Magnetic memory device and method of manufacturing the same

• US 9,735,347 B2
• Filed: 03/09/2016
• Issued: 08/15/2017
• Est. Priority Date: 09/02/2015
• Status: Active Grant

• Current Assignee: Kioxia Corporation
• Original Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation)
• Inventors: Yamakawa, Koji, Natori, Katsuaki, Kanoo, Shinichi, Noma, Kenji
• Primary Examiner(s): Ingham, John C
• Assistant Examiner(s): Haider, Wasiul
• Application Number:
  US15/065,819
• Publication Number:
  US 20170062705A1
• Time in Patent Office: 524 Days
• 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 61/22 of the field-effect transistor [FET] type
• 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
• CPC Class Codes: H10N 50/85 Magnetic active materials

Abstract

According to one embodiment, a magnetic memory device includes: a first magnetic layer; a nonmagnetic layer on the first magnetic layer; a second magnetic layer on the nonmagnetic layer; and an insulator film on the nonmagnetic layer surrounding a side surface of the second magnetic layer. The second magnetic layer has an area of a surface facing the nonmagnetic layer smaller than that of the nonmagnetic layer. The nonmagnetic layer includes a first region that is provided between the first magnetic layer and the insulator film. The first region includes an amorphous state.

Claims

1. A method of manufacturing a magnetic memory device, comprising:

forming a nonmagnetic layer on a first magnetic layer;

forming a second magnetic layer on the nonmagnetic layer;

forming a mask on the second magnetic layer; and

etching the second magnetic layer using a gas;

wherein etching the second magnetic layer includes forming an amorphous state in the nonmagnetic layer.

2. The method of claim 1, wherein the gas of the etching contains neon.

3. The method of claim 1, further comprising:

forming a third magnetic layer;

forming a metal layer on the third magnetic layer;

etching the metal layer using a gas mainly containing neon; and

forming the first magnetic layer on the metal layer.

4. The method of claim 3, wherein the metal layer contains ruthenium.

5. A method of manufacturing a magnetic memory device, comprising:

forming a nonmagnetic layer on a first magnetic layer;

forming a second magnetic layer on the nonmagnetic layer;

forming a first metal layer on the second magnetic layer;

performing annealing after formation of the first metal layer; and

etching the first metal layer and part of the second magnetic layer using a gas mainly containing neon after the annealing.

6. The method of claim 5, wherein an impurity contained in the second magnetic layer diffuses into the first metal layer by the annealing.

7. The method of claim 5, further comprising etching the first magnetic layer using the gas mainly containing neon before formation of the nonmagnetic layer, and wherein etching the first magnetic layer includes forming an amorphous state in the first magnetic layer.

8. The method of claim 7, wherein the first magnetic layer changes from the amorphous state to the crystalline state by the annealing.

9. The method of claim 5, wherein atoms that constitute the first metal layer are implanted into the second magnetic layer by the etching, and an upper portion of the second magnetic layer changes to an amorphous state.

10. The method of claim 9, wherein the metal layer contains one of tantalum and molybdenum.

11. The method of claim 5, further comprising:

forming a third magnetic layer;

forming a second metal layer on the third magnetic layer;

etching the second metal layer using the gas mainly containing neon; and

forming the first magnetic layer on the second metal layer.

12. The method of claim 11, wherein the second metal layer contains ruthenium.

13. The method of claim 5, wherein the first magnetic layer or the second magnetic layer contains cobalt or iron.