Switching film structure for magnetic random access memory (MRAM) cell

• US 9,461,094 B2
• Filed: 07/17/2014
• Issued: 10/04/2016
• Est. Priority Date: 07/17/2014
• Status: Active Grant

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Qualcomm, Inc.
• Inventors: Li, Xia, Chen, Wei-Chuan, Lu, Yu, Lee, Kangho, Kang, Seung Hyuk
• Primary Examiner(s): Hoang, Huan
• Application Number:
  US14/334,554
• Publication Number:
  US 20160020250A1
• Time in Patent Office: 810 Days
• Field of Search: 365/158, 365/171, 365/173, 365/175
• US Class Current: 1/1
• 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 11/1673 Reading or sensing circuits or methods
• CPC Class Codes: G11C 11/1675 Writing or programming circuits or methods
• CPC Class Codes: G11C 2213/73 Array where access device function, e.g. diode function, being merged with memorizing function of memory element
• CPC Class Codes: H10B 61/10 comprising components having two electrodes, e.g. diodes or MIM elements
• CPC Class Codes: H10B 61/22 of the field-effect transistor [FET] type
• CPC Class Codes: H10N 50/10 Magnetoresistive devices

Abstract

An MRAM cell may include a magnetic tunneling junction (MTJ). The MTJ includes a pin layer, a barrier layer, a free layer, and a capping layer. The MRAM cell further includes a bidirectional diode selector, directly coupled to an electrode of the MTJ, to enable access to the MTJ.

Claims

1. A magnetic random access memory (MRAM) cell, comprising:

a magnetic tunneling junction (MTJ) comprising a pin layer, a barrier layer, a free layer, and a capping layer; and

a bidirectional diode selector, comprising a selector electrode directly coupled to the pin layer, and a selector layer directly coupled to the capping layer of the MTJ, to enable access to the MTJ.

2. The MRAM cell of claim 1, in which the selector electrode of the bidirectional diode selector directly supports the pin layer of the MTJ.

3. The MRAM cell of claim 2, in which the selector layer of the bidirectional diode selector is self-aligned to an MTJ electrode.

4. The MRAM cell of claim 1, in which the selector layer of the bidirectional diode selector is directly on the capping layer of the MTJ.

5. The MRAM cell of claim 1, in which the selector layer of the bidirectional diode selector comprises a conductive film.

6. The MRAM cell of claim 1, in which the bidirectional diode selector has a non-linear selector characteristic.

7. The MRAM cell of claim 1, within an MRAM cell array, coupled to a plurality of access transistors.

8. The MRAM cell of claim 1, within a first MRAM layer, stacked on another MRAM layer.

9. The MRAM cell of claim 1 integrated into a mobile phone, a set top box, a music player, a video player, an entertainment unit, a navigation device, a computer, a hand-held personal communication systems (PCS) unit, a portable data unit, and/or a fixed location data unit.

10. A magnetic random access memory (MRAM) cell, comprising:

a magnetic tunneling junction (MTJ) comprising a pin layer, a barrier layer, a free layer, and a capping layer; and

a bi-directionally diode selector, directly coupled to one of the pin layer, the barrier layer, the free layer or the capping layer of the MTJ, in which the bi-directionally diode selector is within an electrode via of the MTJ.

11. A magnetic random access memory (IVIRAM) cell, comprising:

a magnetic tunneling junction (MTJ) comprising a pin layer, a barrier layer, a free layer, and a capping layer; and

means for bi-directionally accessing the MTJ, in which the means for bi-directionally accessing comprises a selector electrode directly coupled to the pin layer, and a selector layer directly coupled to the capping layer of the MTJ.

12. The MRAM cell of claim 11, in which the accessing means is directly to the capping layer of the MTJ.

13. The MRAM cell of claim 11, in which the accessing means has a non-linear selector characteristic.

14. The MRAM cell of claim 11 integrated into a mobile phone, a set top box, a music player, a video player, an entertainment unit, a navigation device, a computer, a hand-held personal communication systems (PCS) unit, a portable data unit, and/or a fixed location data unit.

15. A method for storing data in a magnetic random access memory (MRAM) cell, comprising:

a step for storing a memory bit in a magnetic tunneling junction (MTJ) device, the MTJ device comprising a pin layer, a barrier layer, a free layer, and a capping layer; and

a step for accessing the MTJ device with a selector electrode directly coupled to the pin layer, and a selector layer directly coupled to the capping layer of the MTJ.

16. The method of claim 15, further comprising a step for integrating the MRAM cell into a mobile phone, a set top box, a music player, a video player, an entertainment unit, a navigation device, a computer, a hand-held personal communication systems (PCS) unit, a portable data unit, and/or a fixed location data unit.

17. A method for storing data in a magnetic random access memory (MRAM) cell, comprising:

storing a memory bit in a magnetic tunneling junction (MTJ) device, the MTJ device comprising a pin layer, a barrier layer, a free layer, and a capping layer; and

accessing the MTJ device with a selector electrode directly coupled to the pin layer, and a selector layer directly coupled to the capping layer of the MTJ.

18. The method of claim 17, further comprising integrating the MRAM cell into a mobile phone, a set top box, a music player, a video player, an entertainment unit, a navigation device, a computer, a hand-held personal communication systems (PCS) unit, a portable data unit, and/or a fixed location data unit.