Substrate Cleaning Varying Liquid Supply Region
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Solution Overview
Problem
Ultrasonic cleaning methods for substrates face inefficiencies in removing particles from upper and lower regions of a substrate due to uneven distribution of cleaning liquid and ultrasonic waves, leading to varying removal efficiencies across the substrate surface.
Innovation Solution
A substrate cleaning method and system that varies the region of cleaning liquid supply within the cleaning tank with respect to the vertical level, using multiple supplying members at different positions to ensure uniform particle removal, and adjusts the supply rate and dissolved gas concentration of the cleaning liquid, along with bubble supply, to enhance cleaning efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If ultrasonic waves are radiated from below the cleaning tank, then the cleaning process is simple and energy-efficient, but particles adhering to upper and lower parts of the substrate are removed at different efficiencies
Solution Approach 1:
The cleaning tank is divided into multiple regions (upper, middle, lower) with separate cleaning liquid supply nozzles positioned at different vertical levels. Each nozzle supplies cleaning liquid to a specific region, ensuring that particles at all vertical positions on the substrate are effectively removed with uniform efficiency.
Solution Approach 2:
Different regions of the cleaning tank are provided with cleaning liquid having different properties (particularly different dissolved gas concentrations). The lower region receives cleaning liquid with higher dissolved gas concentration to enhance cavitation effect for better particle removal from lower substrate areas, while upper regions receive cleaning liquid optimized for their specific needs.
2Reliability
If cleaning liquid is continuously supplied to replace used liquid, then cleaning effectiveness is maintained, but energy is consumed and liquid consumption increases
Solution Approach 1:
The cleaning liquid supply is performed periodically rather than continuously. The supply operation is repeated multiple times during the cleaning process, with each supply cycle replacing a portion of the used cleaning liquid. This periodic replacement maintains cleaning effectiveness while significantly reducing overall liquid consumption and associated energy costs compared to continuous supply.
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 achieves uniform particle removal across the entire substrate surface with improved efficiency by optimizing the distribution of cleaning liquid and ultrasonic wave propagation, addressing the inefficiencies of traditional methods.
Implementation Method 1
generating ultrasonic waves in the cleaning liquid contained in the cleaning tank
Implementation Method 2
generating ultrasonic waves in the cleaning liquid to remove particles from a substrate
Data Source
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AI summary
A substrate cleaning method can uniformly removing particles from substrates at a high removing efficiency. The substrate cleaning method includes the steps of immersing substrates W in a cleaning liquid in a cleaning tank 12, and generating ultrasonic waves in the cleaning liquid contained in the cleaning tank. A region in the cleaning tank toward which the cleaning liquid is supplied is varied with respect to a vertical level in the step of generating ultrasonic waves in the cleaning liquid while the cleaning liquid is being supplied into the cleaning tank.