Yttrium Oxyfluoride Thermal Spray Slurry for Plasma Erosion Resistance

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Solution Overview

Problem

Thermal spraying of slurries results in lower spray efficiency compared to powders, and increasing the amount of thermal spray particles in the slurry decreases fluidity, making it difficult to form a coating, while also requiring more precise management to prevent contamination by particles, especially in semiconductor devices where plasma erosion resistance is crucial.

Innovation Solution

A thermal spray slurry containing a dispersion medium, dispersant, and thermal spray particles comprising a compound with yttrium, oxygen, and a halogen element, such as yttrium oxyfluoride, with a molar ratio of halogen to yttrium greater than 1, and a solids concentration of 10% to 70% by mass, maintaining fluidity and improving plasma erosion resistance.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If the amount of thermal spray particles in the slurry is increased to raise spray efficiency, then coating speed is improved, but the fluidity of the slurry decreases, making it more difficult to form a thermal spray coating

Engineering Contradiction:
Improvespray efficiencyVSAvoidfluidity
Core Design Contradiction:
ProductivityVSEase of operation

Solution Approach 1:

The patent applies parameter changes by optimizing the solids concentration within a specific range (10-70 mass%) and controlling viscosity (300 mPa·s or less). It also changes the chemical composition parameters of thermal spray particles, using compounds with halogen-to-yttrium molar ratios greater than 1, which improves plasma erosion resistance while maintaining slurry processability at higher solids concentrations.

Inventive Principle:
Principle #35Parameter changes

2Reliability

If the solids concentration is increased to improve coating density, then plasma erosion resistance is enhanced, but the viscosity increases, reducing spray efficiency

Engineering Contradiction:
Improveplasma erosion resistanceVSAvoidspray efficiency
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

The patent resolves this contradiction by changing both concentration parameters (optimizing solids content to 10-70 mass%) and chemical composition parameters (using halogen-containing compounds with specific halogen-to-yttrium ratios). This allows achieving superior plasma erosion resistance through chemical composition while maintaining acceptable viscosity and spray efficiency through optimized concentration control.

Inventive Principle:
Principle #35Parameter changes

3Manufacturing precision

If finer particles are used to improve coating precision, then contamination control is enhanced, but the slurry viscosity increases, making it harder to spray

Engineering Contradiction:
Improvecontamination controlVSAvoidsprayability
Core Design Contradiction:
Manufacturing precisionVSEase of operation

Solution Approach 1:

The patent addresses this contradiction by optimizing the particle size distribution within specific ranges and controlling the solids concentration (10-70 mass%). The use of halogen-containing compounds with specific compositions further helps maintain lower viscosity even with finer particles, enabling both contamination control and sprayability.

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

The slurry allows for the formation of a dense thermal spray coating with superior plasma erosion resistance, suitable for semiconductor manufacturing, by enhancing the thermal spray efficiency and reducing particle contamination.

Implementation Method 1

Thermal spray coatings are formed by thermally spraying thermal spray particles onto a substrate

Methodology Applied
Scientific EffectThermal spray: Plasma Spray

Implementation Method 2

yttrium oxide thermal spray coatings are used as protective coatings for the components of semiconductor device manufacturing equipment because yttrium oxide exhibits good plasma erosion resistance

Methodology Applied
Scientific EffectPlasma erosion resistance: Plasma

Data Source

PatentEP3159426B1Thermal spray slurry, thermal spray coating and method for forming thermal spray coating
Publication Date: 2025.09.17 FUJIMI INCORPORATED

AI summary

Provided is a thermal spray slurry capable of satisfactorily forming a thermal spray coating with superior plasma erosion resistance. The invention provides a thermal spray slurry comprising thermal spray particles and a dispersion medium. The thermal spray particles comprise a compound containing yttrium (Y) and a halogen element (X) as constituent elements, and be present in an amount of 10% by mass or more and 70% by mass or less. The viscosity of the thermal spray slurry is 300 mPa·s or less.