Nonvolatile memory device using a tunnel nitride as a current limiter element
View Patent ↗Embodiments of the invention generally include a method of forming a nonvolatile memory device that contains a resistive switching memory element that has an improved device switching performance and lifetime, due to the addition of a current limiting component disposed therein. In one embodiment, the current limiting component comprises a resistive material that is configured to improve the switching performance and lifetime of the resistive switching memory element. The electrical properties of the current limiting layer are configured to lower the current flow through the variable resistance layer during the logic state programming steps (i.e., “set” and “reset” steps) by adding a fixed series resistance in the resistive switching memory element found in the nonvolatile memory device. In one embodiment, the current limiting component comprises a tunnel nitride that is a current limiting material that is disposed within a resistive switching memory element in a nonvolatile resistive switching memory device.
1. A nonvolatile memory element, comprising:
a first layer operable as an electrode;
a second layer operable as an electrode;
a third layer operable as a variable resistance layer and disposed between the first electrode layer and the second electrode layer, wherein the third layer comprises a metal oxide;
a fourth layer operable as a current limiting layer disposed between the first layer and the third layer, wherein the fourth layer comprises a tunnel nitride; and
a fifth layer comprising an oxygen deficient material disposed between the third layer and the fourth layer.
2. The nonvolatile memory element of claim 1 , wherein the third layer comprises a material selected from the group consisting of hafnium oxide, zirconium oxide, lanthanum oxide, and aluminum oxide.
3. The nonvolatile memory element of claim 1 , wherein the third layer has a thickness of between 20 angstroms and 100 angstroms.
4. The nonvolatile memory element of claim 1 , wherein the fourth layer comprises a material selected from the group consisting of aluminum nitride, zirconium nitride, gallium nitride, boron nitride, titanium silicon nitride and silicon nitride.
5. The nonvolatile memory element of claim 1 , wherein the fourth layer has a thickness of between 10 angstroms and 30 angstroms.
6. The nonvolatile memory element of claim 1 , wherein the fifth layer comprises a material selected from the group consisting of tantalum nitride, titanium nitride, tungsten nitride, silicon oxy-nitride, aluminum oxy-nitride, aluminum nitride, hafnium nitride zirconium nitride, boron nitride, calcium nitride, ruthenium titanium nitride, gold, zirconium platinum and platinum beryllium.
7. The nonvolatile memory element of claim 1 ,
wherein the fifth layer comprises a first sub-layer and a second sub-layer;
wherein the first sub-layer comprises a material selected from the group consisting of tantalum nitride, titanium nitride, tungsten nitride, silicon oxy-nitride, aluminum oxy-nitride, aluminum nitride, hafnium nitride zirconium nitride, boron nitride, calcium nitride, ruthenium titanium nitride, gold, zirconium platinum and platinum beryllium; and
wherein the second sub-layer comprises a material selected from the group consisting of ruthenium, ruthenium oxide, iridium, iridium oxide, titanium, titanium nitride, tantalum, tantalum nitride, platinum, platinum beryllium, gold, and silver.
8. A nonvolatile memory element, comprising:
a first layer operable as an electrode;
a second layer operable as an electrode;
a third layer operable as a variable resistance layer disposed between the first layer and the second layer, the third layer comprising a metal oxide;
a fourth layer operable as a current limiting layer disposed between the first layer and the third layer, the fourth layer comprising a tunnel nitride;
a fifth layer disposed between the fourth layer and the third layer, the fifth layer operable to inhibit diffusion of oxygen ions between the third layer and the fourth layer; and
a sixth layer and a seventh layer, wherein the fourth layer is disposed between the sixth layer and seventh layer, the sixth layer and the seventh layer operable to provide nitrogen ions to the fourth layer.
9. The nonvolatile memory element of claim 8 , wherein the third layer comprises a material selected from the group consisting of hafnium oxide, zirconium oxide, lanthanum oxide and aluminum oxide.
10. The nonvolatile memory element of claim 8 , wherein the third layer has a thickness of between 20 angstroms and 100 angstroms.
11. The nonvolatile memory element of claim 8 , wherein the fourth layer comprises a material selected from the group consisting of aluminum nitride, zirconium nitride, gallium nitride, boron nitride, titanium silicon nitride and silicon nitride.
12. The nonvolatile memory element of claim 8 , wherein the fourth layer has a thickness of between 10 angstroms and 30 angstroms.
13. The nonvolatile memory element of claim 8 , wherein the fifth layer comprises a material selected from the group consisting of tantalum nitride, titanium nitride, tungsten nitride, silicon oxy nitride, aluminum oxy-nitride, aluminum nitride, hafnium nitride, zirconium nitride, gold, zirconium, platinum and platinum beryllium.
14. The nonvolatile memory element of claim 8 , wherein the fifth layer has a thickness of between 30 angstroms and 100 angstroms.
15. The nonvolatile memory element of claim 8 , wherein the sixth layer and the seventh layer each comprise a material selected from the group consisting of titanium nitride tantalum nitride, tantalum-aluminum nitride, zirconium nitride, hafnium nitride, yttria nitride, scandium nitride, lanthanum nitride, aluminum nitride, magnesium nitride, calcium nitride, strontium nitride, barium nitride, other rare-earth nitrides, or combinations thereof.
16. The nonvolatile memory element of claim 8 , wherein the sixth layer has a thickness of between 50 angstroms and 100 angstroms.
17. The nonvolatile memory element of claim 15 , wherein the sixth layer and the seventh layer each comprise a material selected from the group of titanium nitride tantalum nitride, tantalum-aluminum nitride, zirconium nitride, hafnium nitride, yttria nitride, scandium nitride, lanthanum nitride, aluminum nitride, magnesium nitride, calcium nitride, strontium nitride, barium nitride, that are not the same.
18. A method of forming a nonvolatile memory element, comprising:
forming a first layer operable as a first electrode;
forming a second layer operable as second electrode;
forming a third layer operable as a variable resistance layer comprising a metal oxide, wherein the third layer is disposed between the first layer and the second layer;
forming a fourth layer operable as current limiting layer, wherein the fourth layer is disposed between the first layer and the third layer;
forming a fifth layer comprising an oxygen deficient material, wherein the fifth layer is disposed between the fourth layer and the third layer;
forming a sixth layer comprising a nitrogen rich material operable to provide nitrogen ions to the fourth layer;
forming a seventh layer comprising a nitrogen rich material operable to provide nitrogen ions to the fourth layer;
wherein the fourth layer is disposed between the sixth layer and the seventh layer; and
wherein the fifth layer comprises a material selected from the group of tantalum nitride, titanium nitride and tungsten nitride, silicon oxy-nitride, aluminum oxy-nitride, aluminum nitride, hafnium nitride zirconium nitride, gold, zirconium platinum and platinum beryllium.
19. The method of claim 18 , wherein the fourth layer comprises a material selected from the group consisting of aluminum nitride, zirconium nitride, gallium nitride, boron nitride, titanium silicon nitride and silicon nitride.