Substrate Treatment Airflow Separation for Uniform Liquid Films
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Solution Overview
Problem
The existing substrate treating apparatuses face issues with air flow stagnation and vortex formation when treating rotating substrates, leading to non-uniform film thickness and contamination due to the collision of air flows with the outer cup, which complicates the evacuation of air and reintroduces contaminants to the substrate.
Innovation Solution
The apparatus incorporates a first and second gas-liquid separator within the processing container, along with an air flow guide duct, to manage air flow tangentially and prevent stagnation, ensuring smooth air flow evacuation and uniform liquid film distribution across the substrate.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the substrate rotates at high speed to improve treatment efficiency, then productivity increases, but air flow stagnation and vortex formation worsen due to centrifugal force
Solution Approach 1:
The exhaust system is segmented into multiple exhaust holes distributed around the inner cup, allowing air flow to be evacuated at different locations and reducing stagnation zones that would form with a single exhaust point
Solution Approach 2:
The inner cup acts as an intermediary structure between the substrate and outer cup, creating a controlled air flow path that guides centrifugal air flow toward the exhaust holes without direct collision with the outer cup wall
2Device complexity
If the air flow is exhausted through the outer cup to simplify the exhaust structure, then device complexity decreases, but film thickness uniformity worsens due to air flow collision and stagnation
Solution Approach 1:
The exhaust function is segmented into multiple holes in the inner cup rather than a single exhaust point, distributing the air flow evacuation across multiple locations to prevent localized stagnation that would cause film thickness variations
Solution Approach 2:
The exhaust holes are positioned at the bottom of the inner cup, utilizing the vertical dimension to evacuate air flow before it can collide with the outer cup wall, thereby maintaining horizontal air flow uniformity across the substrate surface
3Ease of operation
If the exhaust tube is positioned at the bottom of the inner space to simplify evacuation, then ease of operation improves, but contamination increases due to vortex formation and air flow reversal
Solution Approach 1:
The inner cup serves as an intermediary exhaust structure with its own exhaust holes, preventing direct communication between the bottom exhaust tube and the substrate area, thereby blocking the reverse flow path that would transport contaminants back to the substrate
Solution Approach 2:
The exhaust function is extracted from the outer cup structure and implemented separately in the inner cup, allowing independent optimization of the exhaust path to prevent contaminant recirculation while maintaining evacuation efficiency
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 ensures uniform liquid film thickness and prevents re-contamination by efficiently managing air flow and liquid distribution, improving the overall treatment process for substrates.
Implementation Method 1
an air flow 84 on the surface of the substrate W flows from the center of the substrate W toward the edge thereof along the rotating direction of the substrate W by the centrifugal force
Implementation Method 2
When the substrate treating apparatus 1 treats the substrate W while supplying the treating liquid 82 on the rotating substrate W
Data Source
AI summary
An apparatus for treating a substrate, the apparatus comprising: a processing container having an inner space; a support unit having a support plate configured to support and rotate the substrate in the inner space; a liquid supply unit supplying treating liquid to the substrate supported by the support unit; and an exhaust unit exhausting an air flow in the inner space, wherein the processing container includes a bottom wall and a side wall extending from the outside end of the bottom wall, the processing container including a first gas-liquid separator provided at the side wall.