Segmented MRAM Free Layer for Lower Write Power

Solution Overview

Problem

As MRAM devices scale down, the ability to supply write current and voltage decreases, leading to increased power consumption and exacerbated tailing bits due to multiple domains in the free magnetic layer, which hinders storage capacity and system flexibility.

Innovation Solution

A segregated structure for the free magnetic layer with multiple magnetic material pieces separated by a non-magnetic segregation layer replaces the continuous single layer, reducing write current, voltage, and power requirements while maintaining or improving storage capacity.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Quantity of substance

If the free magnetic layer is scaled down to increase storage capacity, then storage density is improved, but write current and voltage requirements increase leading to higher power consumption

Engineering Contradiction:

Improvestorage capacityVSAvoidpower consumption

Core Design Contradiction:

Quantity of substanceVSUse of energy by moving object

Solution Approach 1:

The free magnetic layer is divided into multiple magnetic domains separated by non-magnetic material pieces. This segmentation allows each domain to be switched independently with lower current, reducing the overall power consumption while maintaining high storage capacity through increased domain density.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

Non-magnetic material pieces are strategically placed at specific locations within the free magnetic layer to create localized magnetic domains. This local modification enables precise control of magnetic switching characteristics, reducing write current requirements in specific regions while maintaining overall storage capacity.

Inventive Principle:

Principle #3Local quality

2Quantity of substance

If the free magnetic layer is scaled down to increase storage capacity, then storage density is improved, but tailing bits increase due to multiple domains

Engineering Contradiction:

Improvestorage capacityVSAvoidtailing bits

Core Design Contradiction:

Quantity of substanceVSReliability

Solution Approach 1:

The free magnetic layer is divided into multiple magnetic domains separated by non-magnetic material pieces. This segmentation allows each domain to be switched independently with lower current, reducing the overall power consumption while maintaining high storage capacity through increased domain density.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

Non-magnetic material pieces are strategically placed at specific locations within the free magnetic layer to create localized magnetic domains. This local modification enables precise control of magnetic switching characteristics, reducing write current requirements in specific regions while maintaining overall storage capacity.

Inventive Principle:

Principle #3Local quality

3Quantity of substance

If the free magnetic layer is scaled down to increase storage capacity, then storage density is improved, but device complexity increases

Engineering Contradiction:

Improvestorage capacityVSAvoiddomain structure

Core Design Contradiction:

Quantity of substanceVSDevice complexity

Solution Approach 1:

The free magnetic layer is divided into multiple magnetic domains separated by non-magnetic material pieces. This segmentation allows each domain to be switched independently with lower current, reducing the overall power consumption while maintaining high storage capacity through increased domain density.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

Non-magnetic material pieces are strategically placed at specific locations within the free magnetic layer to create localized magnetic domains. This local modification enables precise control of magnetic switching characteristics, reducing write current requirements in specific regions while maintaining overall storage capacity.

Inventive Principle:

Principle #3Local quality

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 segregated free magnetic layer structure decreases write current, voltage, and power while maintaining storage capacity, reducing the impact of domain scaling on MRAM performance and increasing system flexibility.

Implementation Method 1

An MRAM cell is formed by a magnetic tunneling junction (MTJ) comprising two ferromagnetic layers which are separated by a thin insulating barrier, and operates by tunneling of electrons between the two ferromagnetic layers through the insulating barrier.

Methodology Applied

Scientific EffectElectron tunneling:

Data Source

PatentUS12075631B2Magnetic random access memory and manufacturing method thereof

Publication Date: 2024.08.27 TAIWAN SEMICONDUCTOR MANUFACTURING CO LTD

AI summary

A semiconductor device includes a magnetic random access memory (MRAM) cell. The MRAM cell includes a first magnetic layer disposed over a substrate, a first non-magnetic material layer made of a non-magnetic material and disposed over the first magnetic layer, a second magnetic layer disposed over the first non-magnetic material layer, and a second non-magnetic material layer disposed over the second magnetic layer. The second magnetic layer includes a plurality of magnetic material pieces separated from each other.