Phase Change Memory Current Restrictive Element Resistive Gradient

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Solution Overview

Problem

Phase change memory devices face challenges with high power consumption and heat dissipation, which limit their design and viability due to the substantial energy dissipated by resistive heater elements and the detrimental heat generated.

Innovation Solution

A current restrictive element with multiple film patterns is interposed between the electrically conductive element and the phase change material, featuring a resistive gradient and varying resistivity to focus heat towards the phase change material, minimizing overall heat dissipation and energy consumption.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Temperature

If a resistive heater element is used to heat the phase change material, then the phase change can be controlled, but high power consumption and heat dissipation occur

Engineering Contradiction:

Improvetemperature control of phase change materialVSAvoidpower consumption of heater element

Core Design Contradiction:

TemperatureVSUse of energy by moving object

Solution Approach 1:

The heater element is designed with a resistive gradient where the resistance per unit length varies along its length. The resistance is highest at the distal end (closest to phase change material) and lowest at the proximal end (closest to current source). This creates localized heating concentrated at the distal end, improving heating efficiency and reducing overall power consumption while maintaining effective temperature control of the phase change material.

Inventive Principle:

Principle #3Local quality

2Temperature

If a resistive heater element is used to heat the phase change material, then the phase change can be controlled, but detrimental heat is generated

Engineering Contradiction:

Improvetemperature control of phase change materialVSAvoidheat dissipation from heater element

Core Design Contradiction:

TemperatureVSObject-generated harmful factors

Solution Approach 1:

The resistive gradient concentrates the heat generation at the distal end of the heater element where the resistance is highest, directly at the interface with the phase change material. This localized heating minimizes heat dissipation to surrounding areas and reduces detrimental thermal effects while maintaining effective temperature control.

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The high resistance at the distal end, which would normally cause excessive heat dissipation, is converted into a beneficial concentration of heating power exactly where needed. The resistive gradient transforms what would be a harmful heat dissipation problem into a useful localized heating mechanism that improves overall system efficiency.

Inventive Principle:

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

3Loss of energy

If multiple film patterns with varying resistivity are used in the current restrictive element, then heat can be focused towards the phase change material, but device complexity increases

Engineering Contradiction:

Improveheat dissipation efficiencyVSAvoidstructure of current restrictive element

Core Design Contradiction:

Loss of energyVSDevice complexity

Solution Approach 1:

The current restrictive element uses a continuous gradient of resistivity rather than discrete layers of different materials. The resistance per unit length varies smoothly along the length of the element, creating a gradual transition in electrical properties. This approach achieves effective heat focusing while avoiding the complexity of multiple material interfaces and deposition processes required for discrete layered structures.

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 design allows for a high density of memory cells while reducing total energy consumption and heat dissipation, effectively addressing the limitations of existing phase change memory devices by focusing heat efficiently on the phase change material.

Implementation Method 1

The plurality of film patterns overlap with each other. Accordingly, there are multiple film patterns, the multiple film patterns overlap one another, and each of the overlapping film patterns has a first portion and a second portion. Each of the second portions are configured and dimensioned to have a higher resistance than the first portions.

Methodology Applied

Scientific EffectJoule heating: Joule Heating

Data Source

PatentUS7812332B2Phase change memory device and method of forming the same

Publication Date: 2010.10.12 SAMSUNG ELECTRONICS CO LTD

AI summary

A phase change memory device includes a current restrictive element interposed between an electrically conductive element and a phase change material. The current restrictive element includes a plurality of overlapping film patterns, each of which having a respective first portion proximal to the conductive element and a second portion proximal to the phase change material. The second portions are configured and dimensioned to have higher resistance than the first portions.