Magnetic Tunnel Junction Memory with Inverted Correction Layer

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Solution Overview

Problem

Existing memory devices face challenges in reducing etching damage to magnetic correction layers during the fabrication of Magnetic Tunnel Junction (MTJ) structures, which affects the ability to offset stray magnetic fields, leading to inadequate bias magnetic field reduction and compromised performance.

Innovation Solution

The solution involves locating the magnetic correction layer under the MTJ structure, using a metal oxide under layer with a thickness of less than 10 nm to reduce etching damage, and incorporating a nonmagnetic metal middle layer to improve magnetic anisotropy, thereby enhancing the characteristics of the variable resistance element.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If the magnetic correction layer is located above the MTJ structure, then it can be formed easily, but it suffers from severe etching damage during fabrication

Engineering Contradiction:

Improveease of forming magnetic correction layerVSAvoidetching damage to magnetic correction layer

Core Design Contradiction:

Ease of manufactureVSManufacturing precision

Solution Approach 1:

The magnetic correction layer is inverted from its conventional position above the MTJ structure to a position below the MTJ structure. This inversion protects the magnetic correction layer from etching damage during fabrication while maintaining its functionality in offsetting stray magnetic fields generated by the pinned layer.

Inventive Principle:

Principle #13The other way round (Inversion)

Solution Approach 2:

A metal oxide under layer is introduced as an intermediary between the substrate and the magnetic correction layer. This under layer has a thickness of less than 10 nm and serves as a protective barrier that reduces etching damage to the magnetic correction layer during the fabrication process.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Manufacturing precision

If the metal oxide under layer is made thinner, then etching damage is reduced, but current flow capability may be compromised

Engineering Contradiction:

Improveetching damage reductionVSAvoidcurrent flow capability

Core Design Contradiction:

Manufacturing precisionVSReliability

Solution Approach 1:

The thickness of the metal oxide under layer is optimized to be less than 10 nm. This parameter change allows the layer to be thin enough to reduce etching damage to the magnetic correction layer while remaining thick enough to maintain adequate current flow capability for device operation.

Inventive Principle:

Principle #35Parameter changes

3Device complexity

If the magnetic correction layer is removed, then fabrication is simpler, but stray magnetic field offset capability is lost

Engineering Contradiction:

Improvefabrication complexityVSAvoidstray magnetic field offset capability

Core Design Contradiction:

Device complexityVSReliability

Solution Approach 1:

The magnetic correction layer is inverted to a position below the MTJ structure where it is protected from etching damage. This ensures the layer survives fabrication processes and maintains its essential function of offsetting stray magnetic fields generated by the pinned layer, preventing data storage errors.

Inventive Principle:

Principle #13The other way round (Inversion)

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

This approach reduces etching damage to the magnetic correction layer, improves perpendicular magnetic anisotropy, and enhances the switching current and retention characteristics of the variable resistance element, leading to improved data storage capabilities.

Implementation Method 1

using a metal oxide under layer with a thickness of less than 10 nm to reduce etching damage

Methodology Applied

Scientific EffectEtching damage reduction:

Implementation Method 2

incorporating a nonmagnetic metal middle layer to improve magnetic anisotropy

Methodology Applied

Scientific EffectPerpendicular magnetic anisotropy: Anisotropy

Implementation Method 3

a magnetic correction layer located under the MTJ structure and operates to reduce an influence of a stray magnetic field generated by the pinned layer

Methodology Applied

Scientific EffectStray magnetic field compensation: Magnetic Field

Implementation Method 4

Magnetic Tunnel Junction (MTJ) structure including a free layer having a variable magnetization direction

Methodology Applied

Scientific EffectTunnel magnetoresistance: Magnetoresistance

Data Source

PatentUS9871189B2Electronic device and method for fabricating the same

Publication Date: 2018.01.16 SK HYNIX INC

AI summary

This technology provides an electronic device and a method for fabricating the same. An electronic device in accordance with an implementation of this document includes semiconductor memory, and the semiconductor memory includes a Magnetic Tunnel Junction (MTJ) structure including a free layer having a variable magnetization direction, a pinned layer having a pinned magnetization direction, and a tunnel barrier layer interposed between the pinned layer and the free layer; a magnetic correction layer located under the MTJ structure and operates to reduce an influence of a stray magnetic field generated by the pinned layer; and an under layer located under the magnetic correction layer and including a metal oxide layer.