Magnetic Memory Reference Cell Perpendicular Magnetization

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Solution Overview

Problem

Magnetic memory devices face challenges in achieving high integration and low power consumption while maintaining fast write/read operations and non-volatile characteristics, necessitating innovative solutions to enhance their performance and efficiency.

Innovation Solution

The introduction of a magnetic memory device structure that includes a reference cell with a specific magnetic layer configuration, such as a reference magnetic layer with a magnetization direction perpendicular to the free layer, allowing for resistance-based data reading without pre-writing, and utilizing non-magnetic metal oxide layers to control magnetization directions and resistance values.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of time

If a magnetic memory device uses conventional reading methods, then data can be read, but pre-writing processes are required which increase operation time and power consumption

Engineering Contradiction:

Improvereading operation timeVSAvoidpower consumption

Core Design Contradiction:

Loss of timeVSUse of energy by moving object

Solution Approach 1:

The reference cell is pre-configured with a reference magnetic layer having perpendicular magnetization to establish a known resistance state before reading operations. This preliminary setup eliminates the need for pre-writing processes during reading, directly reducing operation time and power consumption while maintaining accurate data reading capability.

Inventive Principle:

Principle #10Preliminary action

2Productivity

If magnetic memory devices increase integration density, then more storage capacity is achieved, but maintaining fast write/read operations becomes more difficult

Engineering Contradiction:

Improvewrite/read operation speedVSAvoiddevice structure complexity

Core Design Contradiction:

ProductivityVSDevice complexity

Solution Approach 1:

The magnetic memory device is segmented into functional units: memory cells for data storage and reference cells for reading reference. This segmentation allows each component to be optimized independently, maintaining fast read operations through the reference cell mechanism while supporting high integration density through compact memory cell structures.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The reference cell acts as an intermediary component that provides a stable resistance reference for reading operations. By introducing this intermediary element with perpendicular magnetization, the device achieves accurate reading without requiring complex pre-writing sequences, thus maintaining speed despite increased integration density.

Inventive Principle:

Principle #24Intermediary (Mediator)

3Use of energy by stationary object

If magnetic memory devices reduce operation voltage, then power consumption decreases, but maintaining non-volatile characteristics and fast operations becomes more challenging

Engineering Contradiction:

Improveoperation voltageVSAvoidnon-volatile characteristics

Core Design Contradiction:

Use of energy by stationary objectVSReliability

Solution Approach 1:

The reference magnetic layer is designed with perpendicular magnetization orientation, which changes the resistance state parameters compared to conventional parallel magnetization. This parameter change enables the reference cell to provide stable resistance references at lower operation voltages while maintaining non-volatile characteristics, as the perpendicular magnetization configuration provides enhanced stability against thermal fluctuations.

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 configuration enables efficient data reading and writing in magnetic memory devices by providing a reference resistance value, reducing power consumption, and eliminating the need for pre-writing processes, thus enhancing integration and performance.

Implementation Method 1

The resistance value of a magnetic tunnel junction may vary depending on the magnetization direction of the two magnetic materials. For example, the magnetic tunnel junction may have a relatively high resistance value in a case where the magnetization direction of the two magnetic materials are anti-parallel to each other, and have a relatively low resistance value in a case where the magnetization direction of the two magnetic materials are parallel.

Methodology Applied

Scientific EffectMagnetoresistance: Magnetoresistance

Implementation Method 2

The reference magnetic layer has a magnetization direction substantially perpendicular to that of the free layer. The magnetization direction of the reference magnetic layer may be fixed in a direction substantially perpendicular to a magnetization easy-axis of the free layer when a read current is applied to the reference cell.

Methodology Applied

Scientific EffectMagnetoresistance: Magnetoresistance

Data Source

PatentUS8934288B2Magnetic memory devices

Publication Date: 2015.01.13 SAMSUNG ELECTRONICS CO LTD

AI summary

Magnetic memory devices are provided, the devices include at least memory cell and a reference cell on a substrate. The memory cells include a first base magnetic layer, a free layer, and a first tunnel barrier layer between the first base magnetic layer and free layer. The reference memory cell includes a second base magnetic layer, a reference magnetic layer, and a second tunnel barrier layer between the second base magnetic layer and reference magnetic layer. The reference magnetic layer has a magnetic direction substantially perpendicular to that of the free layer.