Variable Resistance Memory Device Patterning Process

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Solution Overview

Problem

Current non-volatile memory devices face challenges in achieving high performance and low power consumption while maintaining uniform resistance after power interruption, which limits their efficiency and reliability.

Innovation Solution

A method of manufacturing a variable resistance memory device involves forming switching layers, heating layers, and conductive layers in a specific pattern to create memory cells with a series connection of switching elements, intermediate electrodes, heating patterns, and variable resistance patterns, allowing for efficient data storage and reduced patterning processes.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If conventional non-volatile memory devices are used, then data retention without power supply is achieved, but manufacturing complexity and power consumption increase while performance is limited

Engineering Contradiction:

Improvedata retentionVSAvoidmanufacturing complexity

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The memory device is divided into distinct functional layers including switching layers, heating layers, variable resistance layers, and conductive layers. Each layer performs a specific function, allowing for modular manufacturing and simplified process control while maintaining reliable data retention capabilities

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The patent transitions from planar memory structures to vertically stacked three-dimensional structures with multiple layers extending in the thickness direction. This dimensional change increases storage density and improves electrical characteristics while reducing the number of patterning steps required in the manufacturing process

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

2Ease of manufacture

If conventional memory device structures are used, then basic storage function is achieved, but the number of patterning steps increases manufacturing complexity

Engineering Contradiction:

Improvepatterning processVSAvoidnumber of patterning steps

Core Design Contradiction:

Ease of manufactureVSDevice complexity

Solution Approach 1:

Multiple functional layers (switching layers, heating layers, variable resistance layers) are combined in a stacked configuration and processed together through shared patterning steps. This merging of functions into unified structural units reduces the total number of separate patterning operations required during manufacturing

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The heating layers and switching layers are formed with predetermined patterns and positions before the final variable resistance layer formation. This preliminary structuring allows subsequent layers to be aligned and integrated more efficiently, reducing the number of corrective patterning steps needed

Inventive Principle:

Principle #10Preliminary action

3Manufacturing precision

If variable resistance patterns are exposed to etchants during patterning, then patterning completion is achieved, but pattern uniformity and resistance consistency deteriorate

Engineering Contradiction:

Improvepattern uniformityVSAvoidpatterning process efficiency

Core Design Contradiction:

Manufacturing precisionVSProductivity

Solution Approach 1:

A sacrificial mask layer or protective coating is introduced as an intermediary between the etching process and the variable resistance patterns. This intermediary protects the patterns from direct etchant exposure, maintaining their uniformity and resistance characteristics while still allowing the patterning process to proceed

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent utilizes the etching process to selectively remove sacrificial materials or adjust layer interfaces in a way that actually enhances the definition and uniformity of the variable resistance patterns. The potential harmful effect of etchant exposure is converted into a beneficial process that improves pattern quality

Inventive Principle:

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

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 simplifies the manufacturing process, reduces the number of patterning steps, and ensures that variable resistance patterns are not exposed to etchants, thereby enhancing the memory device's performance and reliability by maintaining uniform resistance and efficient data storage.

Implementation Method 1

forming a heating layer on the switching layer, the heating layer extending in a first direction

Methodology Applied

Scientific EffectJoule heating: Joule Heating

Data Source

PatentUS10566386B2Variable resistance memory device and method of manufacturing the same

Publication Date: 2020.02.18 SAMSUNG ELECTRONICS CO LTD

AI summary

A method of manufacturing a variable memory device includes forming a switching layer on a first conductive layer, forming a heating layer on the switching layer, the heating layer extending in a first direction, performing a first patterning process on the first conductive layer, the switching layer, and the heating layer to form a first trench extending in a second direction intersecting the first direction, forming variable resistance patterns on the heating layer, forming a second conductive layer on the variable resistance patterns, and performing a second patterning process on the switching layer, the heating layer, and the second conductive layer to form a second trench extending in the first direction and being between the variable resistance patterns.