1. A resistance random access memory device, comprising:
a first electrode;
a second electrode comprising material selected from the group consisting of silver, copper, zinc, gold, titanium, nickel, cobalt, tantalum, aluminum, and bismuth, alloys thereof, and silicides thereof; and
a variable resistance film provided between the first electrode and the second electrode, the variable resistance film comprising silicon oxynitride,
the variable resistance film comprising:
a first resistance change layer having a first nitrogen concentration; and
a second resistance change layer having a second nitrogen concentration lower than the first nitrogen concentration.
2. The resistance random access memory device according to claim 1, wherein a thickness of the variable resistance film is not more than 4 nm.
3. The resistance random access memory device according to claim 1, wherein a thickness of the first resistance change layer determined from a photoelectron spectrum is not more than 1 nm.
4. The resistance random access memory device according to claim 1, wherein the nitrogen concentration of the first resistance change layer is not less than 2 at% and not more than 15 at%.
5. The resistance random access memory device according to claim 4, wherein the nitrogen concentration of the first resistance change layer is determined from a photoelectron spectrum.
6. The resistance random access memory device according to claim 1, wherein the nitrogen concentration of the second resistance change layer is less than 2 at% and not less than 0 at%.
7. The resistance random access memory device according to claim 6, wherein the nitrogen concentration of the second resistance change layer is determined from a photoelectron spectrum.
8. The resistance random access memory device according to claim 1, further comprising a layer comprising silicon disposed between the first electrode and the variable resistance film or between the variable resistance film and the second electrode.
9. The resistance random access memory device according to claim 1, further comprising a layer comprising a metal oxide disposed between the first electrode and the variable resistance film or between the variable resistance film and the second electrode.
10. The resistance random access memory device according to claim 1, further comprising:
a first interconnect layer comprising a plurality of first interconnects extending in a first direction; and
a second interconnect layer comprising a plurality of second interconnects extending in a second direction crossing the first direction,
a stacked body comprising the first electrode, the variable resistance film, and the second electrode being disposed between each of the first interconnects and each of the second interconnects.
11. A resistance random access memory device, comprising:
a first electrode;
a second electrode comprising a metal; and
a variable resistance film provided between the first electrode and the second electrode, the variable resistance film comprising silicon, oxygen, and nitrogen, the variable resistance film having a nitrogen concentration gradient in a thickness direction thereof, the metal being able to reversibly move within the variable resistance film.
12. The resistance random access memory device according to claim 11, wherein a maximum value of the nitrogen concentration of the variable resistance film is not more than 15 at%.
13. The resistance random access memory device according to claim 11, wherein the nitrogen concentration of the variable resistance film is relatively high on the first electrode side and relatively low on the second electrode side.
14. The resistance random access memory device according to claim 11, wherein an oxygen concentration of the variable resistance film on the second electrode side is higher than that on the first electrode side.
15. The resistance random access memory device according to claim 11, wherein the variable resistance film comprises a silicon oxynitride film.
16. The resistance random access memory device according to claim 11, wherein the nitrogen concentration of the variable resistance film on the second electrode side is higher than that on the first electrode side.
17. The resistance random access memory device according to claim 11, further comprising a silicon layer disposed between the first electrode and the variable resistance film or between the variable resistance film and the second electrode.
18. The resistance random access memory device according to claim 11, further comprising a metal oxide layer disposed between the first electrode and the variable resistance film or between the variable resistance film and the second electrode.
19. The resistance random access memory device according to claim 11, further comprising:
a first interconnect layer including a plurality of first interconnects extending in a first direction; and
a second interconnect layer including a plurality of second interconnects extending in a second direction crossing the first direction,
a stacked body comprising the first electrode, the variable resistance film, and the second electrode being disposed between each of the first interconnects and each of the second interconnects.
20. The resistance random access memory device according to claim 11, wherein the metal is silver, copper, zinc, gold, titanium, nickel, cobalt, tantalum, aluminum, or bismuth.
The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.
1. A bistable display comprising:
a substrate; and
a layer of bistable material, and
wherein the layer of bistable material includes an embedded imagewise pattern that is viewable in a first state of the bistable material, hidden in a second state of the bistable material, and is not erasable,
wherein the layer of bistable material comprises areas of bistable material and areas of a filling material between the areas of bistable material, and
wherein the filling material comprises a second bistable material.
2. The display of claim 1, wherein the filling material comprises the bistable material and the second bistable material, wherein the second bistable material is different from the bistable material.
3. The display of claim 1, wherein the filling material is gelatin.
4. The display of claim 1, wherein the filling material has a different thickness than the bistable material.
5. The display of claim 1, wherein the bistable material comprises one or more of an electrochemical material, an electrophoretic material, an electrochromic material, a magnetic material, a ferroelectric material, a nematic liquid crystal material, or a chiral nematic liquid crystal material.
6. The display of claim 1, wherein the bistable material comprises one or more of a nematic liquid crystal material, or a chiral nematic liquid crystal material.
7. The display of claim 1, wherein the display further comprises a background layer on a side of the bistable material layer opposite the substrate.
8. The display of claim 1, wherein the bistable layer can be in a state selected from any bistable or gray scale state.
9. The display of claim 8, further comprising a background layer on a side of the bistable material layer opposite the substrate, wherein the background layer is the same in appearance as at least one of the states of the bistable layer.
10. The display of claim 1, further comprising a first conductor adjacent a first side of the bistable layer, and a second conductor adjacent a second side of the bistable layer.
11. A security device comprising a bistable display having
a substrate; and
a layer of bistable material, and
wherein the layer of bistable material includes an embedded imagewise pattern that is viewable in a first state of the bistable material, hidden in a second state of the bistable material, and is not erasable,
wherein the layer of bistable material comprises areas of bistable material and areas of a filling material between the areas of bistable material, and
wherein the filling material comprises a second bistable material.
12. The device of claim 11, wherein the bistable material is a liquid crystal.
13. The device of claim 11, wherein the device is a credit card, identification card, security badge, label, or document.
14. The display of claim 1, wherein the material of the layer of bistable material is altered according to the imagewise pattern.
15. The display of claim 1, wherein the embedded imagewise pattern is imprinted in material of the layer of bistable material.