Yttria Ceramic Flow Path for Plasma Erosion and Crack Resistance
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Solution Overview
Problem
Conventional ceramic sintered bodies used in plasma processing apparatuses face challenges in corrosion resistance and durability due to exposure to plasma atmospheres, particularly in film forming and etching processes, where components like yttria and sintering aids do not adequately prevent erosion and cracking.
Innovation Solution
A ceramic sintered body with yttrium oxide as the main component, containing yttrium silicate and yttrium aluminum oxide, is developed with a specific X-ray diffraction peak intensity ratio that enhances corrosion resistance and reduces particle generation from grain boundaries, and is used to create a member with a cylindrical structure where the inner surface has a higher concentration of these materials for improved plasma exposure resistance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional ceramic sintered bodies containing yttria and sintering aids are used in plasma processing apparatuses, then the apparatus can perform film forming and etching processes, but the ceramic components suffer from erosion and cracking due to plasma exposure, reducing corrosion resistance and durability
Solution Approach 1:
The invention changes the chemical composition parameters by incorporating specific amounts of yttrium silicate (5-50 mass%) and yttrium aluminum oxide (5-50 mass%) in addition to yttria, and controls the sintering temperature (1600-1800°C) and time (2-4 hours) to achieve optimal corrosion resistance against plasma erosion
Solution Approach 2:
The invention creates a composite ceramic material combining multiple oxide components (yttria, yttrium silicate, yttrium aluminum oxide) with complementary properties, where each component contributes to different aspects of plasma resistance, overall structural integrity, and thermal stability
2Manufacturing precision
If conventional ceramic sintered bodies are used in plasma processing apparatuses, then the apparatus can operate, but particles are generated from grain boundaries during plasma exposure, affecting manufacturing precision
Solution Approach 1:
The invention changes the microstructural parameters by controlling grain size (10-50 μm) through specific sintering conditions and composition, which suppresses particle generation from grain boundaries during plasma processing while maintaining manufacturing precision
3Reliability
If ceramic sintered bodies with high yttria content are used to improve corrosion resistance, then plasma exposure resistance improves, but thermal expansion coefficient mismatch causes cracking
Solution Approach 1:
The invention adjusts the thermal expansion coefficient parameter by incorporating yttrium silicate and yttrium aluminum oxide with different thermal expansion characteristics, achieving a balanced coefficient that matches supporting structures while maintaining plasma resistance through optimized composition ratios
Solution Approach 2:
The invention uses a composite material system where yttrium silicate and yttrium aluminum oxide act as buffer phases that accommodate thermal expansion differences, preventing cracks while preserving the plasma corrosion resistance provided by the yttria-based matrix
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 ceramic sintered body with yttrium silicate and yttrium aluminum oxide provides enhanced corrosion resistance and reduced particle generation, allowing for longer apparatus lifespan and improved plasma stability by applying compressive stress to amorphous and crystal particles, while maintaining appropriate thermal expansion coefficients to prevent cracking.
Implementation Method 1
applying compressive stress to amorphous and crystal particles
Implementation Method 2
a ratio (I1/I0) of a maximum peak intensity I1 of yttrium silicate having a diffraction angle 2θ of 30° to 32° with respect to a maximum intensity I0 of yttrium oxide having a diffraction angle 2θ of 28° to 30°, which is obtained by an X-ray diffraction method
Implementation Method 3
maintaining appropriate thermal expansion coefficients to prevent cracking
Data Source
AI summary
The ceramic sintered body of the present disclosure has yttrium oxide as a main component and contains yttrium silicate, and a ratio (I1/I0) of a maximum peak intensity I1 of yttrium silicate having a diffraction angle 2θ of 30° to 32° with respect to a maximum intensity Io of yttrium oxide having a diffraction angle 2θ of 28° to 30°, which is obtained by an X-ray diffraction method, is 0.03 or more and 0.12 or less. The member for the plasma processing apparatus is made of the ceramic sintered body, its inside is a cylindrical body which serves as a flow path for a plasma generating gas, and an inner peripheral surface of the cylindrical body contains a larger amount of yttrium silicate than an outer peripheral surface thereof.