Phase change current density control structure
View Patent ↗A phase change memory element and method of forming the same. The memory element includes first and second electrodes. A first layer of phase change material is between the first and second electrodes. A second layer including a metal-chalcogenide material is also between the first and second electrodes and is one of a phase change material and a conductive material. An insulating layer is between the first and second layers. There is at least one opening in the insulating layer providing contact between the first and second layers.
1. A single memory element comprising:
a first electrode;
a second electrode spaced from the first electrode;
a first region of phase change material between the first and second electrodes;
a second region comprising one of a phase change material and a conductive material between the first region of phase change material and the second electrode;
an insulating material separating at least a portion of the first region from at least a portion of the second region; and
at least two openings in the insulating material allowing contact between the first and second regions to define the single memory element, wherein at least a portion of each of the at least two openings is located in a region directly between the first and second electrodes.
2. The memory element of claim 1 , wherein the first region comprises a chalcogenide material.
3. The memory element of claim 2 , wherein the first region comprises germanium-telluride.
4. The memory element of claim 1 , wherein the first region has a thickness of about 300 Å to about 500 Å.
5. The memory element of claim 4 , wherein the second region comprises tin-telluride.
6. The memory element of claim 1 , wherein the second region has a thickness of about 500 Å to about 700 Å.
7. The memory element of claim 1 , wherein the insulating material comprises amorphous carbon.
8. The memory element of claim 1 , wherein at least one of the first and second electrodes comprise tungsten.
9. The memory element of claim 1 , wherein the at least two openings are at least partially directly above the second electrode.
10. The memory element of claim 1 , wherein the at least two openings are configured to increase current density during operation of the element.
11. The memory element of claim 1 , wherein the at least two openings have a surface area less than a surface area of one of the first and second electrodes.
12. A memory array comprising:
a first electrode;
a second electrode spaced from the first electrode;
a phase change material between the first and second electrodes;
a metal-chalcogenide material between the phase change material and the second electrode;
an insulating material between the phase change material and the metal chalcogenide material
separating at least a portion of the phase change material from a portion of the metal chalcogenide material; and
at least two openings in the insulating material allowing contact between the phase change material and the metal-chalcogenide material, wherein in at least a portion of each of the at least two openings is located directly above the second electrode.
13. The memory array of claim 12 , wherein the phase change material comprises germanium-telluride.
14. The memory array of claim 12 , wherein the first phase change material has a thickness of about 300 Å to about 500 Å.
15. The memory array of claim 12 , wherein the metal-chalcogenide material comprises tin-telluride.
16. The memory array of claim 12 , wherein the metal-chalcogenide material has a thickness of about 500 Å to about 700 Å.
17. The memory array of claim 12 , wherein the insulating material comprises amorphous carbon.
18. The memory array of claim 12 , wherein at least one of the first and second electrodes comprise tungsten.
19. The memory array of claim 12 , wherein the at least two openings have a surface area less than a surface area of the second electrode.