Substrate Resist Removal End Detection Using Guard Wall Luminance
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Solution Overview
Problem
Existing methods struggle to accurately detect the end of resist removal processing on substrates due to variations in luminance values, making it difficult to determine the processing end time point, especially when using certain types of resist.
Innovation Solution
A substrate processing method that involves acquiring images of both the substrate surface and the guard's inner wall surface while supplying processing liquid, monitoring luminance values, and detecting the processing end time point based on changes in both surfaces, allowing for precise detection even when changes are insufficient on one surface alone.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If only the luminance value of the substrate surface is monitored, then the detection method is simple, but the detection accuracy is insufficient when resist removal is subtle
Solution Approach 1:
The patent combines the monitoring of substrate surface luminance with guard wall luminance into a unified detection system. By merging these two monitoring functions, the system achieves higher detection accuracy for processing end time points while managing complexity through integrated control of the image acquisition apparatus.
Solution Approach 2:
The guard wall serves as an intermediary element that reflects the processing state indirectly. By monitoring the luminance changes of the guard wall, which receives the processing liquid, the system obtains additional information about the processing end state without directly complicating the substrate monitoring.
2Loss of substance
If the amount of chemical liquid is reduced, then environmental load is decreased, but the reliability of detecting processing end is compromised
Solution Approach 1:
The system uses real-time feedback from luminance monitoring of both the substrate surface and guard wall to determine the processing end time point. This feedback mechanism allows the system to stop chemical liquid supply at the optimal moment, ensuring reliable detection while minimizing chemical liquid consumption.
Solution Approach 2:
The guard wall monitoring provides preliminary indication of processing end state before the substrate surface changes become evident. This preliminary detection allows for timely intervention to stop chemical liquid supply, preventing both over-processing and unnecessary chemical consumption.
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 method enables prompt and accurate detection of the processing end time point, reducing residue adhesion and optimizing liquid usage by switching to rinse and recovery processes at the appropriate time, thereby improving processing efficiency and reducing chemical consumption.
Implementation Method 1
an image acquiring unit that acquires an image of the surface of the substrate to be processed and an image of an inner wall surface of the guard
Implementation Method 2
a detecting unit that monitors luminance values of images acquired by the image acquiring unit and detects a processing end time point
Data Source
AI summary
A substrate processing method includes a substrate holding step of holding a substrate at a holding position surrounded by a cylindrical guard, a processing liquid supplying step of supplying a processed surface of the substrate with a processing liquid with which the processed surface of the substrate is processed while rotating the substrate held at the holding position about a rotation axis passing through a central portion of the substrate, an image acquiring step of acquiring an image of the processed surface of the substrate and an image of an inner wall surface of the guard while supplying the processing liquid to the processed surface of the substrate, and a detecting step of monitoring luminance values of the images obtained in the image acquiring step, and detecting a processing end time point at which processing of the processed surface of the substrate with the processing liquid is ended.