METHOD AND SYSTEM FOR PROVIDING SPIN TRANSFER TUNNELING MAGNETIC MEMORIES UTILIZING UNIDIRECTIONAL POLARITY SELECTION DEVICES

• US 20090185410A1
• Filed: 01/22/2008
• Published: 07/23/2009
• Est. Priority Date: 01/22/2008
• Status: Abandoned Application

• Current Assignee: Grandis, Inc. (Samsung Electronics Co. Ltd.)
• Original Assignee: Grandis, Inc. (Samsung Electronics Co. Ltd.)
• Inventors: Albert, Frank, Huai, Yiming, Chen, Eugene, Chang, Jia-Hwang
• Application Number:
  US12/017,532
• Publication Number:
  US 20090185410A1
• Time in Patent Office: Days
• US Class Current: 365/158
• CPC Class Codes: G11C 11/16 using elements in which the storage effect is based on magnetic spin effect
• CPC Class Codes: G11C 11/1653 Address circuits or decoders
• CPC Class Codes: G11C 11/1659 Cell access
• CPC Class Codes: G11C 11/1673 Reading or sensing circuits or methods
• CPC Class Codes: G11C 11/1675 Writing or programming circuits or methods

Abstract

A magnetic memory cell and a magnetic memory incorporating the cell are described. The magnetic memory cell includes at least one magnetic element and a plurality of unidirectional polarity selection devices. The magnetic element(s) are programmable using write current(s) driven through the magnetic element. The unidirectional polarity selection devices are connected in parallel and such that they have opposing polarities. The magnetic memory may include a plurality of magnetic storage cells, a plurality of bit lines corresponding to the plurality of magnetic storage cells, and a plurality of source lines corresponding to the plurality of magnetic storage cells.

Claims

1. A magnetic memory cell comprising:

at least one magnetic element, the at least one magnetic element being programmable using at least one write current driven through the magnetic element; and

a plurality of unidirectional polarity selection devices coupled with the at least one magnetic element, the plurality of unidirectional polarity selection devices connected in parallel, the plurality of unidirectional polarity selection devices being coupled to have opposing polarity.

2. The magnetic memory cell of claim 1 wherein the plurality of unidirectional polarity selection devices further includes a pair of diodes.

3. The magnetic memory cell of claim 2 wherein the pair of diodes are coupled such that current is driven through only one diode of the pair of diodes at a time.

4. The magnetic memory cell of claim 2 wherein the pair of diodes includes a pair of vertical diodes.

5. A magnetic memory comprising:

a plurality of magnetic storage cells, each of the plurality of magnetic storage cells including at least one magnetic element and a plurality of unidirectional polarity selection devices coupled with the at least one magnetic element, the at least one magnetic element being programmable using at least one write current driven through the magnetic element, the plurality of unidirectional polarity selection devices connected in parallel, the plurality of unidirectional polarity selection devices being coupled to have opposing polarity;

a plurality of bit lines corresponding to the plurality of magnetic storage cells; and

a plurality of source lines corresponding to the plurality of magnetic storage cells.

6. The magnetic memory of claim 5 wherein the plurality of bit lines are coupled with the at least one magnetic element of the plurality of storage cells.

7. The magnetic memory of claim 5 wherein the plurality of unidirectional polarity selection devices further includes a pair of diodes.

8. The magnetic memory of claim 6 wherein the pair of diodes are coupled such that current is driven through only one diode of the pair of diodes at a time.

9. The magnetic memory of claim 6 wherein the pair of diodes includes a pair of vertical diodes.

10. The magnetic memory of claim 6 wherein the plurality of word lines further includes a first word line and a second word line for each of a portion of the plurality of magnetic storage cells, the first word line corresponding to a first unidirectional polarity selection device having a first polarity, the second word line corresponding to a second unidirectional polarity selection device having a second polarity opposite to the first polarity.

11. The magnetic memory of claim 10 further comprising:

a plurality of clamping devices coupled with each of the plurality of magnetic storage cells, each of the plurality of clamping devices being coupled in parallel with the plurality of unidirectional polarity selection devices and being separately activated.

12. A method for providing a magnetic memory cell comprising:

providing a plurality of unidirectional polarity selection devices, the plurality of unidirectional polarity selection devices connected in parallel, the plurality of unidirectional polarity selection devices being coupled to have opposing polarity; and

providing at least one magnetic element coupled with the plurality of unidirectional polarity selection devices, the at least one magnetic element being programmable using at least one write current driven through the magnetic element.

13. The method of claim 12 wherein the plurality of unidirectional polarity selection devices further includes a pair of diodes.

14. The method of claim 13 wherein the pair of diodes are coupled such that current is driven through only one diode of the pair of diodes at a time.

15. The method of claim 12 wherein the pair of diodes includes a pair of vertical diodes.

16. A method for providing a magnetic memory comprising:

providing a plurality of magnetic storage cells, each of the plurality of magnetic storage cells including at least one magnetic element and a plurality of unidirectional polarity selection devices coupled with the at least one magnetic element, the at least one magnetic element being programmable using at least one write current driven through the magnetic element, the plurality of unidirectional polarity selection devices connected in parallel, the plurality of unidirectional polarity selection being coupled to have opposing polarity;

providing a plurality of bit lines corresponding to the plurality of magnetic storage cells; and

a plurality of source lines corresponding to the plurality of magnetic storage cells.

17. The method of claim 16 wherein the plurality of unidirectional polarity selection devices further includes a pair of diodes.

18. The method of claim 16 wherein the pair of diodes are coupled such that current is driven through only one diode of the pair of diodes at a time.

19. The method of claim 18 wherein the pair of diodes includes a pair of vertical diodes.

20. The method of claim 16 wherein the plurality of word lines further includes a first word line and a second word line for each of a portion of the plurality of magnetic storage cells, the first word line corresponding to a first unidirectional polarity selection device having a first polarity, the second word line corresponding to a second unidirectional polarity selection device having a second polarity opposite to the first polarity.

21. The method of claim 20 further comprising:

providing a plurality of clamping devices coupled with each of the plurality of magnetic storage cells, each of the plurality of clamping devices being coupled in parallel with the plurality of unidirectional polarity selection devices and being separately activated.