Electro-resistance element and electro-resistance memory using the same
An electro-resistance element that has a different configuration from conventional elements and is excellent in both affinity with semiconductor manufacturing processes and heat treatment stability under a hydrogen-containing atmosphere is provided. An electro-resistance element includes an electro-resistance layer that has two or more states in which electric resistance values are different and being switchable from one of the two or more states into another by applying a predetermined voltage or current. The electro-resistance layer includes first and second elements being capable of forming a nitride, and nitrogen.
1. An electro-resistance element comprising an electro-resistance layer,
the electro-resistance layer having two or more states in which electric resistance values are different and being switchable from one of the two or more states into another by applying a voltage or current in one phase, and
the electro-resistance layer comprising a nitride of a first element and a nitride of a second element,
wherein the electro-resistance layer switches between the two or more states in one phase based on a Colossal Electro-Resistance effect.
2. The electro-resistance element according to claim 1 , wherein the first and the second elements are a metallic element or Si.
3. The electro-resistance element according to claim 1 , wherein the first element is at least one selected from Ti, Ta, Co, Cu and Nb.
4. The electro-resistance element according to claim 1 , wherein the first element is Ti.
5. The electro-resistance element according to claim 1 , wherein the second element is at least one selected from Al, Hf, Cr and Si.
6. The electro-resistance element according to claim 1 , wherein the second element is Al.
7. The electro-resistance element according to claim 1 , wherein
the first element is Ti,
the second element is Al, and
a ratio Z of Al content X 2 (wt.%) in the electro-resistance layer to a sum of Ti content X 1 (wt.%) in the electro-resistance layer and the Al content X 2 (Z=X 2 /(X 1 +X 2 )) is 0.5 to 0.9.
8. The electro-resistance element according to claim 1 , wherein
a volume resistivity of the first element in a state of nitride is 10 −1 Ω·cm or lower, and
a volume resistivity of the second element in a state of nitride is 10 3 Ω·cm or greater.
9. The electro-resistance element according to claim 1 , wherein the electro-resistance layer further includes oxynitride.
10. The electro-resistance element according to claim 9 , wherein the electro-resistance layer includes an oxynitride of at least one element selected from the first and the second elements.
11. The electro-resistance element according to claim 10 , wherein the oxynitride is at grain boundaries in the electro-resistance layer.
12. The electro-resistance element according to claim 10 , wherein the electro-resistance layer has a granular structure in which domains are dispersed in a matrix, and at least a part of the domains is made of the oxynitride.
13. The electro-resistance element according to claim 9 , wherein the oxygen content in the electro-resistance layer is 10 wt.% or lower.
14. The electro-resistance element according to claim 1 , comprising a substrate and a multilayer structure disposed on the substrate,
the multilayer structure including an upper electrode and a lower electrode,
the electro-resistance layer being disposed between the upper and the lower electrodes.
15. The electro-resistance element according to claim 1 , wherein the voltage or current is in a pulse form.
16. An electro-resistance memory comprising the electro-resistance element according to claim 1 as a memory element.
17. The electro-resistance memory according to claim 16 , wherein two or more of the electro-resistance elements are aligned in a matrix.
18. The electro-resistance memory according to claim 17 , wherein the two or more of electro-resistance elements is connected to a switching element for selecting the element when recording and reading information.
19. The electro-resistance element according to claim 1 , wherein the resistivity of the nitride of the first element is lower than that of the nitride of the second element.
20. The electro-resistance element according to claim 1 , wherein the electro-resistance layer is made of a solid solution of the nitride of the first element and the nitride of the second element.
21. The electro-resistance element according to claim 1 , wherein the electro-resistance layer has a granular structure in which a domain of the nitride of the first element is dispersed in a matrix of the nitride of the second element.
22. The electro-resistance element according to claim 1 , wherein the electro-resistance layer has a structure in which a film of the nitride of the first element and a film of the nitride of the second element are layered alternately.
23. The electro-resistance element according to claim 1 , wherein the electro-resistance layer consists of the nitride of the first element and the nitride of the second element.
24. The electro-resistance element according to claim 23 , wherein the first element is at least one selected from Ti, Ta, Co, Cu and Nb.
25. The electro-resistance element according to claim 23 , wherein the second element is at least one selected from Al, Hf, Cr and Si.