Magnetoresistive Memory Element and Method of Fabricating Same

Patent metadata

Field	Value
Publication number	US-2016013401-A1
Application number	US-201514860657-A
Country	US
Kind code	A1
Filing date	Sep 21, 2015
Priority date	Jun 10, 2011
Publication date	Jan 14, 2016
Grant date	—

Abstract

A magnetoresistive memory element (for example, a spin-torque magnetoresistive memory element), includes first and second dielectric layers, wherein at least one of the dielectric layers is a magnetic tunnel junction. The memory element also includes a free magnetic layer having a first surface in contact with the first dielectric layer and a second surface in contact with the second dielectric layer. The free magnetic layer, which is disposed between the first and second dielectric layers, includes (i) a first high-iron interface region located along the first surface of the free magnetic layer, wherein the first high-iron interface region has at least 50% iron by atomic composition, and (ii) a first layer of ferromagnetic material adjacent to the first high-iron interface region, the first high-iron interface region between the first layer of ferromagnetic material and the first surface of the free magnetic layer.

First claim

What is claimed is:

1 . A magnetoresistive memory element, comprising:
a first dielectric layer; a second dielectric layer, wherein at least one of the first and second dielectric layers is a magnetic tunnel junction; and a free magnetic layer, disposed between the first and second dielectric layers, having a first surface in contact with the first dielectric layer and a second surface in contact with the second dielectric layer, wherein, between the first surface and the second surface, the free magnetic layer includes:
a first high-iron interface region located along the first surface of the free magnetic layer, wherein the first high-iron interface region has at least 50% iron by atomic composition, and
a first layer of ferromagnetic material adjacent to the first high-iron interface region, the first high-iron interface region between the first layer of ferromagnetic material and the first surface of the free magnetic layer.

2 . The magnetoresistive memory element of claim 1 , wherein the first high-iron interface region includes a continuous atomic layer of iron or a discontinuous atomic layer of iron.

3 . The magnetoresistive memory element of claim 1 , wherein the first high-iron interface region is or includes a high-iron alloy comprising iron and ferromagnetic material.

4 . The magnetoresistive memory element of claim 1 , wherein the first dielectric layer provides a first magnetic tunnel junction and/or the second dielectric layer provides a second magnetic tunnel junction.

5 . The magnetoresistive memory element of claim 1 , wherein the free magnetic layer includes perpendicular magnetic anisotropy.

6 . The magnetoresistive memory element of claim 1 , wherein the free magnetic layer further includes:
a second high-iron interface region located along the second surface of the free magnetic layer, wherein the second high-iron interface region has at least 50% iron by atomic composition.

7 . The magnetoresistive memory element of claim 6 , wherein the second high-iron interface region includes a continuous atomic layer of iron or a discontinuous atomic layer of iron.

8 . The magnetoresistive memory element of claim 1 , wherein the free magnetic layer further includes:
an insertion layer adjacent first layer of ferromagnetic material, wherein the insertion layer includes tantalum or ruthenium.

9 . The magnetoresistive memory element of claim 7 , wherein the first insertion layer includes a tantalum-rich ferromagnetic alloy.

10 . The magnetoresistive memory element of claim 7 , wherein the first insertion layer includes a continuous layer or a discontinuous layer.

11 . A magnetoresistive memory element, comprising:
a first dielectric layer having a first magnetoresistance; a second dielectric layer having a second magnetoresistance, wherein the second magnetoresistance is zero; and a free magnetic layer, disposed between the first and second dielectric layers, having a first surface in contact with the first dielectric layer and a second surface in contact with the second dielectric layer, wherein, between the first surface and the second surface, the free magnetic layer includes:
a first high-iron interface region located along (i) the first surface of the free magnetic layer or (ii) the second surface of the free magnetic layer, wherein the first high-iron interface region has at least 50% iron by atomic composition, and
a first layer of ferromagnetic material adjacent to the first high-iron interface region.

12 . The magnetoresistive memory element of claim 11 , wherein the first high-iron interface region includes a continuous atomic layer of iron or discontinuous atomic layer of iron.

13 . The magnetoresistive memory element of claim 11 , wherein the first high-iron interface region is or includes a high-iron alloy comprising iron and ferromagnetic material.

14 . The magnetoresistive memory element of claim 11 , wherein:
the first high-iron interface region is located along the second surface of the free magnetic layer and the free magnetic layer includes perpendicular magnetic anisotropy at an interface between the free magnetic layer and the second dielectric layer.

15 . The magnetoresistive memory element of claim 11 , wherein:
the first high-iron interface region is located along the first surface of the free magnetic layer, and wherein the free magnetic layer further includes a second high-iron interface region located along the second surface of the free magnetic layer, wherein the second high-iron interface region has at least 50% iron by atomic composition.

16 . A magnetoresistive memory element, comprising:
a first electrode including one or more ferromagnetic materials; a second electrode including (i) one or more non-ferromagnetic materials and (ii) one or more ferromagnetic materials; a first dielectric layer disposed between the first and the second electrodes, wherein the first dielectric layer is a magnetic tunnel junction; a second dielectric layer disposed between the first and the second electrodes, wherein the one or more non-ferromagnetic materials of the second electrode is/are is disposed on the second dielectric layer; and a free magnetic layer, disposed between the first and second dielectric layers, having a first surface in contact with the first dielectric layer and a second surface in contact with the second dielectric layer, wherein, between the first surface and the second surface, the free magnetic layer includes:
a first high-iron interface region located along (i) the first surface of the free magnetic layer or (ii) the second surface of the free magnetic layer, wherein the first high-iron interface region has at least 50% iron by atomic composition, and
a first layer of ferromagnetic material adjacent to the first high-iron interface region.

17 . The magnetoresistive memory element of claim 16 , wherein the first high-iron interface region includes a continuous atomic layer of iron or a discontinuous atomic layer of iron.

18 . The magnetoresistive memory element of claim 16 , wherein the first high-iron interface region is or includes a high-iron alloy comprising iron and ferromagnetic material.

19 . The magnetoresistive memory element of claim 16 , wherein:
the first high-iron interface region is located along the second surface of the free magnetic layer and the free magnetic layer includes perpendicular magnetic anisotropy at an interface between the free magnetic layer and the second dielectric layer.

20 . The magnetoresistive memory element of claim 16 , wherein:
the first high-iron interface region is located along the first surface of the free magnetic layer, and wherein the free magnetic layer further includes a second high-iron interface region located along the second surface of the free magnetic layer, wherein the second high-iron interface region has at least 50% iron by atomic composition.

21 . The magnetoresistive memory element of claim 20 , wherein:
the free magnetic layer includes perpendicular magnetic anisotropy at an interface between the free magnetic layer and the first dielectric layer.

22 . A method of manufacturing a magnetoresistive memory element on a substrate, comprising:
forming a first dielectric layer; forming a second dielectric layer; and forming a free magnetic layer between the first and second dielectric layers, wherein a first surface of the free magnetic layer is in contact with the first dielectric layer and a sec

Assignees

• Everspin Technologies Inc

Inventors

• Whig Renu
• Sun Jijun
• Rizzo Nicholas
• Slaughter Jon
• Houssameddine Dimitri
• Mancoff Frederick

Classifications

• G11C11/161 Primary

  details concerning the memory cell structure, e.g. the layers of the ferromagnetic memory cell · CPC title

• H01L43/10

  Electricity · mapped topic

• H01L43/12

  Electricity · mapped topic

• H01L43/08 Primary

  Electricity · mapped topic

• H10N50/85

  Materials of the active region · CPC title