Self-Aligned Magnetic Memory Etching via Spacer Masks

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Solution Overview

Problem

Current magnetic memory devices face challenges in achieving quick reading/writing features and low operating voltage while maintaining high processing speed and nonvolatility, which are essential for next-generation memory devices.

Innovation Solution

A method of forming a magnetic memory device involves sequentially forming magnetic conductors, tunnel barrier layers, and spacer layers on a substrate, followed by primary and secondary etching processes using mask patterns and spacers to create self-aligned conductive patterns, minimizing exposure of precious metals and preventing shorting phenomena.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a magnetic tunnel junction pattern is formed with two magnetic bodies and an insulating layer, then the device can achieve high-speed operations and nonvolatility, but the resistance value difference between parallel and antiparallel magnetization directions is insufficient for reliable data writing and reading

Engineering Contradiction:

Improvedata writing and reading reliabilityVSAvoidmagnetization direction control precision

Core Design Contradiction:

ReliabilityVSManufacturing precision

Solution Approach 1:

The patent segments the magnetic tunnel junction structure into distinct layers with specific magnetization directions. The first magnetic conductor layer is configured with in-plane magnetization while the second magnetic conductor layer has perpendicular magnetization, creating well-defined magnetic states that improve reliability of data operations

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The patent applies different magnetic properties to different regions of the magnetic tunnel junction. By creating localized magnetic anisotropy through specific layer compositions and structures, the patent achieves distinct parallel and antiparallel magnetization states with sufficient resistance difference for reliable data reading

Inventive Principle:

Principle #3Local quality

2Ease of manufacture

If precious metal layers are exposed during etching processes, then the manufacturing process becomes simpler, but shorting phenomena occur and device reliability decreases

Engineering Contradiction:

Improveetching process simplicityVSAvoiddevice reliability

Core Design Contradiction:

Ease of manufactureVSReliability

Solution Approach 1:

The patent forms a protective mask pattern and spacer structure before performing the etching process. This preliminary protective action prevents precious metal layers from being exposed during etching, thereby avoiding shorting phenomena while maintaining manufacturing feasibility

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The patent introduces a spacer layer as an intermediary protective element between the etching process and the precious metal layers. This spacer acts as a mediator that prevents direct contact between the etchant and precious metals, eliminating shorting risks while allowing the etching process to proceed

Inventive Principle:

Principle #24Intermediary (Mediator)

3Use of energy by moving object

If the resistance value of the magnetic tunnel junction is reduced for low operating voltage, then power consumption decreases, but the signal strength for data reading becomes insufficient

Engineering Contradiction:

Improveoperating voltageVSAvoidresistance detection precision

Core Design Contradiction:

Use of energy by moving objectVSMeasurement precision

Solution Approach 1:

The patent optimizes the resistance value parameters of the magnetic tunnel junction by adjusting layer thicknesses, compositions, and magnetic anisotropy. This allows achieving a balanced resistance value that enables low operating voltage while maintaining sufficient signal strength for reliable data reading through precise parameter control

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 enhances the formation of magnetic memory devices by ensuring precise etching and minimizing defects, thereby improving the magnetic memory cell's performance in terms of data writing and reading, and maintaining low operating voltage.

Implementation Method 1

performing a primary etching of the second magnetic conductor by using the mask pattern as an etching mask

Methodology Applied

Scientific EffectEtching:

Data Source

PatentUS8119425B2Method of forming magnetic memory device

Publication Date: 2012.02.21 SAMSUNG ELECTRONICS CO LTD

AI summary

There are provided a magnetic memory device and a method of forming the magnetic memory device. The method of forming the magnetic memory device includes sequentially forming a first magnetic conductor, a tunnel barrier layer, and a second magnetic conductor on a substrate, forming a mask pattern on the second magnetic conductor, performing a primary etching of the second magnetic conductor by using the mask pattern as an etching mask, forming at least one spacer on sidewalls of the second magnetic conductor formed by the primary etching, and performing a secondary etching of the first magnetic conductor by using the mask pattern and the at least one spacers as an etching mask.