Information storage devices using magnetic domain wall movement and methods of operating the same

• US 8,320,152 B2
• Filed: 04/22/2009
• Issued: 11/27/2012
• Est. Priority Date: 07/14/2008
• Status: Active Grant

• Current Assignee: Samsung Electronics Co. Ltd.
• Original Assignee: Samsung Electronics Co. Ltd.
• Inventors: Cho, Young-jin, Shin, Hyung-soon, Lee, Seung-jun, Seo, Sun-ae, Lee, Sung-chul, Bae, Ji-young
• Primary Examiner(s): Sofocleous, Alexander
• Assistant Examiner(s): NGUYEN, HIEN N
• Application Number:
  US12/385,859
• Publication Number:
  US 20100008135A1
• Time in Patent Office: 1,315 Days
• Field of Search: 365/80, 365/81, 365/171, 365/173, 365 83- 90, 977/933, 977/935
• US Class Current: 365/80
• CPC Class Codes: G01R 33/12 Measuring magnetic properties of articles or specimens of solids or fluids involving magnetic resonance G01R33/20
• CPC Class Codes: G01R 33/1207 Testing individual magnetic storage devices, e.g. records carriers or digital storage elements functional testing G06F11/00, G06F11/28
• CPC Class Codes: G01R 33/1284 Spin resolved measurements; Influencing spins during measurements, e.g. in spintronics devices G01R33/093 takes precedence; semiconductor devices using spin polarized carriers H01L29/66984
• CPC Class Codes: G01R 33/1292 Measuring domain wall position or domain wall motion
• CPC Class Codes: G11C 11/161 details concerning the memory cell structure, e.g. the layers of the ferromagnetic memory cell
• CPC Class Codes: G11C 11/1659 Cell access
• CPC Class Codes: G11C 11/1675 Writing or programming circuits or methods
• CPC Class Codes: G11C 19/0808 using magnetic domain propagation
• CPC Class Codes: G11C 19/0841 using electric current

Abstract

An information storage device includes a storage node, a write unit configured to write information to a first magnetic domain region of the storage node, and a read unit configured to read information from a second magnetic domain region of the storage node. The information storage device further includes a temporary storage unit configured to temporarily store information read by the read unit, and a write control unit electrically connected to the temporary storage unit and configured to control current supplied to the write unit. The information read from the second magnetic domain region is stored in the temporary storage unit and written to the first magnetic domain region.

Claims

1. An information storage device comprising:

a storage node including a plurality of magnetic domain regions, and magnetic domain walls arranged between the magnetic domain regions;

a write unit configured to write information to a first magnetic domain region of the storage node;

a read unit configured to read information from a second magnetic domain region of the storage node;

a magnetic domain wall moving unit electrically connected to the storage node, the magnetic domain wall moving unit being configured to move the magnetic domain walls;

a temporary storage unit electrically connected to the read unit, the temporary storage unit being configured to temporarily store information read by the read unit; and

a write control unit electrically connected to the temporary storage unit and the write unit, the write control unit being configured to control current supplied to the write unit.

2. The information storage device of claim 1, wherein the first magnetic domain region is adjacent to a first end of the storage node, and the second magnetic domain region corresponds to a second end of the storage node.

3. The information storage device of claim 2, wherein the first end of the storage node is magnetized in a given direction.

4. The information storage device of claim 1, further comprising:

a plurality of word lines; and

a plurality of bit lines intersecting the plurality of word lines;

wherein

a first end of the storage node is connected to a first of the plurality of word lines,

a second end of the storage node is connected to one of a first and a second ones of the plurality of bit lines,

a first electrode of the write unit is connected to a second of the plurality of word lines, the first electrode being disposed on a bottom of the first magnetic domain region,

a second electrode of the write unit is connected to the second of the plurality of bit lines, the second electrode being disposed on a top of the first magnetic domain region,

a first electrode of the read unit is connected to the first of the plurality of bit lines,

a second electrode of the read unit is connected to a third of the plurality of word lines,

the temporary storage unit is connected to the first of the plurality of bit lines, and the write control unit is connected to the second of the plurality of bit lines.

5. The information storage device of claim 4, further comprising:

a first switching unit arranged between the first end of the storage node and the first of the plurality of word lines;

a second switching unit arranged between the first electrode of the write unit and the second of the plurality of word lines; and

a third switching unit arranged between the second electrode of the read unit and the third of the plurality of word lines.

6. The information storage device of claim 4, further comprising:

a fourth switching unit arranged between the first or second of the plurality of bit lines, which is connected to the second end of the storage node, and the second end of the storage node; and

wherein

a fourth of the plurality of word lines is connected to the fourth switching unit.

7. The information storage device of claim 6, wherein the first and the fourth of the plurality of word lines are connected to a common voltage source.

8. The information storage device of claim 6, wherein the storage node, the plurality of word lines, the plurality of bit lines, and the first through fourth switching units form a unit memory region, a plurality of the unit memory regions being arranged to form a memory array.

9. The information storage device of claim 4, wherein the second of the plurality of word lines and the third of the plurality of word lines are connected to a common voltage source.

10. The information storage device of claim 9, further comprising:

a peripheral circuit region configured to drive and control the memory array, wherein

the magnetic domain wall moving unit, the temporary storage unit, and the write control unit are included in the peripheral circuit region; and

a decoder arranged between the memory array and the peripheral circuit region.

11. The information storage device of claim 4, wherein the second end of the storage node is connected to the first of the plurality of bit lines, and the magnetic domain wall moving unit is connected to the first of the plurality of bit lines.

12. The information storage device of claim 1, wherein the magnetic domain wall moving unit includes,

a current source configured to supply current to the storage node;

and

a switching unit connected between the storage node and the current source.

