Magnetoresistive element
View Patent ↗A magnetoresistive element includes a first ferromagnetic layer having a first magnetization, the first magnetization having a first pattern when the magnetoresistive element is half-selected during a first data write, a second pattern when the magnetoresistive element is selected during a second data write, and a third pattern of residual magnetization, the first pattern being different from the second and third pattern, a second ferromagnetic layer having a second magnetization, and a nonmagnetic layer arranged between the first ferromagnetic layer and the second ferromagnetic layer and having a tunnel conductance changing dependent on a relative angle between the first magnetization and the second magnetization.
1. A magnetoresistive element comprising:
a first ferromagnetic layer having a first magnetization, the first magnetization having a first pattern when the magnetoresistive element is half-selected during a first data write, a second pattern when the magnetoresistive element is selected during a second data write, and a third pattern of residual magnetization, the first pattern being different from the second and third pattern;
a second ferromagnetic layer having a second magnetization; and
a nonmagnetic layer arranged between the first ferromagnetic layer and the second ferromagnetic layer and having a tunnel conductance changing dependent on a relative angle between the first magnetization and the second magnetization.
2. The element according to claim 1 , wherein the first pattern forms a C-shaped domain and the third pattern forms an S-shaped domain.
3. The element according to claim 1 , wherein the first pattern forms at least one C-shaped domain.
4. A magnetic random access memory comprising:
a first write line through which a first write current flows;
a second write line through which a second write current flows and crossing the first write line;
a third write line crossing the first write line;
a first memory cell comprising a first magnetoresistive element arranged at a intersection region between the first write line and the second write line, the first magnetoresistive element being applied with magnetic fields generated by the first write current and the second write current; and
a second memory cell comprising a second magnetoresistive element arranged at a intersection region between the first write line and the third write line, the second magnetoresistive element being applied with a magnetic field generated by the first write current, and a magnetization pattern of the second magnetoresistive element during a first data write being different from a magnetization pattern of the first magnetoresistive element during a second data write.
5. The memory according to claim 4 , wherein the magnetization pattern of the second magnetoresistive element when the first write current and the second write current flow forms a C-shaped domain.
6. The memory according to claim 4 , wherein a pattern of residual magnetization of the first magnetoresistive element and the second magnetoresistive element forms an S-shaped domain.
7. The memory according to claim 4 , wherein each of the first magnetoresistive element and the second magnetoresistive element has a structure comprising two ferromagnetic layers and a tunnel barrier layer sandwiched between the two ferromagnetic layers, and a tunnel conductance of the tunnel barrier layer changes depending on a relative angle between magnetizations of the two ferromagnetic layers.
8. The memory according to claim 4 , wherein each of the first magnetoresistive element and the second magnetoresistive element has a first portion running in a first direction and a second portion projecting in a second direction perpendicular to the first direction from a side surface of the first portion.
9. The memory according to claim 4 , wherein the magnetization pattern of the second magnetoresistive element when the first write current and the second write current flow forms two C-shaped domains.
10. The memory according to claim 8 , wherein each of the first magnetoresistive element and the second magnetoresistive element has two times-rotation symmetry and is asymmetrical about a central axis extending in the first direction and a central axis extending in the second direction.
11. The memory according to claim 8 , wherein the first portion has a parallelogram shape longer in the first direction than in the second direction, and the second portion projects in the second direction from a side of the parallelogram shape.
12. The memory according to claim 8 , wherein the first portion has a rectangular shape longer in the first direction than in the second direction, the second portion projects in the second direction from a side of the rectangle shape, and corners present on at least one of two diagonal lines of the rectangle shape are cut off.
13. The memory according to claim 8 , wherein convex portions projecting in the second direction are provided at two ends of the first portion in the first direction.
14. The memory according to claim 8 , wherein a maximum width of the first magnetoresistive element and the second magnetoresistive element in the second direction is not more than 1 μm.
15. The memory according to claim 8 , wherein all corners of the first portion and the second portion are round.
16. The memory according to claim 8 , wherein a thickness of the first magnetoresistive element and the second magnetoresistive element is 3 to 50 nm.
17. The memory according to claim 12 , wherein the corners present on one of the two diagonal lines are cut off in a larger amount than corners present on the other diagonal line.
18. The memory according to claim 14 , wherein a length of the first magnetoresistive element and the second magnetoresistive element in the first direction has a value in a range of one to ten times a maximum width in the second direction.