Processing Liquid Replenishment Control for Stable Substrate Coating
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Solution Overview
Problem
Existing substrate processing systems face challenges in reducing particle generation during the replenishment of processing liquids, leading to inefficiencies in the discharge of processing liquids onto substrates due to hunting effects and particle formation from filters.
Innovation Solution
The system incorporates a control method that reduces the pressure difference between the replenishment and liquid feeding parts before opening the switching valve, and uses a filter to remove foreign matters, ensuring the processing liquid is replenished at a controlled pressure and flow rate to minimize hunting and particle generation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the switching valve is opened immediately during replenishment, then the replenishment process is simple and fast, but hunting effects occur and particles are generated from the filter
Solution Approach 1:
The system performs preliminary pressure equalization between the replenishment part and liquid feeder part before opening the switching valve. The pressure equalization part reduces the pressure difference in advance, preventing hunting effects and particle generation when the valve opens, while still allowing fast replenishment afterward
2Manufacturing precision
If a filter is used to remove foreign matters, then the processing liquid purity is improved, but particles are generated from the filter during replenishment
Solution Approach 1:
The pressure equalization part equalizes pressures before opening the switching valve, preventing sudden liquid surge through the filter that would cause particle generation. This allows the filter to continue removing foreign matters effectively without generating particles during replenishment
3Stability of the object's composition
If the pressure difference is reduced before opening the switching valve, then hunting effects are suppressed, but the replenishment preparation time increases
Solution Approach 1:
The pressure equalization part controls the pressure difference parameter to be within a predetermined range before opening the switching valve. This optimized parameter control achieves pressure stability to prevent hunting effects while minimizing the time required for preparation
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 approach effectively reduces particle generation in the processing liquid discharged onto substrates, enhancing the efficiency and quality of the coating and developing process by suppressing hunting effects and maintaining stable liquid pressures.
Implementation Method 1
a filter configured to remove foreign matters contained in the processing liquid replenished from the replenishment part to the liquid feeder
Data Source
AI summary
A substrate processing apparatus includes a discharge part including a nozzle configured to discharge a processing liquid onto a substrate; a liquid feeder configured to feed the processing liquid to the discharge part; a replenishment part configured to replenish the liquid feeder with the processing liquid to be fed to the discharge part; a connector including a switching valve configured to open/close a flow path between the replenishment part and the liquid feeder; a filter configured to remove foreign matters contained in the processing liquid; a replenishment preparation part configured to open the switching valve after reducing a pressure difference between the inside of the replenishment part and the liquid feeder; and a replenishment controller configured to start replenishment of the processing liquid from the replenishment part to the liquid feeder in a state in which the switching valve is opened by the replenishment preparation part.