Liquid Nozzle Port Imaging for Foreign Matter Detection
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Solution Overview
Problem
Existing substrate processing apparatuses face challenges in accurately determining abnormalities, such as foreign matter at the discharging port of a liquid nozzle, which can lead to unnecessary or missed corrective actions, due to inappropriate threshold settings, resulting in potential defects on substrates during processing.
Innovation Solution
A method that involves imaging the discharging port of a liquid nozzle, acquiring size or position data of foreign matter, and using a history of data to judge abnormalities by meeting specific criteria, including continuous acquisition thresholds, to accurately determine the likelihood of foreign matter falling onto the substrate, thereby preventing defects.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a predetermined threshold is used to judge liquid suspending, then the judgment process is simple, but the accuracy of abnormality detection is poor leading to false positives or negatives
Solution Approach 1:
The system performs preliminary imaging and size data acquisition for each substrate before making the final abnormality judgment. By preparing the data in advance and establishing a history of size data, the system can make more accurate judgments based on continuous patterns rather than single-point measurements, thereby improving detection accuracy without requiring complex real-time analysis mechanisms.
Solution Approach 2:
The system establishes a feedback mechanism by continuously acquiring size data for multiple substrates and comparing current measurements against historical data. The judgment is made based on whether the number of continuous acquisitions exceeding the threshold reaches a predetermined value, creating a feedback loop that improves detection accuracy by considering trends over time rather than isolated measurements.
2Reliability
If imaging and size data acquisition is performed for each substrate, then the detection capability is improved, but the processing time increases
Solution Approach 1:
The imaging and size data acquisition are performed as preliminary steps for each substrate in the production flow. By establishing this routine preliminary action, the system accumulates historical data that enables more reliable abnormality judgments over time, while the predetermined threshold and continuous acquisition count criteria ensure that the additional processing time is used efficiently to improve rather than hinder production throughput.
Solution Approach 2:
The system changes the parameter evaluation approach by not relying on single-substrate measurements but instead using a sequence of measurements with predetermined thresholds and continuous acquisition counts. This parameter change transforms the judgment from a time-consuming complex analysis to a streamlined process that evaluates trends across multiple substrates, improving reliability without proportionally increasing processing time.
3Measurement precision
If a single threshold value is used for judgment, then the control process is simple, but it cannot distinguish between small and large amounts of liquid suspending
Solution Approach 1:
The judgment system is segmented into multiple components: a size threshold for detecting liquid suspending, a continuous acquisition count threshold, and a predetermined value threshold for confirming abnormalities. This segmentation allows the system to distinguish between small and large amounts of liquid suspending by evaluating whether measurements exceed the size threshold and persist for the required number of continuous acquisitions, providing quantification precision without requiring a single complex threshold.
Solution Approach 2:
The system uses a predetermined value that may be higher than the minimum needed to detect an abnormality, requiring multiple continuous acquisitions to confirm the condition. This excessive action approach ensures that small, transient variations in liquid suspending do not trigger false alarms, while still maintaining the ability to detect and respond to significant abnormality conditions through the layered threshold structure.
Data Source
AI summary
In one embodiment, a liquid treatment method includes (A) imaging a discharging port part of the liquid nozzle each time the discharging process is performed to one substrate, and acquiring, from images thus obtained, size data on foreign matter possibly present at the discharging port part; and (B) based on a history of the size data arranged in chronological order, judging whether an abnormality in substrate-processing has occurred. In the item (B), if the number of continuous acquisition, indicating how many times the size data not smaller than a first threshold value has been acquired continuously, exceeds a predetermined value, then judging that an abnormality in substrate-processing has occurred.