Tellurium Alkoxide Precursor Synthesis for Phase Change Memory

Solution Overview

Problem

The challenge in fabricating smaller and denser phase change memory integrated circuitry is to maintain reliability while scaling down the size of phase change materials, such as GeTe and GeSbTe, which require efficient methods for depositing and forming phase change materials with precise control over composition and thickness.

Innovation Solution

The method involves depositing a phase change material comprising germanium and tellurium using chemical vapor deposition (CVD) and atomic layer deposition (ALD) techniques, where germanium and tellurium precursors are used to form a self-limiting compound with controlled thickness and composition, enabling the formation of reliable phase change memory circuitry.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If phase change materials are scaled down to increase circuitry density, then device density is improved, but reliability deteriorates

Engineering Contradiction:

Core Design Contradiction:

ProductivityVSReliability

Solution Approach 1:

The patent employs atomic layer deposition (ALD) to precisely control the thickness and composition parameters of phase change material layers. By adjusting deposition parameters such as precursor flow rates, temperature, and cycle numbers, the invention achieves reliable phase change material films at scaled dimensions, resolving the contradiction between density improvement and reliability maintenance

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The patent implements in-situ monitoring and control during the deposition process to maintain precise thickness and composition control. Feedback mechanisms monitor deposition rates and material properties in real-time, allowing dynamic adjustment of process parameters to ensure reliable phase change material formation at scaled dimensions

Inventive Principle:

Principle #23Feedback

2Productivity

If chemical vapor deposition is used to deposit phase change materials, then deposition efficiency is improved, but composition control precision deteriorates

Engineering Contradiction:

Core Design Contradiction:

ProductivityVSManufacturing precision

Solution Approach 1:

The patent segments the deposition process into multiple atomic layer deposition cycles, where each cycle deposits a controlled monolayer or sub-monolayer of material. This segmentation allows precise control over composition by controlling the number of cycles and the sequence of precursor exposures, while maintaining high overall deposition efficiency through automated process sequencing

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The patent employs periodic alternating exposure to different precursors (e.g., germanium precursor followed by tellurium precursor) in a cyclic manner. This periodic action enables precise compositional control by controlling the ratio and sequence of precursor exposures, while maintaining high deposition efficiency through continuous cyclic operation

Inventive Principle:

Principle #19Periodic action

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 allows for the reliable formation of phase change memory circuitry with precise control over the phase change material's composition and thickness, enhancing the reliability and scalability of phase change memory devices.

Implementation Method 1

Chemical vapor deposition (CVD) is one method by which such phase change materials may be deposited over a substrate

Methodology Applied

Scientific EffectChemical vapor deposition: Chemical Vapour Deposition

Implementation Method 2

depositing a phase change material comprising germanium and tellurium using chemical vapor deposition (CVD) and atomic layer deposition (ALD) techniques

Methodology Applied

Scientific EffectAtomic layer deposition:

Data Source

PatentUS8558032B2Methods of forming a tellurium alkoxide and methods of forming a mixed halide-alkoxide of tellurium

Publication Date: 2013.10.15

AI summary

A method of forming a tellurium alkoxide includes providing a tellurium halide and a non-tellurium alkoxide in a liquid organic solvent. The liquid organic solvent has less moles of alcohol, if any, than moles of tellurium halide in the liquid organic solvent. The tellurium halide and the non-tellurium alkoxide within the liquid organic solvent are reacted to form a reaction product halide and a tellurium alkoxide. The liquid organic solvent is removed from the reaction product halide and the tellurium alkoxide to leave a liquid and/or solid mixture comprising the reaction product halide and the tellurium alkoxide. The mixture is heated effective to gasify the tellurium alkoxide from the reaction product halide. Other implementations are disclosed, including methods of forming a mixed halide-alkoxide of tellurium.