Magnetic memory device and method for fabricating the same

• US 20070241410A1
• Filed: 09/28/2006
• Published: 10/18/2007
• Est. Priority Date: 03/30/2006
• Status: Active Grant

• Current Assignee: Fujitsu Limited
• Original Assignee: Fujitsu Limited
• Inventors: Kobayashi, Kazuo, Sato, Masashige, Umehara, Shinjiro, Ashida, Hiroshi, Ochiai, Takao
• Granted Patent: US 7,535,755 B2
• Time in Patent Office: Days
• US Class Current: 257/379
• CPC Class Codes: B82Y 10/00 Nanotechnology for information processing, storage or transmission, e.g. quantum computing or single electron logic
• 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

Abstract

The magnetic memory device includes a magnetic shield film 48, and a magnetoresistive effect element 62 formed over the magnetic shield film 48 and including a magnetic layer 52, a non-magnetic layer 54 and a magnetic layer 56, in which a magnetization direction of the first magnetic layer or the second magnetic layer is reversed by spin injection, and a second magnetic shield film 68 formed over the side wall of the magnetoresistive effect element 62. Thus, the arrival of the leakage magnetic field from the interconnection near the magnetoresistive effect element 62 can be effectively prevented.

Claims

1. A magnetic memory device comprising:

a first magnetic shield film;

a magnetoresistive effect element formed over the first magnetic shield film and including a first magnetic layer, a non-magnetic layer formed on the first magnetic layer and a second magnetic layer formed on the non-magnetic layer, in which a magnetization direction of the first magnetic layer or the second magnetic layer is reversed by spin injection; and

a second magnetic shield film formed over a side wall of the magnetoresistive effect element.

2. The magnetic memory device according to claim 1, further comprising:

an insulating film formed between the magnetoresistive effect element and the second magnetic shield film.

3. The magnetic memory device according to claim 2, wherein

the insulating film is formed over the side wall and an upper surface of the magnetoresistive effect element.

4. The magnetic memory device according to claim 2, wherein

the insulating film is formed of a moisture-resistant insulating material.

5. The magnetic memory device according to claim 4, wherein

the insulating material contains at least one insulating material selected from the group consisting of SiO, SiN, SiON, AlO, AlN and AlON.

6. The magnetic memory device according to claim 2, wherein

the insulating film is formed in self-alignment with the magnetoresistive effect element.

7. The magnetic memory device according to claim 2, wherein

the second magnetic shield film is formed in self-alignment with the magnetoresistive effect element and the insulating film.

8. The magnetic memory device according to claim 1, further comprising:

a select transistor electrically connected to the magnetoresistive effect element via the first magnetic shield film.

9. A method for fabricating a magnetic memory device comprising the steps of:

forming a first magnetic shield film;

forming over the first magnetic shield film a magnetoresistive effect element including a first magnetic layer, a non-magnetic layer formed on the first magnetic layer and a second magnetic layer formed on the non-magnetic layer; and

forming a second magnetic shield film over a side wall of the magnetoresistive effect element.

10. The method for fabricating a magnetic memory device according to claim 9,

further comprising, after the step of forming the magnetoresistive effect element, the step of forming an insulating film for covering the magnetoresistive effect element,

in the step of forming the second magnetic shield film, the second magnetic shield film is formed over the side wall of the magnetoresistive effect element with the insulating film formed on.

11. The method for fabricating a magnetic memory device according to claim 10,

in the step of forming the insulating film, the insulating film is deposited and etched back to form in self-alignment with the magnetoresistive effect element.

12. The method for fabricating a magnetic memory device according to claim 11, wherein

in the step of forming the magnetoresistive effect element, the magnetoresistive effect element having an upper surface covered with a buffer insulating film is formed, and

in the step of forming the insulating film, the insulating film is etched back, leaving the buffer insulating film over the magnetoresistive effect element.

13. The method for fabricating a magnetic memory device according to claim 9, wherein

in the step of forming the second magnetic shield film, a magnetic material having soft magnetic characteristics and etched back to form the second magnetic shield film in self-alignment with the magnetoresistive effect element.