Sintered α-SiC Plasma Processing Member With Low-Impurity Durability
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current silicon carbide (SiC) members for plasma processing apparatuses are expensive due to high production costs and limited plasma resistance, especially when using high-purity β-SiC prepared by CVD processes, and α-SiC members contain metal impurities leading to chamber contamination.
Innovation Solution
A silicon carbide member is produced using a sintered body of α-structure silicon carbide with controlled metal impurity levels and an oxide-based sintering aid comprising Al2O3 and Y2O3, processed to achieve high plasma resistance at lower costs, with specific sintering conditions and aids to enhance durability and plasma resistance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If high-purity β-SiC prepared by CVD process is used, then plasma resistance is improved, but production cost increases significantly
Solution Approach 1:
The invention changes the crystal structure parameter from β-SiC to α-SiC and controls impurity parameters (metal impurities ≤70 ppm, Al impurities ≤50 ppm) to achieve high plasma resistance. This parameter transformation allows using a different material system (α-SiC sintered body) that can be produced more cost-effectively while maintaining the required plasma resistance performance
Solution Approach 2:
The invention uses a composite material approach by creating a sintered body from α-SiC powder with controlled impurity levels. The sintered composite structure combines multiple α-SiC particles with interstitial material, achieving both cost-effectiveness and high plasma resistance that cannot be obtained from single-crystal β-SiC alone
2Ease of manufacture
If α-SiC is used, then production cost is reduced, but metal impurities cause chamber contamination
Solution Approach 1:
The invention applies strict parameter control on metal impurities (≤70 ppm) and Al impurities (≤50 ppm) in the α-SiC material. By transforming the impurity level parameters from conventional levels to these controlled levels, the material maintains cost advantages while eliminating chamber contamination issues that would otherwise result from higher impurity content
Solution Approach 2:
The invention uses α-SiC sintered bodies that can be produced at lower cost compared to CVD β-SiC. While individual components may have limited service life, the low production cost allows for economical replacement, and the controlled impurity levels ensure they do not cause chamber contamination during their service period
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 approach results in a cost-effective SiC member with improved plasma resistance and durability, suitable for plasma processing apparatuses, reducing production costs and minimizing metal impurity-related contamination issues.
Implementation Method 1
a silicon carbide member for a plasma processing apparatus, which consists of a sintered body of an α-silicon carbide
Data Source
Figure 1~2
Figure 3
Figure 4
AI summary
The present invention has an object to provide a low-cost, durable silicon carbide member for a plasma processing apparatus. The silicon carbide member for a plasma processing apparatus of the present invention can be obtained by processing a sintered body which is produced with a method in which metal impurity is reduced to more than 20 ppm and 70 ppm or less, and an α-structure silicon carbide power having an average particle diameter of 0.3 to 3 µm and including 50 ppm or less of an Al impurity is mixed with 0.5 to 5 weight parts of a B4C sintering aid, or with a sintering aid comprising Al2O3 and Y2O3 with total amount of 3 to 15 weight parts, and then a mixture of the α-structure silicon carbide power with the sintering aid is sintered in an argon atmosphere furnace or a high-frequency induction heating furnace.