Substrate Solution-Treatment Apparatus Flow Rate Control
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Solution Overview
Problem
Existing substrate treatment systems face issues with treatment solution wastage and imprecise control of solution amount due to solution dripping from the nozzle after supply is stopped, especially with low surface tension solutions like buffered hydrofluoric acid containing a surfactant, leading to contamination and inefficiency.
Innovation Solution
A substrate solution-treatment apparatus with a flow rate control mechanism and an opening/closing valve system that gradually reduces the flow rate before closing, preventing solution dropout and optimizing solution usage by controlling the flow rate through a detection value matching a target value, and utilizing a control part to manage the valve operations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of time
If the opening/closing valve is closed quickly to stop treatment solution supply, then the treatment time is reduced, but the treatment solution drops from the nozzle causing treatment failure and contamination
Solution Approach 1:
The flow rate control mechanism is activated before the opening/closing valve is closed to gradually reduce the treatment solution flow rate to a predetermined low value. This preliminary action ensures that when the valve closes, the solution flow is already minimized, preventing droplet formation and contamination while maintaining efficient treatment timing.
2Reliability
If a drain line is used to prevent solution dropout by allowing solution to flow to drain, then solution dropout is prevented, but treatment solution is wastefully consumed
Solution Approach 1:
Instead of discarding solution through a drain line, the flow rate control mechanism changes the flow rate parameter to a predetermined low value before valve closure. This allows the solution to be fully utilized for treatment purposes while preventing dropout, thereby eliminating wasteful consumption and enabling precise control of the total treatment solution amount.
3Reliability
If the main opening/closing valve is closed at low speed to maintain constant pressure, then solution cutoff inside nozzle is prevented, but the device complexity increases with additional control mechanisms
Solution Approach 1:
The flow rate control mechanism is integrated into the existing supply line at the downstream side of the opening/closing valve, merging the flow control function with the valve control system. This combination achieves smooth pressure transition and prevents solution cutoff without requiring separate complex control mechanisms, thereby maintaining device simplicity while ensuring reliable solution flow continuity.
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 prevents solution dropout from the nozzle, reduces wastage, and allows precise control of the solution amount applied to the substrate, enhancing treatment efficiency and minimizing contamination within the processing chamber.
Implementation Method 1
a flow rate control mechanism including a flow rate meter and a flow rate control valve installed in the supply line; the flow rate control mechanism is configured to control the flow rate control valve such that a detection value of the flow rate meter coincides with a flow rate target value
Implementation Method 2
when stopping the supply of the treatment solution from a state where the treatment solution is being supplied from the nozzle to the substrate by switching the opening/closing valve from an opened state to a closed state
Implementation Method 3
the opening/closing valve of the drain line is opened to allow a portion of the treatment solution to flow, which is flowing through the supply line, to the drain line
Implementation Method 4
the main opening/closing valve is closed at a low valve closing speed. This makes it possible to maintain a primary-side pressure of the main opening/closing valve substantially constant when closing the main opening/closing valve
Data Source
AI summary
A substrate solution-treatment apparatus includes: a substrate holding part for holding a substrate; a nozzle for supplying a treatment solution onto the substrate; a supply line; a flow rate control mechanism including a flow rate meter and a flow rate control valve installed in the supply line; an opening/closing valve installed in the supply line; and a control part for controlling operations of the flow rate control mechanism and the opening/closing valve. The flow rate control mechanism controls the flow rate control valve such that a detection value of the flow rate meter coincides with a flow rate target value provided from the control part. The control part controls the nozzle to supply the treatment solution onto the substrate with the opening/closing valve opened, and provides a first flow rate as the flow rate target value to the flow rate control mechanism.