Composite Plasma Source Chamber for Fluorine-Induced Particle Control
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Solution Overview
Problem
Conventional plasma sources experience particle generation due to fluorination of chamber walls, particularly at locations with high gas residence time and density, leading to aluminum fluoride peeling and particle formation, which contaminates the reactor.
Innovation Solution
The plasma source incorporates a ceramic member made of yttria sintered body at the downstream side to delimit the gas flow, combined with a metal member for the upstream side, and uses a stress buffer to manage thermal expansion, preventing fluorine components from entering the chamber wall and reducing particle generation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If the chamber wall is made of metal (aluminum), then thermal conductivity and structural strength are improved, but fluorine components cause fluorination and particle generation
Solution Approach 1:
The chamber is constructed using a composite structure combining metal members (for strength and thermal conductivity) and ceramic members (for fluorine resistance). This composite approach allows the system to simultaneously achieve structural integrity and resistance to fluorine-induced particle generation.
Solution Approach 2:
A stress buffer member is introduced as an intermediary component between the metal and ceramic members. This stress buffer mediates the thermal expansion differences between dissimilar materials, preventing stress concentration that would lead to cracking and particle generation while maintaining the composite structure's integrity.
2Object-generated harmful factors
If fluororesin coating is applied to the chamber wall, then particle generation is suppressed, but coating durability and structural integrity are compromised
Solution Approach 1:
Instead of relying on fluororesin coating, the invention uses an uncoated ceramic member that inherently resists fluorine. This eliminates coating durability issues while maintaining particle generation suppression, as the ceramic material itself provides the necessary chemical resistance.
3Object-generated harmful factors
If ceramic member is used for the entire chamber, then fluorine resistance is improved, but thermal conductivity and ease of manufacture are reduced
Solution Approach 1:
The ceramic member is strategically positioned only in the downstream region where fluorine resistance is most critical. The metal member handles regions requiring high thermal conductivity and structural strength. This localized application optimizes both fluorine resistance and manufacturing ease.
Solution Approach 2:
The chamber uses a composite design with metal and ceramic members in specific configurations. This allows each material to be used where its properties are most beneficial, simplifying manufacturing compared to an all-ceramic design while maintaining necessary fluorine resistance.
4Stability of the object's composition
If stress buffer is added between metal and ceramic members, then thermal expansion stress is reduced, but device complexity increases
Solution Approach 1:
The stress buffer acts as a mediator between metal and ceramic members with incompatible thermal expansion properties. By introducing this intermediate layer, the system accommodates differential expansion without cracking, and the buffer's material properties are selected to provide stress relief.
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
This configuration effectively suppresses particle generation by enhancing corrosion resistance and durability, ensuring clean operation of the reactor by minimizing fluorine-induced wall degradation.
Implementation Method 1
a power supply device configured to supply a power for plasma generation into a chamber, wherein the chamber includes the metal member and the ceramic member, and is configured to discharge an activated gas generated by producing plasma from the processing gas
Implementation Method 2
a ceramic member having an outlet and forming a wall that delimits a downstream flow of the processing gas discharged from the outlet
Implementation Method 3
the plasma source incorporates a ceramic member made of yttria sintered body at the downstream side to delimit the gas flow, combined with a metal member for the upstream side, and uses a stress buffer to manage thermal expansion
Data Source
AI summary
A plasma source comprises a metal member having an inlet and forming a wall that delimits an upstream flow of a processing gas supplied from the inlet, a ceramic member having an outlet and forming a wall that delimits a downstream flow of the processing gas discharged from the outlet, and a power supply device configured to supply a power for plasma generation into a chamber. The chamber includes the metal member and the ceramic member, and is configured to discharge an activated gas generated by producing plasma from the processing gas to the outside of the chamber through the outlet.