Ceramic Gas Nozzle Surface Profile Control for Particle Suppression
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Solution Overview
Problem
Ceramic sintered gas nozzles used in plasma apparatuses for semiconductor and liquid crystal manufacturing are prone to surface damage during processing, leading to particle fallout and defects on substrates due to exposure to corrosive gases, which existing methods fail to adequately prevent.
Innovation Solution
A gas nozzle with a columnar ceramic sintered body featuring through-holes and an exhaust port, where the mean width of profile elements on the end surface is set to 5 times or more the average crystalline grain diameter, and a manufacturing method involving first and second lapping processes using different polishing agents to minimize surface damage and particle fallout.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Shape
If grinding processing and/or polishing processing is performed on a ceramic sintered body to obtain a desired shape, then the desired shape is achieved, but the surface of the ceramic sintered body is damaged and particles are liable to fall off
Solution Approach 1:
The invention changes the surface roughness parameter by controlling the mean width of profile elements (Rsm) to be 5 times or more the average crystalline grain diameter. This parameter control prevents particle fallout while maintaining the desired shape achieved through grinding and polishing processes.
2Ease of operation
If the end surface of the gas nozzle is exposed to corrosive gas in the reaction chamber, then the gas nozzle performs its function, but the end surface is damaged and particles are liable to fall off
Solution Approach 1:
The invention modifies the surface morphology parameter (Rsm ≥ 5 times crystalline grain diameter) to create a surface structure that resists corrosive gas damage. This parameter change allows the end surface to maintain its integrity while performing gas flow functions in the corrosive environment.
3Strength
If particles fall off from the gas nozzle surface, then the gas nozzle structure remains, but defects are generated on the substrate
Solution Approach 1:
The invention changes the surface roughness parameter (Rsm) to create a surface structure where particles are less likely to detach. By controlling the mean width of profile elements to be 5 times or more the crystalline grain diameter, the surface maintains structural integrity while preventing particle contamination of the substrate.
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 solution effectively suppresses particle fallout from the nozzle surfaces, reducing defects on substrates during plasma processing by enhancing plasma resistance and maintaining the integrity of the ceramic sintered body.
Implementation Method 1
a columnar main body formed of a ceramic sintered body
Implementation Method 2
performing first lapping processing on one end surface of the main-body sintered body using a first polishing agent; and forming a columnar main body from the ceramic sintered body provided with the through-hole formed therein through which a gas flows by performing second lapping processing using a second polishing agent
Data Source
AI summary
[Object] To provide a gas nozzle which meets a requirement to suppress the fall of particles.[Solution] A gas nozzle 4 according to an aspect of the present invention includes a columnar main body 13 formed of a ceramic sintered body provided with a through-hole 12 formed therein through which a gas flows, an exhaust port 15 of the through-hole 12 for the gas is formed in one end surface S1 of the main body 13, and the mean width of the profile elements (Rsm) of the one end surface S1 is 5 times or more the average crystalline grain diameter of the ceramic sintered body.