Tungsten-Vanadium Alloy Spin-Orbit Torque Switching Device

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Solution Overview

Problem

Existing spin-orbit torque-based magnetic tunnel junction devices face a challenge in maintaining perpendicular magnetic anisotropy while enhancing spin-orbit torque efficiency, as previous structures result in energy loss of perpendicular magnetic anisotropy.

Innovation Solution

A method involving the deposition of a tungsten-vanadium alloy on tungsten, optimized in composition range and heat treatment conditions, to form a spin-orbit torque-based switching device with perpendicular magnetic anisotropy characteristics, where the tungsten-vanadium alloy acts as a conductive layer for in-plane current and improves spin-orbit torque efficiency without losing perpendicular magnetic anisotropy energy.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Power

If a heterogeneous additional layer is formed between the spin torque generating layer and the magnetization free layer to improve spin-orbit torque efficiency, then spin-orbit torque efficiency is improved, but perpendicular magnetic anisotropy energy is lost

Engineering Contradiction:
Improvespin-orbit torque efficiencyVSAvoidperpendicular magnetic anisotropy energy
Core Design Contradiction:
PowerVSLoss of energy

Solution Approach 1:

The patent changes the material composition parameters by forming a tungsten-vanadium alloy layer with specific vanadium concentration (5-50 at%) instead of using a heterogeneous additional layer. This parameter change allows achieving high spin-orbit torque efficiency while preserving perpendicular magnetic anisotropy energy, as the alloy layer maintains the necessary magnetic properties while providing the desired spin Hall effect.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent uses a composite tungsten-vanadium alloy material that combines the advantages of both tungsten (high spin Hall angle) and vanadium (maintains PMA). This composite approach allows the layer to function as both a spin torque generating layer and a layer that maintains perpendicular magnetic anisotropy, eliminating the need for separate heterogeneous layers that would cause energy loss.

Inventive Principle:
Principle #40Composite materials

2Power

If the vanadium composition in tungsten-vanadium alloy is increased to improve spin-orbit torque efficiency, then spin-orbit torque efficiency increases, but perpendicular magnetic anisotropy may be compromised

Engineering Contradiction:
Improvespin-orbit torque efficiencyVSAvoidperpendicular magnetic anisotropy stability
Core Design Contradiction:
PowerVSStability of the object's composition

Solution Approach 1:

The patent establishes an optimal parameter range for vanadium composition (5-50 at%) that balances spin-orbit torque efficiency and perpendicular magnetic anisotropy stability. Within this range, the alloy achieves sufficient spin Hall angle for high efficiency while maintaining the perpendicular magnetic anisotropy necessary for stable operation. The patent further optimizes this range based on heat treatment temperature to achieve the best balance.

Inventive Principle:
Principle #35Parameter changes

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

The approach increases spin-orbit torque efficiency by up to 40% compared to conventional devices, maintaining perpendicular magnetic anisotropy and reducing the current required for magnetization reversal, with optimal vanadium composition and heat treatment temperatures.

Implementation Method 1

a spin-orbit torque phenomenon in which switching of a magnetization free layer is induced using a spin Hall effect or a Rashba effect that occurs when current flows in a parallel direction in the plane of a spin torque generating layer adjacent to the magnetization free layer

Methodology Applied
Scientific EffectSpin Hall Effect: Hall Effect

Implementation Method 2

The magnetic tunnel junction 100 stores information using a tunneling magneto-resistance (TMR) phenomenon in which an electric resistance value of tunneling current passing through an insulating layer is changed according to the relative magnetization directions of the magnetization free layer and the magnetization pinned layer

Methodology Applied
Scientific EffectTunneling Magneto-Resistance: Magnetoresistance

Implementation Method 3

A method involving the deposition of a tungsten-vanadium alloy on tungsten, optimized in composition range and heat treatment conditions, to form a spin-orbit torque-based switching device with perpendicular magnetic anisotropy characteristics

Methodology Applied
Scientific EffectHeat Treatment: Heat Treatment

Data Source

PatentEP3809413B1Method of fabricating a spin-orbit torque-based switching device
Publication Date: 2023.09.06 KOREA UNIV RES & BUSINESS FOUND
  • EP3809413B1 patent drawingFigure 1~2
  • EP3809413B1 patent drawingFigure 3~4A
  • EP3809413B1 patent drawingFigure 4B~5A

AI summary

The present disclosure relates to a spin-orbit torque-based switching device and a method of fabricating the same. The spin-orbit torque-based switching device of the present disclosure includes a spin torque generating layer provided with a tungsten-vanadium alloy thin film exhibiting perpendicular magnetic anisotropy (PMA) characteristics and a magnetization free layer formed on the spin torque generating layer.