Processing Liquid Supply Cooling for Nozzle Dropout Control
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Solution Overview
Problem
In substrate processing, the increased diameter of nozzle outlets leads to significant processing liquid dropout, especially with low surface tension fluids like surfactants or organic solvents, resulting in substrate contamination and reduced productivity due to inefficient suck-back mechanisms.
Innovation Solution
A substrate processing apparatus with a processing liquid supply unit that includes a cooler to reduce the volume of the processing liquid by cooling it, and a tubular member surrounding the supply line to supply coolant, thereby enhancing the suck-back efficiency and preventing liquid dropout.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If the nozzle outlet diameter is increased to increase the amount of processing liquid discharged, then the processing liquid supply amount is improved, but the processing liquid dropout is significantly increased
Solution Approach 1:
The patent changes the temperature parameter of the processing liquid by introducing a cooling mechanism. The cooling unit cools the processing liquid in the supply line, which increases the liquid's viscosity and surface tension, thereby preventing dropout while maintaining adequate supply amount through the larger nozzle outlet.
2Reliability
If processing liquid with low surface tension (e.g., surfactants, organic solvents) is used, then the cleaning effectiveness is improved, but the liquid flows into the nozzle by gravity causing leakage
Solution Approach 1:
The patent applies temperature parameter change by cooling the low surface tension processing liquid. This temperature reduction increases the liquid's surface tension and viscosity, enabling it to be retained in the nozzle without gravity-induced leakage while preserving its cleaning effectiveness.
Solution Approach 2:
The patent replaces the reliance on mechanical suction (suck-back valve) with a thermal field approach. By using the cooling unit to modify the liquid's physical properties, the system achieves liquid retention without depending solely on mechanical suction mechanisms.
3Object-generated harmful factors
If the suck-back valve is used to remove processing liquid from the nozzle, then the liquid leakage is prevented, but inefficient suck-back causes Taylor cone and air layer formation
Solution Approach 1:
The patent performs preliminary cooling of the processing liquid before it reaches the nozzle. This pre-cooling increases the liquid's viscosity and surface tension in advance, allowing it to be retained without aggressive suck-back, thereby preventing Taylor cone and air layer formation that would compromise substrate quality.
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 described solution effectively prevents processing liquid dropout, reduces contamination risks, and enhances substrate processing efficiency by ensuring efficient suck-back of low surface tension liquids, thus maintaining the quality and productivity of the substrate processing.
Implementation Method 1
a cooler configured to cool the processing liquid in the supply line
Implementation Method 2
the cooler may be configured to control at least one of a temperature, a supply flow volume, a supply time, and a heat transfer area of the coolant supplied to the inside space of the tubular member
Data Source
AI summary
A substrate processing apparatus a processing liquid supply unit includes a nozzle supplying a processing liquid onto the substrate, a supply line connected to the nozzle to supply the processing liquid to the nozzle, and a cooler cooling the processing liquid. A volume of the processing liquid is reduced by the cooler so that the processing liquid may be sucked.