Ring-Shaped Protective Wall for Substrate Exhaust Flow
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Solution Overview
Problem
Existing substrate processing apparatuses face challenges in effectively preventing processing liquids from scattering and adhering back onto the substrate while also reducing the load on the exhaust apparatus due to high flow resistance in the cup's exhaust system.
Innovation Solution
A substrate processing apparatus with a ring-shaped protective wall that forms gaps between itself and the substrate and the cup's upper opening, allowing for improved gas flow and reduced flow resistance during exhaust, thereby preventing liquid re-adhesion and optimizing exhaust efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If the cover member covers the entire surface of the wafer to prevent liquid re-adhesion, then the protection effect is improved, but the flow resistance from the inlet of the intake pipe to the cup becomes large
Solution Approach 1:
The cover member is divided into a disc-shaped main body and a ring-shaped protective wall portion. The protective wall portion is positioned only above the peripheral portion of the wafer to prevent liquid re-adhesion, while the central disc-shaped portion allows gas flow through to the cup, thereby reducing overall flow resistance while maintaining protection where needed.
Solution Approach 2:
The protective wall portion is selectively positioned only above the peripheral portion of the wafer where liquid re-adhesion occurs, rather than covering the entire wafer surface. This localized approach provides protection precisely where needed while leaving the central area open for gas flow, thus resolving the contradiction between protection and flow resistance.
2Object-affected harmful factors
If the cover member covers the entire surface of the wafer to prevent liquid re-adhesion, then the protection effect is improved, but the load on the exhaust apparatus increases
Solution Approach 1:
The cover member is segmented into a disc-shaped main body and a ring-shaped protective wall portion. This segmentation allows gas to flow through the central disc area to the cup while the protective wall prevents liquid re-adhesion, thereby reducing the exhaust load compared to a full cover while maintaining protection effectiveness.
Solution Approach 2:
The protective wall portion is positioned only where liquid re-adhesion is a problem (above the peripheral portion), allowing gas flow in other areas. This localized protection reduces the overall exhaust load on the apparatus while still preventing harmful liquid re-adhesion.
3Object-affected harmful factors
If the cover member covers the entire surface of the wafer to prevent liquid re-adhesion, then the protection effect is improved, but the gas flow rate at the outlet of the narrow gap becomes insufficient
Solution Approach 1:
The cover member is divided into a disc-shaped main body and a ring-shaped protective wall portion. The disc-shaped main body allows gas flow through to the cup, ensuring sufficient gas flow rate at the narrow gap outlet, while the protective wall portion provides localized protection against liquid re-adhesion.
Solution Approach 2:
The protective wall portion is positioned only above the peripheral portion of the wafer, allowing gas flow through the central area. This localized approach maintains sufficient gas flow rate at the narrow gap outlet while providing protection precisely where liquid re-adhesion occurs.
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 apparatus effectively suppresses liquid re-adhesion onto the substrate and reduces the load on the exhaust apparatus by enhancing gas flow through the gaps, ensuring efficient processing and reduced contamination.
Implementation Method 1
when the interior space of the cup is exhausted via the exhaust port, a gas present above the substrate is introduced through the first gap and the second gap into the interior space of the cup
Data Source
AI summary
When a substrate W is processed, a ring-shaped protective wall is located above the substrate held by the substrate holding unit and extends in a circumferential direction of the substrate. A radial position of an external periphery of a lower end of the protective wall is the same as a radial position of an internal periphery of a peripheral portion of an upper surface of the substrate held by a substrate holding unit, or is located at a radial outside. A first gap is formed between the protective wall and an upper surface of the substrate, a second gap is formed between the protective wall and a wall that defines the upper opening of the cup, and when the interior space of the cup is exhausted, a gas present above the substrate is introduced through the first gap and the second gap into the interior space of the cup.