Ion Beam Etching Sidewall Oxidation Magnetic Memory

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Solution Overview

Problem

Magnetic memory devices face challenges in achieving high density and low power consumption, with existing etching processes leading to conductive residues that cause short-circuits and electrical connections between adjacent tunnel junctions, especially at high integration densities.

Innovation Solution

An ion beam etching process using an oxygen-containing reactive source gas, such as O2, O3, NO, NO2, N2O, CO, or CO2, is employed to remove etching by-products and oxidize the sidewalls of magnetic tunnel junction structures, forming a metal oxide layer that prevents short-circuits, while maintaining low incident energy and temperature to minimize damage.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If conventional etching processes are used to form magnetic tunnel junction structures, then the etching process can be completed, but conductive residues remain on sidewalls causing short-circuits between adjacent structures

Engineering Contradiction:

Improveelectrical connection reliabilityVSAvoidconductive residues

Core Design Contradiction:

ReliabilityVSObject-generated harmful factors

Solution Approach 1:

The patent converts the harmful conductive residues into beneficial insulating metal oxide layers by introducing oxygen during the ion beam etching process. The oxygen reacts with the metal residues to form insulating oxides, transforming the short-circuit problem into a protective insulating layer that prevents electrical breakdown between adjacent magnetic tunnel junction structures.

Inventive Principle:

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

Solution Approach 2:

The patent uses oxygen plasma or oxygen-containing gases during the ion beam etching process to accelerate the oxidation of metal residues on the sidewalls. This strong oxidizing environment rapidly converts conductive metal residues into insulating metal oxides, effectively preventing short-circuits while the etching process is ongoing.

Inventive Principle:

Principle #38Strong oxidants (Accelerated oxidation)

2Reliability

If ion beam etching is used to remove residues, then short-circuits are prevented, but additional process steps increase manufacturing complexity

Engineering Contradiction:

Improveelectrical connection reliabilityVSAvoidetching process complexity

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The patent merges the etching process with the residue removal and oxidation process into a single ion beam etching step. By introducing oxygen during the etching process, the patent simultaneously etches the magnetic tunnel junction structures, removes metal residues, and forms insulating oxide layers, eliminating the need for separate cleaning and oxidation steps.

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The ion beam etching process is given multiple functions: it etches the magnetic tunnel junction structures to the required depth, removes conductive metal residues from sidewalls, and forms insulating metal oxide layers. This multi-functional approach simplifies the overall manufacturing process while improving reliability.

Inventive Principle:

Principle #6Universality (Multi-functionality)

3Productivity

If high incident energy is used in ion beam etching, then etching efficiency is improved, but damage to the magnetic tunnel junction structures increases

Engineering Contradiction:

Improveetching efficiencyVSAvoidstructure integrity

Core Design Contradiction:

ProductivityVSManufacturing precision

Solution Approach 1:

The patent optimizes the ion beam parameters by using moderate incident energy levels that balance etching efficiency with structure preservation. The oxygen introduction compensates for slower etching rates by preventing residue formation, while the controlled energy levels minimize damage to the magnetic tunnel junction structures during the etching process.

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 method effectively reduces short-circuits and enhances the reliability of magnetic memory devices by forming a controlled metal oxide layer on the sidewalls, improving the integration density and operational stability of magnetic memory devices.

Implementation Method 1

performing an ion beam etching process using an oxygen-containing reactive source gas to remove etching by-products on sidewalls of the magnetic tunnel junction structures and simultaneously to oxidize the sidewalls of the magnetic tunnel junction structures

Methodology Applied

Scientific EffectOxidation: Oxidation

Implementation Method 2

performing an ion beam etching process using an oxygen-containing reactive source gas to remove etching by-products on sidewalls of the magnetic tunnel junction structures

Methodology Applied

Scientific EffectIon beam etching: Ion Beam

Data Source

PatentUS9246082B2Method of forming magnetic memory devices

Publication Date: 2016.01.26 SAMSUNG ELECTRONICS CO LTD

AI summary

Provided is a method of forming a magnetic memory device. A first magnetic layer, a tunnel barrier, and a second magnetic layer are deposited on a substrate. The second magnetic layer, the tunnel barrier, and the first magnetic layer are etched to form magnetic tunnel junction structures. An ion beam etching process is performed using an oxygen-containing source gas to remove etching by-products on sidewalls of the magnetic tunnel junction structure and to oxidize the sidewalls of the magnetic tunnel junction structures.