor above a substrate;
forming a titanium nitride layer above the first conductor;
selectively forming a reversible resistance-switching element by etching the titanium nitride layer, and oxidizing the etched titanium nitride layer;
forming a vertical polycrystalline diode above the reversible resistance-switching element; and
forming a second conductor above the vertical polycrystalline diode.
24. The method of claim 23 further comprising forming a silicide, silicide-germanide or germanide region in contact with polycrystalline material of the vertical polycrystalline diode so that the polycrystalline material is in a low-resistivity state.
25. The method of claim 23 wherein forming the reversible resistance-switching element comprises selectively forming at least one of TiO, TiO 2 , TiO x and TiO x N y .
26. The method of claim 23 wherein selectively forming the reversible resistance-switching element comprises forming a reversible resistance-switching element having an oxide thickness of about 300 angstroms or less.
27. The method of claim 23 wherein forming the vertical polycrystalline diode comprises forming a vertical polysilicon diode.
28. A memory cell formed using the method of claim 23 .
29. The method of claim 1 wherein forming the reversible resistance-switching element comprises forming at least one of Ta 2 O 5 , Nb 2 O 5 , Al 2 O 3 , HfO 2 , and V 2 O 5 .
30. A method of forming a memory cell, the method comprising:
forming a steering element above a substrate; and
forming a reversible resistance-switching element coupled to the steering element, wherein the reversible resistance-switching element comprises an etched and oxidized Ti-nitride material.