Programming enhancement in self-selecting memory
Methods, systems, and devices for programming enhancement in memory cells are described. An asymmetrically shaped memory cell may enhance ion crowding at or near a particular electrode, which may be leveraged for accurately reading a stored value of the memory cell. Programming the memory cell may cause elements within the cell to separate, resulting in ion migration towards a particular electrode. The migration may depend on the polarity of the cell and may create a high resistivity region and low resistivity region within the cell. The memory cell may be sensed by applying a voltage across the cell. The resulting current may then encounter the high resistivity region and low resistivity region, and the orientation of the regions may be representative of a first or a second logic state of the cell.
1. A method of forming a memory device, comprising:
forming a material stack comprising a first conductive material, a second conductive material, and a chalcogenide material between the first conductive material and the second conductive material;
a first removing of material from the material stack to form a plurality of memory cell stacks each comprising a chalcogenide material memory component that comprises:
a first face bounded by a first side, a second side, a third side, and a fourth side, wherein the first side and the third side form a first obtuse angle and the second side and the third side form a first acute angle, and
a second face adjacent to the first face and bounded by a fifth side, a sixth side, a seventh side, and an eighth side;
a second removing of material from the plurality of memory cell stacks, wherein, after the second removing, the fifth side and the seventh side form a second obtuse angle and the sixth side and the seventh side form a second acute angle; and
depositing a dielectric material about the plurality of memory cell stacks.
2. The method of claim 1 , wherein the plurality of memory cell stacks each comprise a first conductor comprising the first side of the chalcogenide material memory component and a second conductor comprising the second side of the chalcogenide material memory component, and wherein after the first removing, a first dimension of the first side is different than a second dimension of the second side.
3. The method of claim 2 , wherein the first dimension of the first side is less than to the second dimension of the second side.
4. The method of claim 1 , comprising:
forming a first access line coupled to the first conductive material; and
forming a second access line coupled to the second conductive material.
5. The method of claim 4 , wherein the first conductive material is different from the second conductive material.
6. The method of claim 5 , wherein the chalcogenide material comprises at least one of selenium, arsenic, germanium, silicon, or tellurium.
7. The method of claim 1 , wherein the first removing of material comprises etching beginning at the first conductive material.
8. The method of claim 1 , wherein the first removing of material comprises etching beginning at the second conductive material.
9. The method of claim 1 , wherein the dielectric material comprises at least one of silicon nitride, silicon oxide, aluminum oxide, or hafnium oxide.
10. The method of claim 1 , wherein the plurality of memory cell stacks each comprise a first conductor comprising the fifth side of the chalcogenide material memory component and a second conductor comprising the sixth side of the chalcogenide material memory component, and wherein after the second removing, a third dimension of the fifth side is different than a fourth dimension of the sixth side.
11. The method of claim 10 , wherein the third dimension of the fifth side is less than the fourth dimension of the sixth side.
12. The method of claim 1 , wherein the chalcogenide material comprises selenium, and wherein a concentration of the selenium relative to the first conductive material or the second conductive material is based at least in part on a polarity of a voltage across the chalcogenide material.
13. The method of claim 1 , wherein a first dimension of the first side is less than half of a second dimension of the second side.
14. The method of claim 1 , wherein the chalcogenide material comprises a self-selecting memory component.
15. The method of claim 1 , wherein:
the first side of the first face is located above the second side of the first face,
the fifth side of the second face is located above the sixth side of the second face; and
the third side of the first face is the seventh side of the second face.
16. The method of claim 1 , wherein, after the first removing, the fifth side and the seventh side form a substantially 90 degree angle and the sixth side and the seventh side form a substantially 90degree angle.
17. The method of claim 1 , wherein the plurality of memory cell stacks each comprise:
a first conductor comprising a ninth side, the first side of the chalcogenide material memory component, a tenth side, and an eleventh side, wherein the ninth side and the tenth side from a substantially 90 degree angle and the ninth side and the eleventh side from a substantially 90 degree angle, and
a second conductor comprising a twelfth side, the second side of the chalcogenide material memory component, a thirteenth side, and a fourteenth side, wherein the twelfth side and the thirteenth side form a substantially 90 degree angle and the twelfth side and the fourteenth side form a substantially 90 degree angle.
18. The method of claim 1 , wherein, after the first removing and the second removing, the chalcogenide material memory component is a frustum.