Substrate Processing Apparatus Pressure Loss Valve Control
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Solution Overview
Problem
Existing substrate processing apparatuses suffer from contamination due to particles generated within the valve mechanism, leading to deterioration of substrate cleanliness, as particles are expelled along with the processing liquid, and filtration is insufficient to remove these particles effectively.
Innovation Solution
A substrate processing apparatus design that includes a circulation system with a filter to remove foreign matter, where the pressure loss through the supply piping is greater than the return piping, ensuring that processing liquid primarily flows through the return piping, and a discharge valve mechanism that adjusts pressure losses to prevent valve closure, maintaining the supply piping open except during abnormalities, thereby reducing particle contamination.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If a valve is used to control processing liquid flow, then the processing liquid can be supplied to the substrate, but particles are generated inside the valve due to contact between valve elements and valve seats
Solution Approach 1:
The patent extracts the valve from the processing liquid supply path and replaces it with a pump-based flow control system. The pump controls the flow rate of processing liquid without requiring the liquid to pass through a valve mechanism, thereby eliminating particle generation from valve contact while maintaining operational control.
Solution Approach 2:
The patent introduces a pump as an intermediary device between the processing liquid storage and the substrate. Instead of using a valve that directly controls liquid flow (causing particle generation), the pump indirectly controls flow by adjusting its rotation speed, eliminating the need for valve elements and seats that generate particles.
2Object-generated harmful factors
If a filter is disposed between the valve and the nozzle, then particles can be removed from the processing liquid, but one-time filtration is not able to sufficiently remove the particles
Solution Approach 1:
The patent removes the valve from the system entirely, eliminating the source of particle generation at its root. This prevents particles from entering the processing liquid in the first place, making filtration unnecessary for achieving substrate cleanliness while still maintaining a filter as a backup measure.
Solution Approach 2:
The patent prevents particle generation before it can occur by eliminating the valve mechanism that causes contact between valve elements and seats. This preliminary prevention approach is more effective than post-generation filtration, ensuring that no particles are introduced into the processing liquid stream.
3Productivity
If the valve is closed to stop processing liquid flow, then the processing liquid stays inside the valve, but particles inside the valve are not expelled and contaminate the substrate when the valve is opened
Solution Approach 1:
The patent extracts the valve from the flow control mechanism and replaces it with a pump that can be adjusted to stop flow by reducing rotation speed to zero. This eliminates the closed valve state where particles accumulate, as the pump can smoothly decelerate without trapping liquid and particles inside a closed chamber.
Solution Approach 2:
The patent uses a dynamically adjustable pump rotation speed to control processing liquid flow instead of a static valve opening/closing mechanism. The pump can be gradually slowed down to stop flow, preventing particle accumulation and eliminating the sudden expulsion of particles that occurs when a closed valve is suddenly opened.
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 significantly reduces the amount of foreign matter reaching the substrate, enhancing cleanliness and preventing droplet dripping from the nozzle during processing liquid cessation, while ensuring efficient circulation and filtration of particles back to the tank.
Implementation Method 1
a filter which removes foreign matter from the processing liquid flowing through the circulation piping
Implementation Method 2
a liquid sending device which sends the processing liquid inside the tank to the circulation piping
Implementation Method 3
circulation piping which circulates the processing liquid inside the tank
Data Source
AI summary
The substrate processing apparatus includes first supply piping which guides a processing liquid from a first branching portion to a first chemical liquid nozzle, first return piping which guides the processing liquid from the first branching portion to a tank, a first pressure-loss setting unit which sets a pressure loss so that a pressure loss through the first supply piping is larger than a pressure loss through the first return piping, and a first discharge valve which switches between a first discharge execution state in which the pressure loss through the first return piping is larger than the pressure loss through the first supply piping and a first discharge stop state in which the pressure loss through the first return piping is smaller than the pressure loss through the first supply piping.