13. The information storage device of claim 1, further comprising:

a sense unit connected between the temporary storage unit and the read unit.

14. The information storage device of claim 13, wherein the temporary storage unit includes,

a latch connected to an output terminal of the sense unit.

15. The information storage device of claim 1, wherein the write control unit includes,

a current source configured to supply current to the write unit,

a switching unit connected between the current source and the write unit, and

a logic device connected between the switching unit and the temporary storage unit.

16. A method of operating the information storage device of claim 1 comprising:

a first operation of reading information from the second magnetic domain region and storing the read information in the temporary storage unit; and

a second operation of moving the magnetic domain walls of the storage node toward the second magnetic domain region.

17. The method of claim 16, further comprising:

a third operation of selectively writing information to the first magnetic domain region.

18. The method of claim 17, wherein the information written to the first magnetic domain region in the third operation is the same as the information read in the first operation.

19. The method of claim 17, wherein the first magnetic domain region is adjacent to a first end of the storage node, the second magnetic domain region corresponds to a second end of the storage node, and the first end of the storage node is a third magnetic domain region magnetized in a first direction.

20. The method of claim 19, wherein, in the second operation, the third magnetic domain region extends to the first magnetic domain region, and if the information read in the first operation corresponds to information stored in the third magnetic domain region, a write current is not supplied to the first magnetic domain region in the third operation.

21. The method of claim 19, wherein the third magnetic domain region extends to the first magnetic domain region in the second operation, and if the information read in the first operation does not correspond to information stored in the third magnetic domain region, a write current is supplied to the first magnetic domain region in the third operation.

22. The method of claim 16, wherein after the second operation, the method further comprises:

a third operation of selectively writing the information read in the first operation to the first magnetic domain region concurrently with reading of the information from the second magnetic domain region.

23. The method of claim 22, wherein the first magnetic domain region is adjacent to a first end of the storage node, the second magnetic domain region corresponds to a second end of the storage node, and the first end of the storage node is a magnetic domain magnetized in a first direction.

24. The method of claim 23, wherein, if the information read in the first operation corresponds to information stored in the first end of the storage node, a write current is not supplied to the first magnetic domain region in the third operation, and if the information read in the first operation does not correspond to information stored in the first end of the storage node, the write current is supplied to the first magnetic domain region in the third operation.

25. An information storage device comprising:

a storage node including a plurality of magnetic domains, a magnetic domain wall being arranged between each pair of adjacent magnetic domains;

a write unit arranged at a first magnetic domain region of the storage node adjacent to a first end of the storage node, wherein the first end of the storage node is magnetized in a first magnetization direction; and

a read unit arranged at a second magnetic domain region of the storage node, wherein the second magnetic domain region is at a second end of the storage node.

26. The information storage device of claim 25, wherein the first magnetization direction represents a first information type, and the write unit is configured to write information to the first magnetic domain region by selectively applying a write current to the first magnetic domain region, the information corresponding to the first or a second magnetization direction.

27. The information storage device of claim 26, wherein the write unit applies the write current to the first magnetic domain region only if the information corresponds to the second magnetization direction.

28. The information storage device of claim 25, wherein the write unit and the read unit are connected to different bit lines.

29. The information storage device of claim 25, wherein the write unit and the read unit are connected to a common bit line.

30. The information storage device of claim 25, further comprising:

a plurality of word lines; and

a plurality of bit lines intersecting the plurality of word lines;

wherein

a first end of the storage node is connected to a first of the plurality of word lines,

a second end of the storage node is connected to one of a first and a second ones of the plurality of bit lines,

a first electrode of the write unit is connected to a second of the plurality of word lines,

a second electrode of the write unit is connected to the second of the plurality of bit lines,

a first electrode of the read unit is connected to one of the first and second of the plurality of bit lines,

a second electrode of the read unit is connected to a third of the plurality of word lines.

31. The information storage device of claim 30, further comprising:

a first switching unit arranged between the first end of the storage node and the first of the plurality of word lines;

a second switching unit arranged between the first electrode of the write unit and the second of the plurality of word lines; and

a third switching unit arranged between the second electrode of the read unit and the third of the plurality of word lines.

32. The information storage device of claim 31, further comprising:

a fourth switching unit arranged between the first or second of the plurality of bit lines, which is connected to the second end of the storage node, and the second end of the storage node;

wherein

a fourth of the plurality of word lines is connected to the fourth switching unit.

33. The information storage device of claim 25, further comprising:

a magnetic domain wall moving unit electrically connected to the storage node, the magnetic domain wall moving unit being configured to move the magnetic domain walls;

a temporary storage unit electrically connected to the read unit, the temporary storage unit being configured to temporarily store information read by the read unit; and

a write control unit electrically connected to the temporary storage unit and the write unit, the write control unit being configured to control current supplied to the write unit.

34. The information storage device of claim 33, further comprising:

a sense unit connected between the temporary storage unit and the read unit.

35. The information storage device of claim 34, wherein the temporary storage unit includes a latch connected to an output terminal of the sense unit.

36. The information storage device of claim 33, wherein the write control unit includes,

a current source configured to supply current to the write unit,

a switching unit connected between the current source and the write unit, and

a logic device connected between the switching unit and the temporary storage unit.

37. The information storage device of claim 25, wherein the write unit is arranged on the first magnetic domain region, and the first magnetic domain region is adjacent to an end magnetic domain region at the first end of the storage node.

38. A method of operating the information storage device of claim 25, wherein the first end of the storage node is an end magnetic domain region magnetized in the first magnetization direction, the method comprising:

recording first information by magnetizing the first magnetic domain region in a direction opposite to the first magnetization direction; and

moving the first information toward the second end of the storage node to an adjacent second magnetic domain region of the storage node while extending the end magnetic domain region to the first magnetic domain region by supplying current to the storage node.