MTJ Segmentation via Insulation Barriers for MRAM Reliability

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Solution Overview

Problem

As magnetic random access memory (MRAM) devices become highly integrated, the distance between neighboring memory cells or magnetic tunnel junction (MTJ) structures decreases, leading to a degradation in the reliability of the MTJ structure due to etching damage and incomplete separation during the etching process.

Innovation Solution

The magnetic memory device incorporates insulation material patterns, such as silicon oxide, silicon nitride, or silicon oxynitride, to segment and separate magnetic material patterns within the MTJ structure, eliminating the need for additional etching processes and reducing etching damage by forming a bulk-type layer stack with magnetic material patterns distributed in the first and second magnetic layers.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If the distance between neighboring MTJ structures is decreased for high integration, then the density of memory cells is improved, but the reliability of the MTJ structure degrades due to etching damage and incomplete separation

Engineering Contradiction:

Improvememory cell densityVSAvoidMTJ structure reliability

Core Design Contradiction:

ProductivityVSReliability

Solution Approach 1:

The magnetic layer is divided into multiple magnetic material patterns separated by insulation material patterns. These insulation patterns act as physical barriers that prevent etching damage from propagating between adjacent MTJ structures, thereby maintaining reliability even when structures are closely spaced for high integration density

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

Insulation material patterns are introduced as intermediary elements between adjacent magnetic material patterns. These intermediary insulation layers prevent direct interaction and potential short-circuits between neighboring MTJ structures, enabling reliable operation at reduced pitch distances

Inventive Principle:

Principle #24Intermediary (Mediator)

2Manufacturing precision

If additional etching processes are used to separate magnetic material patterns, then the separation precision is improved, but the manufacturing complexity and etching damage increase

Engineering Contradiction:

Improvemagnetic material pattern separation precisionVSAvoidetching process complexity

Core Design Contradiction:

Manufacturing precisionVSDevice complexity

Solution Approach 1:

Insulation material patterns are formed beforehand between magnetic material patterns during the deposition process, creating pre-defined separation regions. This preliminary action eliminates the need for subsequent etching steps to create separation, reducing manufacturing complexity while maintaining precise pattern separation

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The mechanical etching process is replaced by a deposition-based approach where insulation material patterns are grown or deposited between magnetic material patterns. This substitution eliminates the harmful mechanical removal of material while achieving the same separation objective with greater precision and less damage

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Data Source

PatentUS9437654B2Magnetic memory devices

Publication Date: 2016.09.06 SAMSUNG ELECTRONICS CO LTD

AI summary

Magnetic memory devices may include a substrate, a circuit device on the substrate, a plurality of lower electrodes electrically connected to the circuit device, a magnetic tunnel junction (MTJ) structure commonly provided on the plurality of the lower electrodes, and a plurality of upper electrodes on the MTJ structure. The MTJ structure may include a plurality of magnetic material patterns and a plurality of insulation material patterns separating the magnetic material patterns from each other.