Memory cell that employs a selectively grown reversible resistance-switching element and methods of forming the same
In some aspects, a memory cell is provided that includes (1) a steering element above a substrate; and (2) a reversible resistance-switching element coupled to the steering element, wherein the reversible resistance-switching element is selectively formed by: (a) forming a material layer on the substrate; (b) etching the material layer; and (c) oxidizing the etched material layer to form a reversible resistance-switching material. Numerous other aspects are provided.
1. A memory cell comprising:
a steering element above a substrate; and
a reversible resistance-switching element coupled to the steering element, wherein the reversible resistance-switching element comprises an etched material layer on the substrate, the etched material layer including a non-oxidized layer of the etched material layer below an oxidized layer of the etched material layer.
2. The memory cell of claim 1 , wherein the material layer comprises one or more of Ta, TaN, Nb, NbN, Al, AlN, Hf, HfN, V, and VN.
3. The memory cell of claim 1 , wherein the reversible resistance-switching material comprises one or more of Ta 2 O 5 , Nb 2 O 5 , Al 2 O 3 , HfO 2 , and V 2 O 5 .
4. The memory cell of claim 1 , wherein the steering element comprises a diode.
5. The memory cell of claim 1 , wherein the steering element comprises a polycrystalline diode.
6. The memory cell of claim 1 , wherein the steering element comprises a vertical polycrystalline diode.
7. The memory cell of claim 1 , wherein the steering element comprises a p-n diode or a p-i-n.
8. The memory cell of claim 1 , wherein the reversible resistance-switching element comprises an oxide thickness of about 500 angstroms or less.
9. The memory cell of claim 1 , wherein the reversible resistance-switching element comprises an oxide thickness of about 300 angstroms or less.
10. The memory cell of claim 1 , wherein the steering element and reversible resistance-switching element are coupled in series.
11. A memory cell comprising:
a first conductor above a substrate;
a reversible resistance-switching element above the first conductor, wherein the reversible resistance-switching element comprises an etched material layer on the substrate, the etched material layer including a non-oxidized layer of the etched material layer below an oxidized layer of the etched material layer;
a diode above the first conductor; and
a second conductor above the diode and the reversible resistance-switching element.
12. The memory cell of claim 11 , wherein the material layer comprises one or more of Ta, TaN, Nb, NbN, Al, AlN, Hf, HfN, V, and VN.
13. The memory cell of claim 11 , wherein the reversible resistance-switching material comprises one or more of Ta 2 O 5 , Nb 2 O 5 , Al 2 O 3 , HfO 2 , and V 2 O 5 .
14. The memory cell of claim 11 , wherein the diode comprises a vertical polycrystalline diode.
15. The memory cell of claim 14 , further comprising a silicide, silicide-germanide or germanide region in contact with polycrystalline material of the vertical polycrystalline diode, wherein the polycrystalline material is in a low-resistivity state.
16. The memory cell of claim 11 , wherein the reversible resistance-switching element comprises an oxide thickness of about 500 angstroms or less.
17. The memory cell of claim 11 , wherein the reversible resistance-switching element comprises an oxide thickness of about 300 angstroms or less.
18. The memory cell of claim 11 , wherein the diode and the reversible resistance-switching element are coupled in series.