Boron Implantation for MTJ Sidewall Isolation

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

The existing methods for fabricating magnetic memory devices using magnetic tunnel junctions (MTJ) face challenges in removing etching by-products from the sidewalls, which can lead to electrical short circuits and deterioration of magnetic characteristics, limiting the reliability and performance of the devices.

Innovation Solution

A method involving the implantation of boron to form boron oxide on the sidewalls of the MTJ structure, converting conductive etching by-products into non-conductive materials, thereby preventing electrical short circuits and maintaining the integrity of the magnetic and electrical characteristics.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If conventional etching processes are used to form MTJ structures, then the MTJ structure can be fabricated, but etching by-products remain on the sidewall causing electrical short circuits and deterioration of magnetic characteristics

Engineering Contradiction:

ImproveMTJ structure formationVSAvoidelectrical short circuit prevention

Core Design Contradiction:

Manufacturing precisionVSReliability

Solution Approach 1:

The patent converts the harmful etching by-products into beneficial boron oxide materials by implanting boron ions onto the sidewalls where etching by-products accumulate. The boron reacts with oxygen to form boron oxide, which is non-conductive and prevents electrical short circuits while maintaining the magnetic characteristics of the MTJ structure.

Inventive Principle:

Principle #22Blessing in disguise (Convert harm into benefit)

Solution Approach 2:

The patent introduces boron as an intermediary substance that mediates between the harmful etching by-products and the desired clean sidewall. The boron implants onto the sidewall and reacts to form boron oxide, which acts as a protective layer preventing electrical short circuits caused by the etching by-products.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Manufacturing precision

If conventional etching processes are used to form MTJ structures, then the MTJ structure can be fabricated, but etching by-products remain on the sidewall causing deterioration of magnetic characteristics

Engineering Contradiction:

ImproveMTJ structure formationVSAvoidmagnetic characteristics deterioration

Core Design Contradiction:

Manufacturing precisionVSObject-affected harmful factors

Solution Approach 1:

Inventive Principle:

Principle #22Blessing in disguise (Convert harm into benefit)

3Reliability

If additional boron implantation process is added to remove etching by-products, then electrical short circuits are prevented, but the fabrication process complexity increases

Engineering Contradiction:

Improveelectrical short circuit preventionVSAvoidfabrication process complexity

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The patent merges the boron implantation process with the existing fabrication process flow, integrating it as a standard step after MTJ structure formation. By combining the by-product removal function with the fabrication process itself rather than adding a separate complex removal process, the overall device complexity is minimized while achieving reliable electrical isolation.

Inventive Principle:

Principle #5Merging (Combining)

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 effectively suppresses the deterioration of electrical and magnetic characteristics while substantially removing etching by-products, enhancing the reliability and performance of the magnetic memory devices by preventing electrical short circuits.

Implementation Method 1

forming a boron oxide in a sidewall of the MTJ structure by implanting boron

Methodology Applied

Scientific EffectIon implantation: Ion Implantation

Implementation Method 2

forming a boron oxide in a sidewall of the MTJ structure by implanting boron

Methodology Applied

Scientific EffectOxidation: Oxidation

Data Source

PatentUS9985202B2Method of fabricating memory device

Publication Date: 2018.05.29 SAMSUNG ELECTRONICS CO LTD

AI summary

A method of fabricating a memory device, the method including forming a first magnetization layer; forming a tunnel barrier layer on the first magnetization layer; forming a second magnetization layer on the tunnel barrier layer; forming a magnetic tunnel junction (MTJ) structure by patterning the first magnetization layer, the tunnel barrier layer, and the second magnetization layer; and forming a boron oxide in a sidewall of the MTJ structure by implanting boron.