Memory cells including dielectric materials, memory devices including the memory cells, and methods of forming same

Patent metadata

Field	Value
Publication number	US-9716225-B2
Application number	US-201414476312-A
Country	US
Kind code	B2
Filing date	Sep 3, 2014
Priority date	Sep 3, 2014
Publication date	Jul 25, 2017
Grant date	Jul 25, 2017

Abstract

A memory cell comprising a threshold switching material over a first electrode on a substrate. The memory cell includes a second electrode over the threshold switching material and at least one dielectric material between the threshold switching material and at least one of the first electrode and the second electrode. A memory material overlies the second electrode. The dielectric material may directly contact the threshold switching material and each of the first electrode and the second electrode. Memory cells including only one dielectric material between the threshold switching material and an electrode are disclosed. A memory device including the memory cells and methods of forming the memory cells are also described.

First claim

What is claimed is:

1. A memory cell, comprising:
a threshold switching material comprising amorphous silicon and at least one of carbon, oxygen, or nitrogen between a pair of electrodes, wherein each electrode of the pair of electrodes comprises polysilicon, tungsten, platinum, palladium, tantalum, nickel, tantalum nitride, tungsten nitride, a metal silicide, or combinations thereof;
at least one doped dielectric material between the threshold switching material and at least one electrode of the pair of electrodes, the threshold switching material over the at least one doped dielectric material; and
a memory material adjacent at least one of the electrodes of the pair of electrodes.

2. The memory cell of claim 1 , wherein the each electrode of the pair of electrodes comprises the same material.

3. The memory cell of claim 1 , wherein the at least one doped dielectric material comprises aluminum oxide.

4. The memory cell of claim 1 , wherein the at least one electrode of the pair of electrodes comprises a metal material in contact with the at least one doped dielectric material.

5. The memory cell of claim 1 , further comprising another dielectric material overlying the threshold switching material.

6. The memory cell of claim 1 , further comprising another electrode on a side of the memory material opposite the at least one electrode of the pair of electrodes.

7. The memory cell of claim 1 , wherein the at least one dielectric material between the threshold switching material and at least one electrode of the pair of electrodes is in direct contact with the threshold switching material.

8. A memory cell, comprising:
a threshold switching material over a first electrode comprising carbon on a substrate;
a second electrode over the threshold switching material;
at least one dielectric material between the threshold switching material and at least one of the first electrode or the second electrode, wherein at least a portion of the at least one dielectric material is doped; and
a memory material over the second electrode.

9. The memory cell of claim 8 , wherein the threshold switching material comprises a chalcogenide material.

10. The memory cell of claim 8 , wherein the threshold switching material comprises arsenic, selenium, silicon, and germanium.

11. The memory cell of claim 8 , wherein the at least one dielectric material comprises aluminum oxide, aluminum silicon oxide, strontium oxide, barium oxide, strontium titanium oxide, magnesium oxide, a refractory metal oxide, a refractory metal alloy oxide, or combinations thereof.

12. The memory cell of claim 8 , wherein the at least one dielectric material has a thickness of between about 3 Å and about 50 Å.

13. The memory cell of claim 8 , wherein the at least one dielectric material is between the threshold switching material and the first electrode.

14. The memory cell of claim 8 , wherein the at least one dielectric material is between the threshold switching material and the second electrode.

15. The memory cell of claim 8 , wherein a first dielectric material of the at least one dielectric material is between the threshold switching material and the first electrode and a second dielectric material of the at least one dielectric material is between the threshold switching material and the second electrode.

16. A method of forming a memory cell, the method comprising:
forming a threshold switching material over a first electrode comprising carbon on a substrate;
forming a second electrode over the threshold switching material;
forming a dielectric material between the threshold switching material and at least one of the first electrode or the second electrode;
doping at least a portion of the dielectric material; and
forming a memory material over the second electrode.

17. The method of claim 16 , wherein forming a threshold switching material over a first electrode comprising carbon on a substrate comprises forming the threshold switching material comprising a chalcogenide material over the first electrode.

18. The method of claim 16 , wherein forming a threshold switching material over a first electrode comprising carbon on a substrate comprises forming the threshold switching material without substantially reacting the threshold switching material with the first electrode.

19. The method of claim 16 , wherein forming a second electrode comprises forming the second electrode from the same material as the first electrode.

20. The method of claim 16 , wherein forming a dielectric material between the threshold switching material and at least one of the first electrode or the second electrode comprises at least one of:
forming a first dielectric material between the threshold switching material and the first electrode; and
forming a second dielectric material between the threshold switching material and the second electrode.

21. The method of claim 16 , wherein forming a dielectric material comprises forming between about 3 Å and about 50 Å of the dielectric material in contact with the threshold switching material.

22. The method of claim 16 , wherein forming a dielectric material comprises forming a dielectric material comprising aluminum oxide, aluminum silicon oxide, strontium oxide, barium oxide, strontium titanium oxide, magnesium oxide, a refractory metal oxide, a refractory metal alloy oxide, or combinations thereof.

23. The memory cell of claim 1 , wherein a thickness of the at least one doped dielectric material is between about 3 Å and about 5 Å.

24. The memory cell of claim 1 , wherein the threshold switching material is doped with at least one of boron, aluminum, gallium, or phosphorus.

25. The memory cell of claim 1 , wherein the at least one doped dielectric material is doped with oxygen, sulfur, carbon, fluorine, a metallic element, or combinations thereof.

26. The memory cell of claim 1 , wherein the at least one doped dielectric material is between the threshold switching material and one electrode of the pair of electrodes, the other electrode of the pair of electrodes in direct contact with the threshold switching material.

27. The memory cell of claim 1 , wherein the at least one doped dielectric material comprises aluminum silicon oxide, strontium oxide, barium oxide, strontium titanium oxide, or combinations thereof.

Assignees

• Micron Technology Inc

Inventors

• Chan Tsz W
• Ramaswamy D V Nirmal
• Tao Qian
• Hu Yongjun Jeff
• Mcteer Everett A

Classifications

• H01L45/04

  Electricity · mapped topic

• H01L45/1253

  Electricity · mapped topic

• H01L45/145 Primary

  Electricity · mapped topic

• H01L45/1608

  Electricity · mapped topic

• H01L27/2427

  Electricity · mapped topic