Spin Device Data Writing Method Using Energy-Pulse Constraint

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Solution Overview

Problem

In spin devices, applying energy to the conducting portion without passing a current in the stacking direction of the device portion can lead to significant resistance decreases, making stable data writing challenging and affecting the screening and manufacturing of magnetoresistance effect elements.

Innovation Solution

A data writing method and magnetoresistance effect element that apply an energy equal to or smaller than a predetermined value, represented by the expression E=(A+BtC)-1+D, to the conducting portion, where A, B, and C are constants determined by the non-magnetic layer, to stabilize data writing and device inspection, with specific constants provided for MgO and MgAl2O4 non-magnetic layers.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If energy is applied to the conducting portion of a spin device, then data writing can be performed, but the resistance of the device portion decreases significantly causing unstable data writing

Engineering Contradiction:

Improvedata writing capabilityVSAvoiddata writing stability

Core Design Contradiction:

ProductivityVSReliability

Solution Approach 1:

The patent applies parameter changes by establishing a quantitative relationship between applied energy and pulse width through the formula E≤(A+Bt^C)^-1+D. This dynamically adjusts the energy parameter based on pulse width to maintain stable resistance characteristics while enabling data writing functionality.

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The patent introduces dynamic control by making the maximum allowable energy dependent on the pulse width parameter. The energy limit is not fixed but varies dynamically according to the relationship defined by constants A, B, C, and D, allowing optimization of both writing capability and stability.

Inventive Principle:

Principle #15Dynamics

2Productivity

If large writing current is passed to the conducting portion, then data writing efficiency improves, but electrical breakdown of the device portion occurs

Engineering Contradiction:

Improvedata writing efficiencyVSAvoiddevice portion integrity

Core Design Contradiction:

ProductivityVSStrength

Solution Approach 1:

The patent implements beforehand cushioning by pre-establishing the energy-pulse width relationship constraint before actual data writing operations. This preventive measure ensures that the applied energy never exceeds the threshold that would cause electrical breakdown, while still allowing efficient writing within safe limits.

Inventive Principle:

Principle #11Beforehand cushioning (Prior cushioning)

3Measurement precision

If energy is applied to screen devices, then device inspection accuracy improves, but resistance changes make screening difficult

Engineering Contradiction:

Improvedevice inspection accuracyVSAvoidresistance stability

Core Design Contradiction:

Measurement precisionVSReliability

Solution Approach 1:

The patent applies parameter changes by using the established energy-pulse width relationship to control the inspection process. By adjusting energy parameters according to pulse width, the method achieves accurate device screening while maintaining stable resistance characteristics for reliable measurement.

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

This approach enables stable data writing and effective screening of devices by maintaining the insulating properties of the non-magnetic layer, preventing abrupt resistance decreases and ensuring accurate resistance changes for magnetoresistance measurements.

Implementation Method 1

a device portion stacked on one surface of the conducting portion and including a non-magnetic layer and a ferromagnetic layer

Methodology Applied

Scientific EffectElectrical insulation: Conduction (electrical)

Implementation Method 2

A SOT is induced by a pure spin current generated by a spin-orbit interaction or by the Rashba effect at the interface between different materials

Methodology Applied

Scientific EffectSpin-orbit interaction:

Implementation Method 3

A SOT is induced by a pure spin current generated by a spin-orbit interaction or by the Rashba effect at the interface between different materials

Methodology Applied

Scientific EffectRashba effect:

Implementation Method 4

a giant magneto-resistance (GMR) device formed of a multi-layer film including a ferromagnetic layer and a non-magnetic layer

Methodology Applied

Scientific EffectGiant magneto-resistance (GMR): Magnetoresistance

Implementation Method 5

a tunneling magneto-resistance (TMR) device in which an insulating layer (a tunneling barrier layer and a barrier layer) is used for a non-magnetic layer

Methodology Applied

Scientific EffectTunneling magneto-resistance (TMR): Magnetoresistance

Implementation Method 6

In a domain wall motion-type magnetic recording device, a domain wall in a magnetic recording layer is moved whereby a resistance changes in a stepwise manner

Methodology Applied

Scientific EffectDomain wall motion:

Data Source

PatentUS10490249B2Data writing method, inspection method, spin device manufacturing method, and magnetoresistance effect element

Publication Date: 2019.11.26 TDK CORP

AI summary

A data writing method is configured such that a spin device includes a conducting portion extending in a first direction and a device portion stacked on one surface of the conducting portion and including a non-magnetic layer and a ferromagnetic layer, wherein an energy equal to or smaller than an energy represented by a predetermined relational expression (1) is applied in the first direction of the conducting portion when the pulse width of an applied pulse is t.