Magnetoresistive element and manufacturing method thereof

• US 9,620,561 B2
• Filed: 02/20/2015
• Issued: 04/11/2017
• Est. Priority Date: 09/05/2014
• Status: Active Grant

• Current Assignee: Kioxia Corporation
• Original Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation)
• Inventors: Nagase, Toshihiko, Watanabe, Daisuke, Eeh, Youngmin, Ueda, Koji, Sawada, Kazuya, Nagamine, Makoto
• Primary Examiner(s): Lee, Calvin
• Application Number:
  US14/627,552
• Publication Number:
  US 20160072046A1
• Time in Patent Office: 781 Days
• Field of Search: 438 59, 257421-422
• CPC Class Codes: H01L 21/67709 using magnetic elements
• CPC Class Codes: H01L 29/82 controllable by variation of the magnetic field applied to the device
• 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

According to one embodiment, a magnetoresistive element is disclosed. The magnetoresistive element includes an underlayer containing aluminum (Al), nitrogen (N) and X. The X is an element other than Al and N. A first magnetic layer is provided on the underlayer. A nonmagnetic layer is provided on the first magnetic layer. A second magnetic layer is provided on the nonmagnetic layer.

Claims

1. A method of manufacturing a magnetoresistive element, comprising:

forming a crystalline underlayer containing aluminum (Al), nitrogen (N) and X, wherein the X is an element other than Al and N;

forming a first magnetic layer on the crystalline underlayer;

forming a nonmagnetic layer on the first magnetic layer;

forming a second magnetic layer on the nonmagnetic layer; and

forming a buffer layer, wherein the crystalline underlayer is formed on the buffer layer.

2. The method according to claim 1, wherein the X contains titanium (Ti), zirconium (Zr), hafnium (Hf), vanadium (V), niobium (Nb), tantalum (Ta), chromium (Cr), molybdenum (Mo) or tungsten (W).

3. The method according to claim 1, wherein the forming the crystalline underlayer is carried out in an atmosphere containing nitrogen, and is carried out by using a sputtering process with a target containing Al and the X.

4. The method according to claim 3, wherein the forming the underlayer further comprises subjecting the crystalline underlayer to heat treatment after the sputtering process.

5. The method according to claim 3, wherein the buffer layer contains at least one of Ta, Ti, W, Zr, Hf and Cr.

6. A magnetoresistive element comprising:

a crystalline underlayer containing aluminum (Al), nitrogen (N) and X, wherein the X is an element other than Al and N;

a first magnetic layer provided on the crystalline underlayer;

a nonmagnetic layer provided on the first magnetic layer;

a second magnetic layer provided on the nonmagnetic layer; and

a buffer layer, wherein the crystalline underlayer is formed on the buffer layer.

7. The magnetoresistive element according to claim 6, wherein the X contains titanium (Ti), zirconium (Zr), hafnium (Hf), vanadium (V), niobium (Nb), tantalum (Ta), chromium (Cr), molybdenum (Mo) or tungsten (W).

8. The magnetoresistive element according to claim 6, wherein the crystalline underlayer does not contain a metallic state of Al.

9. The magnetoresistive element according to claim 6, wherein the nonmagnetic layer does not contain a metallic state of Al.

10. The magnetoresistive element according to claim 6, wherein the crystalline underlayer further contains a compound of Al and the X.

11. The magnetoresistive element according to claim 6, wherein the crystalline underlayer further contains a compound of N and the X.

12. The magnetoresistive element according to claim 6, wherein the buffer layer contains at least one of Ta, Ti, W, Zr, Hf and Cr.

13. The magnetoresistive element according to claim 6, wherein concentration of the X in the crystalline underlayer is equal to or greater than 10 at. %.

14. The magnetoresistive element according to claim 6, wherein the crystalline underlayer comprises a first region containing a compound of Al and N and second regions containing a compound of the X and N, the first region is different from the second regions in composition, and part of the second regions is surrounded by the first region.

15. The magnetoresistive element according to claim 14, wherein the second regions have pillar shapes.

16. The magnetoresistive element according to claim 15, wherein side surfaces of the second regions are surrounded by the first region.

17. A magnetoresistive element comprising:

an underlayer comprising (Al₅₀N₅₀)z(TiyN_100-Y)_100-Z, where 50≦

Y≦

55;

a first magnetic layer provided on the underlayer;

a nonmagnetic layer provided on the first magnetic layer;

a second magnetic layer provided on the nonmagnetic layer; and

a buffer layer, wherein the crystalline underlayer is formed on the buffer layer.