Amorphous Carbon Resistance Memory with Impurity Gradient

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Solution Overview

Problem

Resistance change memory devices face challenges in reliably controlling the formation and restoration of conductive filaments due to variations in the sp2/sp3 bond ratio in amorphous carbon structures, affecting their resistance states and storage capabilities.

Innovation Solution

Incorporating an impurity element with a concentration gradient in the amorphous carbon structure between electrode layers, allowing for controlled generation and disconnection of conductive filaments through applied voltages, thereby stabilizing resistance states for data storage.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If an amorphous carbon structure is used as the resistance change material layer, then the device can achieve non-volatile memory functionality through conductive filament formation, but the resistance states become difficult to control reliably due to variations in the sp2/sp3 bond ratio

Engineering Contradiction:

Improvereliability of forming, set, and reset operationsVSAvoidcontrol over conductive filament formation and restoration

Core Design Contradiction:

ReliabilityVSEase of operation

Solution Approach 1:

The patent introduces impurity elements (such as oxygen, nitrogen, or hydrogen) at specific locations within the amorphous carbon structure to create localized regions with modified bonding characteristics. This local modification allows control over conductive filament formation without changing the entire material structure, thereby improving reliability while maintaining ease of operation.

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The patent modifies the sp2/sp3 bond ratio by introducing impurity elements, which changes the electrical and structural parameters of the amorphous carbon layer. This parameter change enables more predictable and reliable control over resistance states during forming, set, and reset operations, directly addressing the reliability issue.

Inventive Principle:

Principle #35Parameter changes

2Adaptability or versatility

If the sp2/sp3 bond ratio in the amorphous carbon structure is varied to control resistance states, then storage capabilities can be adjusted, but the variability leads to unreliable control of conductive filament formation

Engineering Contradiction:

Improveadjustability of storage capabilitiesVSAvoidreliability of conductive filament control

Core Design Contradiction:

Adaptability or versatilityVSReliability

Solution Approach 1:

Instead of uniformly varying the sp2/sp3 bond ratio throughout the entire amorphous carbon layer, the patent introduces impurity elements at specific locations to create localized modifications. This approach maintains overall structural consistency while enabling controlled resistance state adjustments, thereby preserving reliability while achieving adaptability in storage capabilities.

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The impurity elements act as intermediary substances that mediate between the carbon atoms in the amorphous structure. These intermediaries modify the bonding characteristics locally, allowing for controlled adjustment of storage capabilities without directly altering the entire carbon structure, thus maintaining reliability while achieving versatility.

Inventive Principle:

Principle #24Intermediary (Mediator)

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 concentration gradient of impurity elements in the amorphous carbon structure enables predictable and reliable control over the formation and restoration of conductive filaments, enhancing the reliability of forming, set, and reset operations in resistance change memory devices.

Implementation Method 1

resistance can be variably changed by applying a voltage across a variable resistance material layer to generate or remove a conductive filament or an insulating interface layer in the variable resistance material layer

Methodology Applied

Scientific EffectConductive filament formation:

Implementation Method 2

The resistance change material layer includes impurity elements adhering to the amorphous carbon structure, and the impurity element has a concentration gradient along a thickness direction of the resistance change material layer

Methodology Applied

Scientific EffectImpurity element concentration gradient:

Implementation Method 3

a resistive memory means a non-volatile memory in which an internal resistance undergoes variable change in response to an externally applied voltage or current, and the change in internal resistance is recorded in a nonvolatile manner

Methodology Applied

Scientific EffectResistive switching:

Data Source

PatentUS10720582B2Resistance change memory device having amorphous carbon structure and method of manufacturing the same

Publication Date: 2020.07.21 SK HYNIX INC

AI summary

There is disclosed a resistance change memory device according to an aspect of the present disclosure. The resistance change memory device includes a first electrode layer and a second electrode layer that are disposed to be spaced apart from each other, and a resistance change material layer disposed between the first and second electrode layers and including an amorphous carbon structure. The resistance change material layer includes an impurity element adhering to the amorphous carbon structure, and the impurity element has a concentration gradient along a thickness direction of the resistance change material layer.