Nozzle Image Timing for Accurate Liquid Level Detection
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Solution Overview
Problem
Existing liquid processing apparatuses for semiconductor wafers face challenges in accurately detecting liquid levels and foreign matter within nozzles, leading to potential processing defects due to incorrect liquid levels or adhered droplets, which can result in suboptimal film thickness and drying issues.
Innovation Solution
A liquid processing apparatus equipped with a camera to capture images of nozzles at different timings, using image data to detect liquid levels and droplets by analyzing brightness and vibration patterns, and a controller to determine abnormalities and adjust processing accordingly.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If image capture is performed during liquid supply, then productivity is maintained, but measurement precision of liquid level deteriorates due to liquid flow interference
Solution Approach 1:
The patent performs image capture during periods when liquid supply is suspended, before the next supply cycle begins. The controller is configured to capture images at timing when the liquid level is stable and not affected by incoming liquid flow, thereby ensuring measurement precision without compromising overall productivity since the capture occurs during existing process intervals.
2Device complexity
If single image capture is used, then device complexity is reduced, but measurement precision of liquid level deteriorates due to inability to distinguish liquid from foreign matter
Solution Approach 1:
The system captures multiple images at different timings during the liquid supply cycle. By comparing the liquid level positions across these sequentially captured images, the system can distinguish between actual liquid levels and foreign matter, thereby improving measurement precision while using only a simple single-camera setup without complex multi-sensor systems.
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 solution enables precise detection of liquid levels and droplets, preventing processing defects by ensuring accurate resist film formation and maintaining optimal nozzle conditions, thereby enhancing the reliability of semiconductor wafer processing.
Implementation Method 1
a capturing part configured to capture an image of the nozzle so as to acquire image data
Data Source
AI summary
There is provided a liquid processing apparatus comprising: a stage on which a substrate is placed; a nozzle configured to supply a processing liquid to the substrate placed on the stage and perform a processing on the substrate; a capturing part configured to capture an image of the nozzle so as to acquire image data; and a detector configured to detect a liquid level based on a plurality of the image data acquired by the capturing part at different timings within a period in which a supply of the processing liquid from the nozzle is not performed, wherein the liquid level is formed by the processing liquid or a liquid other than the processing liquid in a processing liquid flow path provided inside the nozzle.