Method of manufacturing a magnetoresistive-based device

• US 9,166,155 B2
• Filed: 04/29/2014
• Issued: 10/20/2015
• Est. Priority Date: 08/14/2012
• Status: Active Grant

• Current Assignee: Everspin Technologies Incorporated
• Original Assignee: Everspin Technologies Incorporated
• Inventors: Deshpande, Sarin A., Aggarwal, Sanjeev
• Primary Examiner(s): CULBERT, ROBERTS P
• Application Number:
  US14/264,520
• Publication Number:
  US 20140315329A1
• Time in Patent Office: 539 Days
• Field of Search: 216/22, 483/3
• US Class Current: 1/1
• CPC Class Codes: G11B 5/84 Processes or apparatus specially adapted for manufacturing record carriers
• 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
• CPC Class Codes: H10N 50/80 Constructional details

Abstract

A method of manufacturing a magnetoresistive-based device having magnetic material layers formed between a first electrically conductive layer and a second electrically conductive layer, the magnetic materials layers including a tunnel barrier layer formed between a first magnetic materials layer and a second magnetic materials layer, including removing the first electrically conductive layer and the first magnetic materials layer unprotected by a first hard mask, to form a first electrode and a first magnetic materials, respectively; and removing the tunnel barrier layer, second magnetic materials layer, and second electrically conductive layer unprotected by the second hard mask to form a tunnel barrier, second magnetic materials, and a second electrode.

Claims

1. A method of manufacturing a spin-torque magnetoresistive device, the method comprising:

forming a first electrically conductive electrode layer over a substrate,

forming at least one layer of first magnetic material over the first electrically conductive electrode;

forming a first tunnel barrier layer over the at least one layer of first magnetic material;

forming at least one layer of second magnetic material over the first tunnel barrier layer;

forming a second electrically conductive electrode layer over the at least one layer of second magnetic material;

forming a first hard mask over a portion of the second electrically conductive electrode layer;

performing a first etch, after forming the first hard mask, through the second electrically conductive electrode layer and the at least one layer of second magnetic material to form a second electrically conductive electrode and provide sidewalls of the at least one layer of second magnetic material;

forming a second hard mask over the second electrically conductive electrode and the sidewalls of the at least one layer of second magnetic material;

performing a second etch, after forming the second hard mask, through the first tunnel barrier layer to form the first tunnel barrier, wherein the first tunnel barrier includes sidewalls;

after performing the second etch, forming a third hard mask; and

performing a third etch, after forming the third hard mask, through the first electrically conductive electrode layer to form the first electrically conductive electrode.

2. The method of claim 1 wherein forming the first, second and/or third hard masks include:

depositing a hard mask layer, and

patterning the hard mask layer using a patterned photo resist disposed thereon.

3. The method of claim 1 further including:

forming an encapsulation material, prior to forming the second hard mask, on the;

(i) sidewalls of the at least one layer of second magnetic material and (ii) a portion of the first tunnel barrier layer exposed by the first etch, wherein forming an encapsulation material includes;

depositing material on the (i) sidewalls of the at least one layer of second magnetic material and (ii) a portion of the first tunnel barrier layer exposed by the first etch, and

thereafter, oxidizing the material; and

wherein performing the second etch to form the first tunnel barrier further includes etching through (i) the encapsulation material on the first tunnel barrier layer and (ii) the first tunnel barrier layer.

4. The method of claim 1 wherein the first tunnel barrier layer includes a plurality of layers of magnesium and/or magnesium oxide.

5. The method of claim 1 further including:

forming a second tunnel barrier layer between (i) the at least one layer of second magnetic material and (ii) the second electrically conductive electrode layer, wherein performing the first etch further includes etching through the second tunnel barrier layer to form the second tunnel barrier.

6. The method of claim 5 further including:

forming at least one layer of third magnetic material between (i) the second tunnel barrier layer and (ii) the second electrically conductive electrode layer, wherein performing the first etch further includes etching through the at least one layer of third magnetic material to provide sidewalls of the at least one layer of third magnetic material.

7. The method of claim 1 wherein the at least one layer of first magnetic material and the at least one layer of second magnetic material comprise the same or different types of material.

8. The method of claim 7 wherein the types of material include Nickel (Ni), Iron (Fe), Cobalt (Co), Palladium (Pd), Magnesium (Mg), Manganese (Mn) and alloys thereof.

