Phase change memory cell with constriction structure

Patent metadata

Field	Value
Publication number	US-10008664-B2
Application number	US-201615063238-A
Country	US
Kind code	B2
Filing date	Mar 7, 2016
Priority date	Mar 14, 2008
Publication date	Jun 26, 2018
Grant date	Jun 26, 2018

Abstract

Some embodiments include methods of forming memory cells. Such methods can include forming a first electrode, a second electrode, and a memory element directly contacting the first and second electrodes. Forming the memory element can include forming a programmable portion of the memory element isolated from the first electrode by a first portion of the memory element and isolated from the second electrode by a second portion of the memory element. Other embodiments are described.

First claim

What is claimed is:

1. A device comprising:
a first electrode and a second electrode;
a memory element directly contacting the first and second electrodes, the memory element including a programmable portion having a material configured to change between multiple phases to store information based on a resistance state of an amorphous region of the programmable portion, wherein the programmable portion is isolated from the first electrode by a first portion of the memory element, and wherein the programmable portion is isolated from the second electrode by a second portion of the memory element, and the resistance state is based on a size of the amorphous region; and wherein
the first portion of the memory element includes a tapered part and a larger part, the larger part is between the tapered part and the first electrode, and the programmable portion includes at least a part of the tapered part;
the second portion of the memory element includes a first part and a second part, the first part contacts the second electrode, the second part is between the first part and the tapered part, wherein the first part and the second part have a same width, and the width is measured in a direction perpendicular to a direction from the first electrode to the second electrode; and
the programmable portion having the material configured to change between multiple phases includes a portion of the tapper part and a portion of the second part.

2. The device of claim 1 , wherein the memory element is configured to cause the material of the programmable portion to have a first phase of the multiple phases and to cause a material of each of the first and second portions to have a second phase of the multiple phases.

3. The device of claim 2 , wherein the material of programmable portion and the material at each of the first and second portion include chalcogenide material.

4. The device of claim 1 , wherein a material of each of the first and second portion has a crystalline phase.

5. The device of claim 1 , wherein the programmable portion is configured to store information representing multiple bits.

6. The device of claim 1 , wherein the memory element is configured to cause the size of the amorphous region to have a first thickness corresponding to a first value of the resistance state, and a second thickness corresponding to a second value of the resistance state.

7. The device of claim 6 , wherein the memory element is configured to cause the size of the amorphous region to have a third thickness corresponding to a third value of the resistance state.

8. The device of claim 1 , wherein the memory element is configured to cause the size of the amorphous region to have a first thickness corresponding to a first value of information stored in the memory element, and a second thickness corresponding to a second value of information stored in the memory element.

9. The device of claim 8 , wherein the memory element is configured to cause the size of the amorphous region to have a third thickness corresponding to a third first value of information stored in the memory element.

10. The device of claim 1 , wherein the first portion includes a first cross-section area to pass a first current, the second portion includes a second cross-section area to pass a second current, and the programmable portion includes a third cross-section to pass a third current, and the third cross-section area is smaller than each of the first and second cross-section areas.

11. The device of claim 1 , wherein the programmable portion includes chalcogenide material.

12. The device of claim 1 , wherein the material includes a compound of germanium, antimony, and tellurium.

13. The device of claim 1 , further comprising an access component coupled to the memory element.

14. The device of claim 13 , wherein one of the access component and the memory element is coupled to a wordline, and the other one of the access component and the memory element is coupled to a bit line.

15. The device of claim 13 , wherein the access component includes a field-effect transistor coupled to a wordline, and the memory element is coupled to a bit line.

16. The device of claim 13 , wherein the access component includes a bipolar junction transistor coupled to a wordline, and the memory element is coupled to a bit line.

17. The device of claim 13 , wherein the access component includes a diode coupled to a wordline, and the memory element is coupled to a bit line.

Assignees

• Micron Technology Inc

Inventors

• Liu Jun
• Violette Michael P

Classifications

• H01L45/1233

  Electricity · mapped topic

• H01L45/144

  Electricity · mapped topic

• H01L45/1246

  Electricity · mapped topic

• H01L45/1683

  Electricity · mapped topic

• H01L45/06 Primary

  Electricity · mapped topic