Phase Change Memory Electrodes Using Metal Ceramic Composite Layers

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Solution Overview

Problem

Phase change memory (PCM) structures face challenges in achieving high-density memory with minimal resistivity between bitlines and vias, and require improved thermal efficiency and material stability to optimize operational efficiency.

Innovation Solution

Incorporating a metal ceramic composite material layer with upper and lower barrier layers in PCM cells, where the electrodes include a metal ceramic composite material layer between these barrier layers, helps reduce programming current and enhance thermal efficiency and material stability, thereby minimizing resistivity between bitlines and vias.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If conventional electrode structures are used in PCM cells, then device complexity is reduced, but interface resistance between bitlines and vias increases

Engineering Contradiction:

Improveinterface resistanceVSAvoidelectrode structure

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The patent applies composite materials by using a metal ceramic composite material layer (e.g., tungsten silicon nitride, tantalum silicon nitride, or molybdenum silicon nitride) in the electrode structure. This composite layer is positioned between barrier layers and provides both low resistivity for electrical connection and thermal management properties, resolving the contradiction between reducing interface resistance and maintaining device complexity at acceptable levels.

Inventive Principle:

Principle #40Composite materials

2Reliability

If standard material layers are used in PCM cells, then manufacturing process is simplified, but thermal efficiency and material stability deteriorate

Engineering Contradiction:

Improvematerial stabilityVSAvoidmanufacturing process

Core Design Contradiction:

ReliabilityVSEase of manufacture

Solution Approach 1:

The patent employs metal ceramic composite material layers (such as tungsten silicon nitride, tantalum silicon nitride, or molybdenum silicon nitride) that provide enhanced thermal efficiency and material stability. These composite materials enable better thermal confinement during phase change operations and improved interface stability, while the manufacturing process remains compatible with existing semiconductor fabrication techniques through sequential deposition methods.

Inventive Principle:

Principle #40Composite materials

Solution Approach 2:

The patent applies local quality by positioning specific material layers with distinct properties at different locations within the electrode structure. The metal ceramic composite material layer is placed between barrier layers to provide localized thermal and electrical properties where needed, while other regions maintain standard materials for compatibility and ease of manufacture.

Inventive Principle:

Principle #3Local quality

3Productivity

If PCM structures without metal ceramic composite layers are used, then device complexity is lower, but programming current and resistivity are suboptimal

Engineering Contradiction:

Improveprogramming currentVSAvoidelectrode configuration

Core Design Contradiction:

ProductivityVSDevice complexity

Solution Approach 1:

The patent uses metal ceramic composite material layers (e.g., tungsten silicon nitride, tantalum silicon nitride, or molybdenum silicon nitride) in the electrode structure to reduce programming current and minimize resistivity between bitlines and vias. The composite material provides optimized electrical and thermal properties that enable efficient programming operations while maintaining a manageable device structure through systematic layer integration.

Inventive Principle:

Principle #40Composite materials

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 configuration results in PCM cells with reduced interface resistance between bitlines and vias, improved thermal stability, and enhanced material stability, leading to more efficient and reliable PCM structures.

Implementation Method 1

the metal ceramic composite material layer, and a via having a substantially parallel orientation to the array of PCM cells, a dielectric material separating the via from the array of PCM cells and separating individual PCM cells

Methodology Applied

Scientific EffectThermal conduction: Conduction (thermal)

Implementation Method 2

Different physical states of the phase change material have different levels of electrical resistance. For example, one state, such as an amorphous state, can have a high electrical resistance, while another state, such as a crystalline state, can have a low electrical resistance.

Methodology Applied

Scientific EffectPhase change: Phase Change

Data Source

PatentUS10892406B2Phase change memory structures and devices

Publication Date: 2021.01.12 INTEL CORP

AI summary

A phase change memory (PCM) cell can include a PCM layer. A first electrode and a second electrode disposed on opposite sides of the PCM layer. The first electrode, the second electrode, or both includes a metal ceramic composite material layer disposed between an upper barrier layer and a lower barrier layer and wherein the metal ceramic composite material layer provides a corresponding electrode with an electrical resistivity of from 10 mOhm-cm to 1000 mOhm-cm.