Silicon Crystal Pulling With Quartz Crucible Deformation Detection
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Solution Overview
Problem
Existing methods lack the ability to quantitatively evaluate the deformation or eccentricity of quartz crucibles during silicon single crystal production, leading to potential accidents and quality issues in silicon wafers due to crucible deformation.
Innovation Solution
A method and apparatus that acquire images of the quartz crucible's mirror image on the silicon melt surface and analyze the temporal changes in the crucible's position to objectively assess deformation or eccentricity, using a camera and image processor to calculate the amount of deformation or eccentricity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If visual observation by operator is used to assess crucible deformation, then the assessment can be performed during the process, but the evaluation cannot be quantitative and is subjective
Solution Approach 1:
The patent uses image capture to create a visual copy of the crucible's mirror image, replacing subjective visual observation with objective image data that can be quantitatively analyzed. The camera system captures the mirror image reflected on the melt surface, creating a reproducible record of crucible position and shape.
Solution Approach 2:
The patent replaces the mechanical/physical act of visual observation by an operator with an optical detection system (camera) and image processing system. This substitution transforms the assessment from a subjective human task to an objective automated measurement process.
2Reliability
If no deformation monitoring is performed, then the process can continue without interruption, but accidents and quality deterioration may occur
Solution Approach 1:
The patent implements a feedback mechanism where the captured mirror image is analyzed to detect crucible deformation, and this information is used to make decisions about process continuation or interruption. The system provides real-time feedback on crucible condition, enabling proactive safety management.
Solution Approach 2:
The patent performs deformation assessment during the melting process before critical failures occur. By monitoring the mirror image continuously, the system can detect early signs of crucible deformation and take preventive action before accidents happen or quality deteriorates.
3Measurement precision
If the crucible is deformed during raw material melting, then the upper end may collapse inward, but detection is difficult without proper measurement methods
Solution Approach 1:
The patent uses the melt surface as an intermediary to reflect the crucible's mirror image, making the crucible's shape and position visible without direct line-of-sight observation. This indirect measurement method overcomes the difficulty of directly observing crucible deformation in the high-temperature environment.
Solution Approach 2:
The patent exploits the reflective properties of the melt surface to create a visual indicator (mirror image) of the crucible's condition. The mirror image acts as a visual marker that changes position and shape in response to crucible deformation, making detection possible.
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
Enables quantitative evaluation of crucible deformation, preventing accidents and improving the quality and yield of silicon single crystals and wafers by detecting and addressing crucible issues early in the process.
Implementation Method 1
acquiring images including a mirror image of the quartz crucible reflected on a melt surface of the silicon melt
Data Source
AI summary
A method and apparatus for manufacturing a silicon single crystal by pulling a silicon single crystal from a silicon melt in a quartz crucible, wherein images including a mirror image of the quartz crucible reflected on a melt surface of the silicon melt are acquired at predetermined time intervals, and deformation or eccentricity of the quartz crucible is evaluated from temporal changes of the position of the mirror image of the quartz crucible captured in a plurality of images that are acquired while the quartz crucible rotates at least once.