MRAM Magnetic Shielding Layer for Interference Mitigation

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Solution Overview

Problem

Magnetoresistive random-access memory (MRAM) devices experience magnetic field induction interference between adjacent magnetic tunnel junctions (MTJs) during data writing and reading, affecting accuracy and efficiency.

Innovation Solution

A semiconductor device with a magnetic tunnel junction unit surrounded by a magnetic shielding material layer, such as a diamagnetic material like aluminium or nickel iron alloy, to reduce or eliminate magnetic field induction interference.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Quantity of substance

If magnetic tunnel junction units are placed adjacent to each other for high-density storage, then storage density is improved, but magnetic field induction interference between adjacent MTJs increases

Engineering Contradiction:

Improvestorage densityVSAvoidmagnetic field induction interference

Core Design Contradiction:

Quantity of substanceVSObject-affected harmful factors

Solution Approach 1:

A magnetic shielding layer made of diamagnetic material (such as aluminum or nickel-iron alloy) is introduced as an intermediary between adjacent magnetic tunnel junction units. This shielding layer selectively blocks magnetic field induction interference while allowing read and write operations to proceed normally, thus enabling high-density storage without sacrificing signal integrity

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The magnetic shielding layer is selectively positioned only in specific regions where interference occurs, rather than uniformly across the entire device. The layer covers the sidewalls and top surfaces of adjacent MTJs but is removed or reduced in areas where read/write operations need to occur, creating localized protection zones that preserve overall device functionality

Inventive Principle:

Principle #3Local quality

2Object-affected harmful factors

If magnetic shielding material layer is added to reduce interference, then magnetic field induction interference is reduced, but device complexity and manufacturing steps increase

Engineering Contradiction:

Improvemagnetic field induction interferenceVSAvoiddevice complexity

Core Design Contradiction:

Object-affected harmful factorsVSDevice complexity

Solution Approach 1:

The magnetic shielding layer is combined with the existing isolation dielectric layer structure. The shielding material is deposited conformally over the isolation dielectric, and both layers are processed together through the same planarization and patterning steps, merging two functions (isolation and shielding) into a single integrated structure

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The magnetic shielding layer utilizes the existing topography created by the isolation dielectric layer and magnetic tunnel junction units. The conformal deposition process automatically conforms to the underlying structure, and the subsequent planarization step self-adjusts the surface, reducing the need for additional alignment and patterning steps

Inventive Principle:

Principle #25Self-service

3Object-affected harmful factors

If magnetic shielding material layer is added to reduce interference, then magnetic field induction interference is reduced, but manufacturing process steps increase

Engineering Contradiction:

Improvemagnetic field induction interferenceVSAvoidmanufacturing process steps

Core Design Contradiction:

Object-affected harmful factorsVSEase of manufacture

Solution Approach 1:

The magnetic shielding layer is deposited early in the manufacturing process, before final electrode patterning and contact formation. This preliminary placement allows the shielding structure to be established once and then used as a reference for subsequent steps, rather than requiring separate addition later in the process

Inventive Principle:

Principle #10Preliminary action

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 magnetic shielding material layer effectively mitigates magnetic field induction interference between adjacent MTJs, enhancing the accuracy and efficiency of data writing and reading in MRAM devices.

Implementation Method 1

depositing a magnetic shielding material layer on the isolation dielectric layer, wherein the magnetic shielding material layer has a first portion that is located above the magnetic tunnel junction unit and a second portion that covers the sidewall of the magnetic tunnel junction unit and the isolation dielectric layer

Methodology Applied

Scientific EffectMagnetic shielding: Magnetic Field

Implementation Method 2

The magnetic shielding material of the magnetic shielding material layer may be a diamagnetic material including but not limited to aluminium and nickel iron alloy

Methodology Applied

Scientific EffectDiamagnetism: Diamagnetism

Data Source

PatentUS9048413B2Semiconductor magnetoresistive random-access memory (MRAM) device and manufacturing method thereof

Publication Date: 2015.06.02 SEMICON MFG INT (SHANGHAI) CORP

AI summary

The present disclosure describes a semiconductor MRAM device and a manufacturing method. The device reduces magnetic field induction “interference” (disturbance) phenomenon between adjacent magnetic tunnel junctions when data is written and read. This semiconductor MRAM device comprises a magnetic tunnel junction unit and a magnetic shielding material layer covering the sidewalls of the magnetic tunnel junction unit. The method for manufacturing a semiconductor device comprises: forming a magnetic tunnel junction unit, depositing an isolation dielectric layer to cover the top and the sidewall of the magnetic tunnel junction unit, and depositing a magnetic shielding material layer on the isolation dielectric layer.