Ceramic Plasma Chamber Member Surface Roughness Control
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Solution Overview
Problem
Conventional plasma processing device members lack sufficient corrosion resistance to plasma generating gases, leading to particle generation and pattern loss during semiconductor manufacturing.
Innovation Solution
A ceramic member with a cylindrical shape and through hole, primarily composed of aluminum oxide, featuring a specific surface roughness and kurtosis, which reduces exposure of the grain boundary phase to plasma generating gases, thereby enhancing corrosion resistance and preventing particle generation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If mechanical processing is performed on ceramic components to improve corrosion resistance, then crystal grains are destroyed and cracks are generated, but corrosion resistance is improved
Solution Approach 1:
The invention changes the surface roughness parameters (Ra: 0.3-3.0 μm, Rmax: 10-130 μm) of the inner peripheral surface to optimize corrosion resistance. By controlling the arithmetic average roughness and maximum height of irregularities, the patent achieves reduced grain boundary exposure without requiring mechanical processing that would damage crystal grains.
2Object-generated harmful factors
If mechanical processing is performed on ceramic components, then pressing force between crystal grains is reduced, but particle generation is suppressed
Solution Approach 1:
The invention optimizes surface roughness parameters (Ra: 0.3-3.0 μm, Rmax: 10-130 μm) to reduce particle generation while maintaining crystal grain integrity. The controlled irregularities on the surface reduce grain boundary phase exposure without requiring mechanical processing that would weaken the crystal grain bonding.
3Reliability
If grain boundary phase is exposed to plasma generating gas, then corrosion occurs, but smooth surface reduces corrosion
Solution Approach 1:
The invention optimizes surface roughness parameters (Ra: 0.3-3.0 μm, Rmax: 10-130 μm) to reduce grain boundary phase exposure to plasma generating gas. The controlled surface irregularities create a morphology that minimizes direct contact between the grain boundary phase and corrosive plasma, thereby improving corrosion resistance without requiring a perfectly smooth surface.
Data Source
AI summary
A member for a plasma processing device of the present disclosure is a member for a plasma processing device made of ceramics and having a shape of a cylindrical body with a through hole in an axial direction. The ceramics is mainly composed of aluminum oxide, and has a plurality of crystal grains and a grain boundary phase that is present between the crystal grains. An inner peripheral surface of the cylindrical body has an arithmetic average roughness Ra of 1 μm or more and 3 μm or less, and an arithmetic height Rmax of 30 μm or more and 130 μm or less.