Spin Orbit Memory Devices with Reduced Magnetic Moment

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Solution Overview

Problem

The scaling of spin orbit memory devices poses challenges in reducing magnetic stray fields, which affects the operational stability and switching dynamics, particularly due to the high total magnetic moment in synthetic antiferromagnetic (SAF) structures used in perpendicular magnetic tunnel junction (pMTJ) devices.

Innovation Solution

Implementing a first magnet structure with a single layer of platinum between two thin layers of magnet, reducing the total magnetic moment and increasing the tunnel magneto-resistance (TMR) ratio, while minimizing the number of platinum/magnet bilayer repetitions in the SAF structure.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a synthetic antiferromagnetic (SAF) structure with multiple platinum/magnet bilayer repetitions is used in a perpendicular magnetic tunnel junction (pMTJ) device, then the magnetic moment is increased to ensure stable magnetic anisotropy, but the magnetic stray fields increase which adversely affects operational stability and switching dynamics

Engineering Contradiction:

Improvemagnetic anisotropy stabilityVSAvoidmagnetic stray fields

Core Design Contradiction:

ReliabilityVSObject-generated harmful factors

Solution Approach 1:

The patent extracts and removes portions of the SAF structure, specifically reducing the number of platinum/magnet bilayer repetitions from multiple layers to just two layers. This extraction eliminates excess magnetic moment that generates harmful stray fields while retaining enough structure to maintain perpendicular magnetic anisotropy for operational stability

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

The patent changes the structural parameters of the SAF structure by reducing the number of bilayer repetitions to two layers with specific thicknesses (first magnet layer: 0.5-2.0 nm, platinum layer: 0.3-1.0 nm, second magnet layer: 0.5-2.0 nm). This parameter optimization maintains magnetic anisotropy while minimizing magnetic stray fields

Inventive Principle:

Principle #35Parameter changes

2Object-generated harmful factors

If the number of platinum/magnet bilayer repetitions is reduced in the SAF structure, then the magnetic stray fields are reduced, but the tunnel magneto-resistance (TMR) ratio may be affected

Engineering Contradiction:

Improvemagnetic stray fieldsVSAvoidtunnel magneto-resistance ratio

Core Design Contradiction:

Object-generated harmful factorsVSReliability

Solution Approach 1:

The patent optimizes specific thickness parameters of the magnet and platinum layers within the two-bilayer SAF structure to maintain high TMR ratio. By carefully controlling the thickness of each layer (magnet layers: 0.5-2.0 nm, platinum layer: 0.3-1.0 nm), the structure achieves both reduced magnetic stray fields and preserved tunnel magneto-resistance

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The patent uses a composite SAF structure with alternating magnet and platinum layers, where the specific composition and thickness of each material layer are optimized to achieve both low magnetic stray fields and high TMR ratio simultaneously

Inventive Principle:

Principle #40Composite materials

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 effectively reduces the magnetic stray fields, enhancing the switching efficiency and operational stability of spin orbit memory devices by maintaining perpendicular magnetic anisotropy while minimizing undesirable texturing effects and maintaining a high TMR ratio.

Implementation Method 1

spin orbit memory devices including a spin orbit electrode coupled with a compatible Magnetic Tunnel Junction (MTJ) device

Methodology Applied

Scientific EffectSpin orbit torque:

Implementation Method 2

maintaining perpendicular magnetic anisotropy while minimizing undesirable texturing effects

Methodology Applied

Scientific EffectPerpendicular magnetic anisotropy: Anisotropy

Implementation Method 3

increasing the tunnel magneto-resistance (TMR) ratio

Methodology Applied

Scientific EffectTunnel magneto-resistance: Magnetoresistance

Data Source

PatentUS11557629B2Spin orbit memory devices with reduced magnetic moment and methods of fabrication

Publication Date: 2023.01.17 INTEL CORP

AI summary

A spin orbit memory device includes a material layer stack on a spin orbit electrode. The material layer stack includes a magnetic tunnel junction (MTJ) and a synthetic antiferromagnetic (SAF) structure on the MTJ. The SAF structure includes a first magnet structure and a second magnet structure separated by an antiferromagnetic coupling layer. The first magnet structure includes a first magnet and a second magnet separated by a single layer of a non-magnetic material such as platinum. The second magnet structure includes a stack of bilayers, where each bilayer includes a layer of platinum on a layer of a magnetic material such.