IP Library Granted Patent US 9,812,497
Granted Patent B2
US 9,812,497 · App. 13/070,714 · Granted Nov 7, 2017

Method for manufacturing magnetic storage device, and magnetic storage device

Inventor: Akiyoshi Hatada (Yokohama, JP)
Assignee: FUJITSU SEMICONDUCTOR LIMITED
H01L27/228H01L43/12
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Quick Facts
Patent No.
US 9,812,497
App. No.
13/070,714
Granted
Nov 7, 2017
Kind
B2
Abstract

A lower conductive film is formed over a substrate. A first insulating film is formed in the lower conductive film. An opening which reaches the lower conductive film is formed in the first insulating film. An MTJ multilayer film having a magnetization free layer, a tunnel barrier layer and a magnetization fixed layer is deposited over the lower conductive film in the opening and over the first insulating film. An upper electrode is formed over the MTJ multilayer film. By removing the portion of the MTJ multilayer film deposited over the first insulating film, an MTJ device composed of the portion of the MTJ multilayer film which has remained in the opening is formed. A lower electrode composed of the lower conductive film is formed under the MTJ device by removing at least a part of the first insulating film, and a part of the lower conductive film.

Claims (34)

1. A method for manufacturing a magnetic storage device comprising:

forming lower conductive film over a substrate;

forming a first insulating film over the lower conductive film;

forming an opening in the first insulating film, the opening reaching the lower conductive film and the lower conductive film being exposed through the opening;

depositing an MTJ multilayer film including a magnetization free layer, a tunnel barrier layer and a magnetization fixed layer over the lower conductive film in the opening and over the first insulating film;

forming, by removing the MTJ multilayer film deposited over the first insulating film, an MTJ device including the MTJ multilayer film which has remained in the opening;

forming, by partially removing the first insulating film, a protection film including the first insulating film around the MTJ device, the protection film protecting a side surface of the MTJ device; and

forming, by partially removing the lower conductive film, a lower electrode including the lower conductive film under the MTJ device and the protection film, an outer periphery of the lower electrode matching an outer periphery of the protection film.

2. The method for manufacturing the magnetic storage device according to claim 1 , wherein

the depositing the MTJ multilayer film further comprises depositing an upper conductive film over the magnetization free layer, the tunnel barrier layer and the magnetization fixed layer in the opening; and

the forming the MTJ device further comprises forming, by removing at least a portion of the upper conductive film deposited over the first insulating film, an upper electrode including a remaining portion of the upper conductive film which is maintained over the MTJ device.

3. The method for manufacturing the magnetic storage device according to claim 1 , wherein the forming the lower electrode comprises:

forming a mask pattern which covers the MTJ device over the first insulating film;

removing the first insulating film and the lower conductive film with the mask pattern used as a mask; and

removing the mask pattern.

4. The method for manufacturing the magnetic storage device according to claim 3 , wherein:

a surface of the substrate comprises an insulating region and a conductive region;

in the forming the opening, the opening is formed in the insulating region; and

the mask pattern covers a region partially overlapping the conductive region.

5. The method for manufacturing the magnetic storage device according to claim 1 , wherein:

in the depositing the MTJ multilayer film, a first film of the MTJ multilayer film, which is disposed closer to the substrate than the tunnel barrier layer is, is formed between the lower conductive film and the first insulating film, and a second film of the MTJ multilayer film, which is disposed at an opposite side of the tunnel barrier layer from the first film, is formed over the first insulating film; and

in the forming the lower electrode, the first film of the MTJ multilayer film is patterned into a same planar shape as the lower electrode.

6. The method for manufacturing the magnetic storage device according to claim 1 , wherein a side surface of the opening has a reverse-tapered shape.

7. The method for manufacturing the magnetic storage device according to claim 1 , wherein:

the first insulating film comprises a lower part and an upper part whose etching properties are different from each other; and

in the forming the opening, after the opening is formed in the upper part, an eave-like part in which the upper part projects toward a center of the opening is formed by etching the lower part in a thickness direction and in a lateral direction with the upper part serving as an etching mask.

8. A method for manufacturing a magnetic storage device comprising:

forming lower conductive film over a substrate;

forming a first insulating film over the lower conductive film;

forming an opening in the first insulating film, the opening reaching the lower conductive film and the lower conductive film being exposed through the opening;

depositing an MTJ multilayer film including a magnetization free layer, a tunnel barrier layer and a magnetization fixed layer over the lower conductive film in the opening and over the first insulating film;

forming, by removing the MTJ multilayer film deposited over the first insulating film, an MTJ device including the MTJ multilayer film which has remained in the opening;

removing the first insulating film, the lower conductive film being exposed in a region where the first insulating film has been removed; and

forming, by removing the exposed lower conductive film, a lower electrode including the lower conductive film remaining under the MTJ device.

Assignments (2)
CHANGE OF ADDRESS Recorded Dec 23, 2016
From: FUJITSU SEMICONDUCTOR LIMITED
To: FUJITSU SEMICONDUCTOR LIMITED
Reel/Frame 041188/0401 →
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Mar 25, 2011
From: HATADA, AKIYOSHI
To: FUJITSU SEMICONDUCTOR LIMITED
Reel/Frame 026020/0197 →
Priority Claims (1)
JP 2010-107187 · May 7, 2010 · national
Continuity (1)
Related Publication 20110272770A1 · Nov 10, 2011