Substrate Drying with Controlled Liquid-Dry Boundary Expansion
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Solution Overview
Problem
Conventional substrate processing methods face challenges in effectively drying substrates with resist patterns, as the spin drying method can lead to residual droplets due to differing hydrophilicity levels, causing defects like watermarks.
Innovation Solution
A combination drying method is employed, where a cleaning liquid is supplied to the substrate while a dry gas is injected to form and expand a dry region, controlling the interface between the liquid and dry areas to prevent droplet residue formation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If spin drying method is used to dry the substrate, then drying speed is improved, but residual droplets are generated due to differing hydrophilicity levels causing defects
Solution Approach 1:
The patent applies local quality by injecting dry gas at specific locations (central portion and peripheral portion) of the substrate to create localized dry regions. This targeted approach addresses the varying hydrophilicity levels at different substrate areas, preventing residual droplets while maintaining efficient drying speed throughout the substrate surface.
Solution Approach 2:
The drying process is segmented into multiple regions: a first dry region formed by central gas injection, a liquid region in between, and a second dry region formed by peripheral gas injection. This segmentation allows different areas of the substrate to be dried according to their specific hydrophilicity characteristics, eliminating the defect-causing residual droplets while preserving overall drying efficiency.
2Manufacturing precision
If cleaning liquid is supplied to form a liquid layer, then cleaning effectiveness is improved, but drying complexity increases due to need to control liquid-dry interface
Solution Approach 1:
Dry gas serves as an intermediary substance that facilitates the transition from liquid cleaning layer to dry substrate surface. By injecting dry gas at controlled positions, the patent creates intermediate dry regions that gradually expand to remove the cleaning liquid, simplifying the drying process while maintaining high cleaning effectiveness through controlled interface movement.
Solution Approach 2:
The patent performs preliminary action by forming a liquid layer with controlled hydrophilicity characteristics before introducing dry gas. This preparatory step ensures that the substrate surface is properly cleaned and conditioned, making the subsequent drying process more efficient and easier to control, thereby reducing overall process complexity.
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 method reduces defects from residual droplets by maintaining a controlled dry region expansion, ensuring thorough drying and minimizing defects on substrates with varying hydrophilicity levels.
Implementation Method 1
supplying a cleaning liquid onto the substrate under processing to form a liquid layer
Implementation Method 2
supplying a gas onto the substrate under processing to partially remove the liquid layer and thus form a dry region
Data Source
AI summary
A substrate processing apparatus for cleaning and drying a substrate under processing, including supplying a cleaning liquid onto the substrate under processing to form a cleaning liquid layer, supplying a gas onto the substrate under processing to partially remove the cleaning liquid layer and thus generate a first dry region on the substrate under processing, expanding the first dry region to generate a second dry region by controlling the movement speed of the boundary between the cleaning liquid layer and the first dry region to be less than or equal to a predetermined speed, and further expanding the second dry region to generate a third dry region.