Alpha-Silicon Carbide Member Plasma Resistance

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Solution Overview

Problem

The high cost and limited plasma resistance of silicon carbide (SiC) members used in plasma processing apparatuses, particularly those using β-SiC, lead to increased production costs and potential chamber contamination issues due to metal impurities when using α-SiC.

Innovation Solution

A silicon carbide member produced using α-SiC with an oxide-based sintering aid comprising Al2O3 and Y2O3, where the total amount of Al2O3 and Y2O3 is between 3 to 15 weight parts, with Y2O3 being one to two times the amount of Al2O3, and sintered at temperatures between 1850°C to 2200°C, resulting in a dense sintered body with improved plasma resistance and reduced metal impurities.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If β-SiC is used for SiC members in plasma processing apparatuses, then plasma resistance is improved, but production cost increases and metal impurities may contaminate the chamber

Engineering Contradiction:
Improveplasma resistanceVSAvoidmetal impurity contamination
Core Design Contradiction:
ReliabilityVSObject-generated harmful factors

Solution Approach 1:

The invention changes the crystal structure parameter of silicon carbide from β-phase to α-phase, which fundamentally alters the material properties. α-SiC exhibits superior plasma resistance and significantly reduces metal impurity contamination while maintaining structural integrity in plasma processing environments

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The invention creates a composite structure by combining α-SiC particles with specific binders and sintering aids. This composite approach enhances the plasma resistance and reduces metal impurity release compared to pure β-SiC, while maintaining mechanical strength and electrical properties

Inventive Principle:
Principle #40Composite materials

2Ease of manufacture

If α-SiC is used for SiC members, then production cost is reduced, but plasma resistance and chamber contamination resistance are worsened

Engineering Contradiction:
Improveproduction costVSAvoidplasma resistance
Core Design Contradiction:
Ease of manufactureVSReliability

Solution Approach 1:

The invention changes the crystal structure parameter of silicon carbide from β-phase to α-phase, which fundamentally alters the material properties. α-SiC exhibits superior plasma resistance and significantly reduces metal impurity contamination while maintaining structural integrity in plasma processing environments

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The invention creates a composite structure by combining α-SiC particles with specific binders and sintering aids. This composite approach enhances the plasma resistance and reduces metal impurity release compared to pure β-SiC, while maintaining mechanical strength and electrical properties

Inventive Principle:
Principle #40Composite materials

3Manufacturing precision

If sintering temperature is increased to improve density, then manufacturing precision is improved, but energy consumption and risk of metal impurity contamination increase

Engineering Contradiction:
ImprovedensityVSAvoidsintering energy consumption
Core Design Contradiction:
Manufacturing precisionVSUse of energy by moving object

Solution Approach 1:

The invention changes the crystal structure parameter of silicon carbide from β-phase to α-phase, which fundamentally alters the material properties. α-SiC exhibits superior plasma resistance and significantly reduces metal impurity contamination while maintaining structural integrity in plasma processing environments

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The invention creates a composite structure by combining α-SiC particles with specific binders and sintering aids. This composite approach enhances the plasma resistance and reduces metal impurity release compared to pure β-SiC, while maintaining mechanical strength and electrical properties

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

The approach enables the production of SiC members with high plasma resistance at a lower cost, improving durability and reducing production costs while maintaining excellent plasma resistance and surface roughness, thus suitable for use in plasma processing apparatuses.

Implementation Method 1

sintered at temperatures between 1850°C to 2200°C, resulting in a dense sintered body

Methodology Applied
Scientific EffectSintering: Sintering

Implementation Method 2

a silicon carbide member produced using α-SiC with an oxide-based sintering aid comprising Al2O3 and Y2O3, where the total amount of Al2O3 and Y2O3 is between 3 to 15 weight parts

Methodology Applied
Scientific EffectHot pressing:

Data Source

PatentEP3279923B1Silicon carbide member for plasma treatment devices, and method for manufacturing same
Publication Date: 2022.05.04 HOKURIKU SEIKEI IND
  • EP3279923B1 patent drawingFigure 1
  • EP3279923B1 patent drawingFigure 2A~2D
  • EP3279923B1 patent drawingFigure 3~4

AI summary

It is an object of the present invention to provide a low cost and durable silicon carbide member for a plasma processing apparatus. A silicon carbide member for a plasma processing apparatus of the present invention is obtained by mixing an α-silicon carbide powder having an average particle size of 0.3 to 3 µm, wherein an amount of metal impurities in the α-silicon carbide powder is reduced to 20 ppm or less, and a sintering aid comprising B4C in amount of 0.5 to 5 weight parts or Al2O3 and Y2O3 in total amount of 3 to 15 weight parts; sintering a mixture of the α-silicon carbide powder and the sintering aid in an argon atmosphere furnace or a high-frequency dielectric heating furnace; and then processing the resulting sintered body.