Magnetic memory and method for manufacturing the same

1. A magnetic memory comprising:

a substrate;

an electrode provided on the substrate;

a first insulating film surrounding a side surface of the electrode, the first insulating film containing oxygen;

a second insulating film provided between the electrode and the first insulating film, the second insulating film surrounding the side surface of the electrode, and the second insulating film containing nitrogen;

a magnetoresistance effect element provided on an upper surface of the electrode, a lower surface of the magnetoresistance effect element being smaller than the upper surface of the electrode;

a third insulating film provided on the magnetoresistance effect element, the third insulating film containing oxygen; and

a first plug penetrating the third insulating film and the first insulating film to reach the substrate,

wherein a portion of the first insulating film and a portion of the third insulating film contact each other around the first plug.

2. The magnetic memory according to claim 1 , wherein an oxygen concentration in the second insulating film is lower than an oxygen concentration in the first insulating film.

3. The magnetic memory according to claim 1 , wherein a nitrogen concentration in the second insulating film is higher than a nitrogen concentration in the first insulating film.

4. The magnetic memory according to claim 1 , further comprising a conductor provided on the second insulating film.

5. The magnetic memory according to claim 4 , wherein the conductor contains a metal which is included in the magnetoresistance effect element.

6. The magnetic memory according to claim 4 , wherein the conductor is further provided on the first insulating film, and a portion of the conductor provided on the first insulating film is thinner than a portion of the conductor provided on the second insulating film.

7. A magnetic memory comprising:

a substrate;

an electrode provided on the substrate;

a first insulating film surrounding a side surface of the electrode, the first insulating film containing oxygen;

a second insulating film provided between the electrode and the first insulating film, the second insulating film surrounding the side surface of the electrode, and the second insulating film containing nitrogen;

a conductor provided on the second insulating film; and

a magnetoresistance effect element provided on an upper surfaced of the electrode, a lower surface of the magnetoresistance effect element being smaller than the upper surface of the electrode,

wherein the conductor is further provided on the first insulating film, and a portion of the conductor provided on the first insulating film is separated from a portion of the conductor provided on the second insulating film.

8. The magnetic memory according to claim 7 , further comprising a plug which penetrates the first insulating film to reach the substrate.

9. The magnetic memory according to claim 8 , wherein the plug contacts the second insulating film.

10. The magnetic memory according to claim 1 , further comprising a second plug which is provided beneath the electrode and which connects the substrate and the electrode.

11. The magnetic memory according to claim 1 , wherein the magnetoresistance effect element includes a first magnetic layer, a tunnel barrier layer provided on the first magnetic layer, and a second magnetic layer provided on the tunnel barrier layer.

12. The magnetic memory according to claim 1 , wherein the portion of the first insulating film and the portion of the third insulating film directly contact around the first plug.

13. The magnetic memory according to claim 1 , wherein the first plug does not penetrate through the second insulating film.