Use of a symmetric resistive memory material as a diode to drive symmetric or asymmetric resistive memory
AssigneeInternational Business Machines Corporation
InventorKailash Gopalakrishnan
Life of this patent
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Abstract
A symmetrically resistive memory material (such as a phase change material) is described for use as a rectifying element for driving symmetric or asymmetric resistive memory elements in a crosspoint memory architecture. The crosspoint architecture has a plurality of electrodes and a plurality of crossbar elements, with each crossbar element being disposed between a first and a second electrode. The crossbar element is made of a symmetric resistive memory element used as a rectifier in series with a symmetric or asymmetric resistive memory element.
Claims6
1-21. (canceled)
A crosspoint array comprising:
- a plurality of bitlines and wordlines;
- and
- a plurality of crossbar elements, each crossbar element disposed between a bitline and a wordline and each crossbar element comprising at least a phase change material used as a rectifier in series with a solid electrolyte used as an asymmetric resistive memory element, said phase change material, in said ON state has a first resistance, RON, and in an OFF state has a second resistance, ROFF, with ROFF/RON≧104, where one or more of said crossbar elements are responsive to the following voltages:
- a first set of voltages to transition said phase change material in said crossbar elements from an OFF state to an ON state;
- a second set of voltages to read or program said solid electrolyte, and
- a third set of voltages to transition said phase change material from an ON state to an OFF state,
- wherein said solid electrolyte material includes at least one of the following:
- germanium sulfide (GexS1−x), germanium selenide (GexSe1−x), germanium telluride (GexTe1−x), silicon sulfide (SixS1−x), silicon selenide (SixSe1−x), silicon telluride (SixTe1−x), arsenic sulfide (AsxS1−x), arsenic selenide (AsxSe1−x), arsenic telluride (AsxTe1−x), lead sulfide (PbxS1−x), lead selenide (PbxSe1−x), lead telluride (PbxTe1−x), cadmium sulfide (CdxS1−x), cadmium selenide (CdxSe1−x), cadmium telluride (CdxTe1−x), zinc sulfide (ZnxS1−x), zinc selenide (ZnxSe1−x), zinc telluride (ZnxTe1−x), silver sulfide (AgxS), silver selenide (AgxSe), copper sulfide (CuxS), copper selenide (CuxSe), tungsten oxide (WOx), copper oxide (CuxO), silver (Ag), copper (Cu), lithium (Li), sodium (Na), and zinc (Zn).
23-24. (canceled)
26-29. (canceled)
A method for use with a crosspoint array, said crosspoint array comprising a plurality of bitlines and wordlines and a plurality of crossbar elements, each crossbar element disposed between a bitline and a wordline, each crossbar element comprising at least a phase change material used as a rectifier in series with a solid electrolyte, said method comprising the steps of:
- applying a first set of voltages to at least one of said crossbar elements, said first set of voltages transitioning said phase change material in said crossbar elements from an OFF state to an ON state;
- applying a second set of voltages to at least one of said crossbar elements, said second set of voltages reading or programming said solid electrolyte,
- applying a third set of voltages to at least one of said crossbar elements, said third set of voltages transitioning said phase change material from an ON state to an OFF state,
- said phase change material, in said ON state has a first resistance, RON, and in an OFF state has a second resistance, ROFF, with ROFF/RON≧104, and
- said solid electrolyte material includes at least one of the following:
- germanium sulfide (GexS1−x), germanium selenide (GexSe1−x), germanium telluride (GexTe1−x), silicon sulfide (SixS1−x), silicon selenide (SixSe1−x), silicon telluride (SixTe1−x), arsenic sulfide (AsxS1−x), arsenic selenide (AsxSe1−x), arsenic telluride (AsxTe1−x), lead sulfide (PbxS1−x), lead selenide (PbxSe1−x), lead telluride (PbxTe1−x), cadmium sulfide (CdxS1−x), cadmium selenide (CdxSe1−x), cadmium telluride (CdxTe1−x), zinc sulfide (ZnxS1−x), zinc selenide (ZnxSe1−x), zinc telluride (ZnxTe1−x), silver sulfide (AgxS), silver selenide (AgxSe), copper sulfide (CuxS), copper selenide (CuxSe), tungsten oxide (WOx), copper oxide (CuxO), silver (Ag), copper (Cu), lithium (Li), sodium (Na), and zinc (Zn).
Dependencies are inferred from the claim text.