Ring Cover Substrate Processing Reduces Exhaust Flow Resistance
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Solution Overview
Problem
Existing substrate processing apparatuses face challenges in effectively preventing processing liquids from being scattered and adhered back onto the substrate due to high flow resistance in the exhaust system, which limits the gas flow rate and efficiency of liquid processing.
Innovation Solution
A substrate processing apparatus with a ring-shaped cover member that exposes the central portion of the substrate, reducing flow resistance and allowing a gas flow from above the cup into the interior space through a gap between the cover member and the substrate, enhancing the exhaust efficiency and preventing liquid re-adhesion.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If a disc-shaped cover member covers the entire surface of the wafer, then the mist of chemical liquid is prevented from being attached again to the upper surface of the wafer, but the flow resistance from the inlet of the intake pipe to the cup becomes large, making it difficult to obtain sufficient gas flow rate at the outlet of the narrow gap
Solution Approach 1:
The cover member is changed from a disc shape covering the entire wafer surface to a ring shape that only covers the peripheral portion of the wafer. This segmentation allows the central portion to remain exposed, creating a direct gas flow path from the intake pipe to the cup through the center of the wafer, thereby reducing flow resistance while still preventing liquid re-adhesion at the periphery where it occurs most
Solution Approach 2:
The central portion of the cover member is removed or extracted, transforming it from a solid disc to a ring structure. This extraction creates an open passage through the center of the wafer, allowing gas to flow directly from the intake pipe to the cup without having to pass through the entire covered area, thus significantly reducing flow resistance
2Productivity
If the interior space of the cup is exhausted strongly to overcome high flow resistance, then sufficient gas flow rate can be obtained, but the load on the exhaust apparatus increases
Solution Approach 1:
By segmenting the cover member into a ring shape with an open center, the gas flow path is optimized to reduce resistance. This allows sufficient gas flow rate to be achieved with lower exhaust power, as the gas can flow more freely through the exposed central portion of the wafer directly to the cup
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 design reduces the load on the exhaust apparatus and effectively prevents processing liquids from re-adhering to the substrate, ensuring efficient substrate cleaning while maintaining sufficient exhaust capability even with lower exhaust forces.
Implementation Method 1
the interior space of the cup is at a negative pressure by being evacuated, a down flow of clean air flowing through a housing is sucked from the intake pipe, flows through a space between the upper surface of the wafer and the lower surface of the cover member towards the peripheral portion of the wafer
Implementation Method 2
a manufacturing process of semiconductor devices includes a peripheral portion cleaning process of removing an unnecessary film or contaminants from a peripheral portion of a semiconductor wafer by supplying a processing liquid such as a chemical liquid to the peripheral portion of the wafer while rotating the wafer
Data Source
AI summary
When a substrate W is processed, a cover member covers a peripheral portion of the upper surface of the substrate held by the substrate holding unit, and a central portion of the substrate located at an inner position than the peripheral portion in a radial direction is exposed without being covered by the cover member. A gap is formed between the lower surface of the cover member and the peripheral portion of the upper surface of the substrate held by the substrate holding unit. When the interior space of the cup is exhausted, a gas present above the interior space of the cup is introduced from a space enclosed by the internal peripheral surface of the cover member through the gap into the interior space of the cup.