SELF CONTACTING BIT LINE TO MRAM CELL

• US 20150021724A1
• Filed: 04/11/2012
• Published: 01/22/2015
• Est. Priority Date: 04/11/2011
• Status: Abandoned Application

• Current Assignee: III Holdings 1, LLC (Intellectual Ventures LLC)
• Original Assignee: MagSil Corporation
• Inventors: Mani, Krishnakumar
• Application Number:
  US13/444,805
• Publication Number:
  US 20150021724A1
• Time in Patent Office: Days
• US Class Current: 257/421
• CPC Class Codes: G11C 11/161 details concerning the memory cell structure, e.g. the layers of the ferromagnetic memory cell
• CPC Class Codes: H10B 61/00 Magnetic memory devices, e.g. magnetoresistive RAM [MRAM] devices
• CPC Class Codes: H10N 50/01 Manufacture or treatment
• CPC Class Codes: H10N 50/10 Magnetoresistive devices

Abstract

Embodiments of the invention disclose magnetic memory cell configurations in which a magnetic storage structure is coupled to an upper metal layer with minimal overlay margin. This greatly reduces a size of the memory cell.

Claims

1. A magnetic memory cell, comprising:

a memory element; and

an upper metal layer;

wherein the memory element is directly coupled to the upper metal layer without the use of a via.

2. The magnetic memory cell of claim 1, wherein the memory element comprises a Magnetic Tunnel Junction (MTJ) stack.

3. The magnetic memory cell of claim 2, wherein a size of the MTJ stack is f and a width of the upper metal layer is f+2∂

, where ∂

is an overlay margin for the upper metal layer.

4. The magnetic memory cell of claim 2, further comprising dielectric sidewalls formed on opposed sides of the MTJ stack.

5. The magnetic memory cell of claim 1, further comprising:

a hard mask layer etched and patterned to sit atop the memory element.

6. The magnetic memory cell of claim 5, wherein the memory element comprises a Magnetic Tunnel Junction (MTJ) stack.

7. The magnetic memory cell of claim 5, wherein a size of the MTJ stack is f and a width of the upper metal layer is f+2∂

, where ∂

is an overlay margin for the upper metal layer.

8. The magnetic memory cell of claim 5, wherein the hard mask layer comprises a material selected from the group consisting of titanium nitride, titanium, aluminum, and tantalum.

9-11. -11. (canceled)

12. A magnetic memory cell, comprising:

a magnetic memory element;

a read lead directly coupled to a lower end of the magnetic memory element;

a bit line directly coupled to an upper end of the magnetic memory element; and

a word line positioned under the magnetic memory element such that the read lead passes between the word line and the magnetic memory element.

13. The magnetic memory cell of claim 12, wherein a size of the magnetic storage element is f and a width of the bit line is f+2∂

, where ∂

is an overlay margin for the bit line.

14. The magnetic memory cell of claim 12, wherein the magnetic memory element comprises a Magnetic Tunnel Junction (MTJ) stack.

15. The magnetic memory cell of claim 13, further comprising dielectric sidewalls formed on sides of the MTJ stack.

16. The magnetic memory cell of claim 12, further comprising a hard mask layer etched and patterned to sit atop the memory element.

17. A magnetic memory cell, comprising:

a Magnetic Tunnel Junction (MTJ) stack including a plurality of layers;

a read lead directly coupled to a lower layer of the MTJ stack;

a bit line directly coupled to an upper layer of the MTJ stack; and

a word line positioned under the MTJ stack such that the read lead passes between the word line and the MTJ stack.

18. The magnetic memory cell of claim 17, wherein a size of the MTJ stack is f and a width of the bit line is f+2∂

, where ∂

is an overlay margin for the bit line.

19. The magnetic memory cell of claim 17, wherein the plurality of layers of the MTJ stack comprises a pin layer, a tunnel oxide layer, and a fixed layer.

20. The magnetic memory cell of claim 17, further comprising dielectric sidewalls formed on sides of the MTJ stack.

21. The magnetic memory cell of claim 17, further comprising a hard mask layer etched and patterned to sit atop the MTJ stack.

22. The magnetic memory cell of claim 21, wherein a size of the MTJ stack is f and a width of the upper metal layer is f+2∂

, where ∂

is an overlay margin for the upper metal layer.

23. The magnetic memory cell of claim 21, wherein the hard mask layer comprises a material selected from the group consisting of titanium nitride, titanium, aluminum, and tantalum.