9. The method of claim 1 wherein performing the second etch or performing the third etch further includes etching through the at least one layer of first magnetic material to provide sidewalls of the at least one layer of first magnetic material.

10. The method of claim 9 further including oxidizing the sidewalls of the at least one layer of first magnetic material prior to performing the third etch.

11. The method of claim 1 wherein forming a third hard mask further includes forming the third hard mask over the sidewalls of the first tunnel barrier.

12. A method of manufacturing a spin-torque magnetoresistive device, the method comprising:

forming a first electrically conductive electrode layer over a substrate,

forming at least one layer of first magnetic material over the first electrically conductive electrode;

forming a first tunnel barrier layer over the at least one layer of first magnetic material;

forming at least one layer of second magnetic material over the first tunnel barrier layer;

forming a metal hard mask layer over the at least one layer of second magnetic material;

performing a first etch through the metal hard mask layer to form a metal hard mask-second electrically conductive electrode;

performing a second etch through the at least one layer of second magnetic material using metal hard mask-second electrically conductive electrode to provide sidewalls of the at least one layer of second magnetic material;

forming a second hard mask over (i) the metal hard mask-second electrically conductive electrode and (ii) the sidewalls of the at least one layer of second magnetic material;

performing a second etch, after forming the second hard mask, through the first tunnel barrier layer to form the first tunnel barrier, wherein the first tunnel barrier includes sidewalls;

after performing the second etch, forming a third hard mask; and

performing a third etch through the first electrically conductive electrode layer to form the first electrically conductive electrode.

13. The method of claim 12 further including:

forming an encapsulation material, prior to forming the second hard mask, on the;

(i) sidewalls of the at least one layer of second magnetic material, and

wherein performing the second etch further includes etching through the encapsulation material and the first tunnel barrier layer to form the first tunnel barrier.

14. The method of claim 12 further including:

forming a second tunnel barrier layer between (i) the at least one layer of second magnetic material and (ii) the metal hard mask layer, wherein performing the first etch further includes etching through the second tunnel barrier layer to form the second tunnel barrier.

15. The method of claim 12 further including:

forming at least one layer of third magnetic material between (i) the second tunnel barrier layer and (ii) the metal hard mask layer, wherein performing the first etch further includes etching through the at least one layer of third magnetic material to provide sidewalls of the at least one layer of third magnetic material.

16. The method of claim 12 wherein the at least one layer of first magnetic material and the at least one layer of second magnetic material comprise the same or different types of material.

17. The method of claim 16 wherein the types of material include Nickel (Ni), Iron (Fe), Cobalt (Co), Palladium (Pd), Magnesium (Mg), Manganese (Mn) and alloys thereof.

18. The method of claim 12 wherein performing the second etch or performing the third etch further includes etching through the at least one layer of first magnetic material to provide sidewalls of the at least one layer of first magnetic material.

19. The method of claim 12 wherein forming the second and/or third hard masks include:

depositing a hard mask layer, and

patterning the hard mask layer using a patterned photo resist disposed thereon.

20. A method of manufacturing a spin-torque magnetoresistive device from:

(i) a first electrically conductive electrode layer disposed over a substrate, (ii) at least one layer of first magnetic material disposed over the first electrically conductive electrode, (iii) a first tunnel barrier layer disposed over the at least one layer of first magnetic material, and (iv) at least one layer of second magnetic material over the first tunnel barrier layer, the method comprising;

forming a metal hard mask layer over the at least one layer of second magnetic material

performing a first etch through the metal hard mask layer to form a metal hard mask-second electrically conductive electrode;

performing a second etch through the at least one layer of second magnetic material using metal hard mask-second electrically conductive electrode to provide sidewalls of the at least one layer of second magnetic material;

forming a second hard mask over (i) the metal hard mask-second electrically conductive electrode and (ii) the sidewalls of the at least one layer of second magnetic material;

performing a second etch through the first tunnel barrier layer using the second hard mask to form the first tunnel barrier, wherein the first tunnel barrier includes sidewalls;

forming a third hard mask over the sidewalls of the first tunnel barrier; and

performing a third etch through the first electrically conductive electrode layer using the third hard mask to form the first electrically conductive electrode.

21. The method of claim 20 wherein performing the third etch further includes etching through the at least one layer of first magnetic material to provide sidewalls of the at least one layer of first magnetic material.

22. The method of claim 20 wherein forming the second and/or third hard masks include:

depositing a hard mask layer, and

patterning the hard mask layer using a patterned photo resist disposed thereon.