Semiconductor device and a manufacturing method thereof

Patent metadata

Field	Value
Publication number	US-2016064654-A1
Application number	US-201514829595-A
Country	US
Kind code	A1
Filing date	Aug 18, 2015
Priority date	Aug 26, 2014
Publication date	Mar 3, 2016
Grant date	—

Abstract

The performances of a semiconductor device are improved. A semiconductor device has a conductive film formed above a semiconductor substrate, a first ferromagnetic film formed over the conductive film, an insulation film formed over the first ferromagnetic film, and a second ferromagnetic film formed over the insulation film. The first ferromagnetic film, the insulation film, and the second ferromagnetic film form a tunnel magnetoresistive effect element. The conductive film is formed of a metal nitride. The first ferromagnetic film contains cobalt, iron, and boron. The insulation film contains magnesium oxide.

First claim

What is claimed is:

1 . A semiconductor device, comprising:
a first conductive film formed above a semiconductor substrate; a first ferromagnetic film formed over the first conductive film; an insulation film formed over the first ferromagnetic film; and a second ferromagnetic film formed over the insulation film, wherein the first ferromagnetic film, the insulation film, and the second ferromagnetic film form a tunnel magnetoresistive effect element, wherein the first conductive film is formed of a metal nitride, wherein the first ferromagnetic film contains cobalt, iron, and boron, and wherein the insulation film contains magnesium oxide.

2 . The semiconductor device according to claim 1 ,
wherein the first conductive film is formed of tantalum nitride.

3 . The semiconductor device according to claim 2 ,
wherein the composition ratio of nitrogen to tantalum in the first conductive film is 0.06 to 0.7.

4 . The semiconductor device according to claim 1 ,
wherein the first ferromagnetic film is formed of a cobalt iron boron film having a (100)-oriented body-centered cubic structure, and wherein the insulation film is formed of a magnesium oxide film having a (100)-oriented rock-salt structure.

5 . The semiconductor device according to claim 1 ,
wherein the first conductive film includes a first region, and a second region situated on a first side of the first region, and wherein the first ferromagnetic film is formed over the first region of the first conductive film.

6 . The semiconductor device according to claim 5 ,
wherein the first conductive film includes a third region situated opposite to the second region across the first region, wherein the first ferromagnetic film includes a fourth region over the first region of the first conductive film, a fifth region formed over the second region of the first conductive film, and a sixth region formed over the third region of the first conductive film, wherein the insulation film is formed over the fourth region of the first ferromagnetic film, over the fifth region of the first ferromagnetic film, and over the sixth region of the first ferromagnetic film, wherein the second ferromagnetic film is formed over the fourth region of the first ferromagnetic film via the insulation film, wherein the fourth region of the first ferromagnetic film has a reversible first magnetization, wherein the fifth region of the first ferromagnetic film has a second magnetization fixed in a first direction, and wherein the sixth region of the first ferromagnetic film has a third magnetization fixed in a second direction in antiparallel with the first direction.

7 . The semiconductor device according to claim 6 , comprising:
a third ferromagnetic film formed under the second region of the first conductive film; and a fourth ferromagnetic film formed under the third region of the first conductive film, wherein in the fifth region of the first ferromagnetic film, the direction of the second magnetization is fixed in the first direction by the third ferromagnetic film, and wherein in the sixth region of the first ferromagnetic film, the direction of the third magnetization is fixed in the second direction by the fourth ferromagnetic film.

8 . The semiconductor device according to claim 7 ,
wherein a current is passed between the third ferromagnetic film and the fourth ferromagnetic film via the fourth region of the first ferromagnetic film, thereby resulting in a change in the direction of the first magnetization of the fourth region of the first ferromagnetic film.

9 . The semiconductor device according to claim 5 ,
wherein the first conductive film includes a seventh region situated opposite to the second region across the first region, wherein the first ferromagnetic film has a reversible fourth magnetization, and wherein a current is passed between the second region of the first conductive film and the seventh region of the first conductive film via the first region of the first conductive film, thereby resulting in a change in the direction of the fourth magnetization of the first ferromagnetic film.

10 . The semiconductor device according to claim 1 ,
wherein the first ferromagnetic film has a reversible fifth magnetization, and wherein the second ferromagnetic film has a sixth magnetization fixed in a third direction.

11 . The semiconductor device according to claim 10 , comprising:
a second conductive film formed over the second ferromagnetic film, wherein a current is passed between the first conductive film and the second conductive film via the first ferromagnetic film, thereby resulting in a change in the direction of the fifth magnetization of the first ferromagnetic film.

12 . The semiconductor device according to claim 1 ,
wherein the first ferromagnetic film has a seventh magnetization fixed in a fourth direction, and wherein the second ferromagnetic film has a reversible eighth magnetization.

13 . A semiconductor device, comprising:
a first conductive film formed above a semiconductor substrate; a first ferromagnetic film formed over the first conductive film; an insulation film formed over the first ferromagnetic film; and a second ferromagnetic film formed over the insulation film, wherein the first ferromagnetic film, the insulation film, and the second ferromagnetic film form a tunnel magnetoresistive effect element, wherein the first conductive film is formed of a metal containing xenon, wherein the first ferromagnetic film contains cobalt, iron, and boron, and wherein the insulation film contains magnesium oxide.

14 . The semiconductor device according to claim 13 ,
wherein the first conductive film is formed of tantalum containing xenon.

15 . A method for manufacturing a semiconductor device, comprising the steps of:
(a) forming a first conductive film above a semiconductor substrate; (b) reforming the surface of the first conductive film; (c) after the step (b), forming a first ferromagnetic film over the first conductive film; (d) forming an insulation film over the first ferromagnetic film; (e) forming a second ferromagnetic film over the insulation film; and (f) after the step (d), performing a heat treatment for crystallization of the first ferromagnetic film and the insulation film, wherein, in the step (a), the first conductive film formed of a metal or a metal nitride is formed, wherein, in the step (c), the first ferromagnetic film containing, cobalt, iron, and boron is formed, and wherein, in the step (d), the insulation film containing magnesium oxide is formed, and wherein the first ferromagnetic film, the insulation film, and the second ferromagnetic film form a tunnel magnetoresistive effect element.

16 . The method for manufacturing a semiconductor device according to claim 15 ,
wherein the step (b) includes the steps of: (b1) oxidizing the surface of the first conductive film; and (b2), after the step (b1), or with the step (b1), etching the surface of the first conductive film.

17 . The method for manufacturing a semiconductor device according to claim 16 ,
wherein, in the step (a), with the semiconductor substrate not exposed to the air, the first conductive film is formed over the semiconductor substrate, wherein, in the step (b1), the semiconductor substrate is exposed to the air, thereby to oxidize the surface of the first conductive film, and wherein, in the step (b2), after the step (b1), the surface of the first conductive film is etched.

Assignees

• Renesas Electronics Corp

Inventors

• Tonegawa Takashi
• Kariyada Eiji
• Kazamatsuri Takayasu

Classifications

• H01L43/12

  Electricity · mapped topic

• H01L43/10

  Electricity · mapped topic

• H01L43/08 Primary

  Electricity · mapped topic

• H10N50/01

  Manufacture or treatment · CPC title

• H10N50/10 Primary

  Magnetoresistive devices · CPC title