Melt Surface Position Control Using Dual Measurement Switching
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing silicon single crystal manufacturing processes face challenges in accurately controlling the melt surface position due to measurement abnormalities, such as equipment failures or erroneous readings, which can lead to unstable production and defects in silicon single crystals.
Innovation Solution
A single-crystal manufacturing apparatus and method that utilize at least two different melt surface position measuring means to simultaneously measure the melt surface position, select a primary measuring means for control, and switch to a secondary means if an abnormality is detected, ensuring stable control by determining measurement abnormalities through changes in melt surface position values over time.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a single melt surface position measuring means is used, then the device complexity is reduced, but the reliability of melt surface position control deteriorates due to measurement abnormalities
Solution Approach 1:
The patent applies preliminary action by preparing a plurality of melt surface position measuring means (first measuring means and second measuring means) in advance before operation. When a measurement abnormality occurs in the currently used measuring means, the system can immediately switch to a standby measuring means without interruption to the crystal growth process, thereby maintaining control reliability while avoiding the complexity of complex error detection and correction mechanisms
Solution Approach 2:
The patent implements beforehand cushioning by having a standby measuring means ready in advance to compensate for potential failures of the active measuring means. This redundancy acts as a cushion against measurement abnormalities, ensuring that control reliability is maintained even when one measuring means fails, without requiring complex real-time diagnostics or system reconfiguration
2Manufacturing precision
If melt surface position is not accurately controlled, then the manufacturing process is simpler, but the quality of silicon single crystal deteriorates due to grown-in defects
Solution Approach 1:
The system performs preliminary action by continuously monitoring melt surface position with multiple measuring means and maintaining a standby measuring means ready. This ensures that even if one measuring means fails, the melt surface position can still be accurately controlled without interrupting the crystal growth process, thereby achieving high manufacturing precision without requiring complex real-time switching mechanisms
Solution Approach 2:
The patent applies feedback by using the measuring means to detect melt surface position and feeding this information back to the crucible ascending/descending control. The system calculates the difference between current and target melt surface positions and adjusts the crucible position accordingly, ensuring accurate melt surface position control while maintaining relatively simple control logic
3Manufacturing precision
If crucible position is adjusted frequently to maintain melt surface position, then manufacturing precision is improved, but productivity deteriorates due to increased control operations
Solution Approach 1:
The patent implements continuity of useful action by ensuring that melt surface position control operates continuously without interruption. When a measurement abnormality is detected, the system switches to a standby measuring means and continues control operations seamlessly, avoiding pauses or interruptions in crystal growth that would reduce productivity while maintaining manufacturing precision
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 allows for stable control of the melt surface position even during measurement abnormalities, preventing defects and ensuring high-quality silicon single crystal production by rapidly switching to a backup measuring means when anomalies occur.
Implementation Method 1
a CCD camera configured to measure a melt surface position from the outside of a furnace is provided to an outer portion of a chamber and the melt surface position is accurately controlled to a fixed position based on a measurement result from an image provided by the CCD camera
Data Source
AI summary
A single-crystal manufacturing apparatus including: at least two different melt surface position measuring means for measuring a melt surface position of a material melt; controlling means for controlling the melt surface position based on the measured melt surface position; and determining means for determining whether a measurement abnormality has occurred in the melt surface position measuring means, the apparatus being characterized in that the melt surface position is measured by the plurality of melt surface position measuring means at the same time, one melt surface position measuring means adopted for control over the melt surface position is selected from the plurality of melt surface position measuring means, and the melt surface position measuring means adopted for control over the melt surface position is switched to another melt surface position measuring means when the determining means determines that a measurement abnormality has occurred in the selected melt surface measuring means.