Single Crystal Ingot Scanner Optical Measurement
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Solution Overview
Problem
Existing methods for measuring surface characteristic parameters of single crystal ingots, such as notches and flats, are cumbersome, prone to false measurements, and lack precision, especially for larger ingots, leading to increased material removal and time-consuming processes.
Innovation Solution
A method involving a single crystal ingot scanner system that rotates the ingot, records angular positions and distances, calculates a background shape, and identifies deviations to define surface characteristic parameters like width, depth, and angle, providing improved precision and reduced material loss.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If traditional tactile devices or graduation scales are used to measure orientation markers, then the measurement process is simple, but the measurement precision is poor and false measurements occur
Solution Approach 1:
The patent replaces mechanical measurement systems (tactile devices, graduation scales) with an optical measurement system. The optical scanner uses light to detect the orientation marker and capture surface geometry, eliminating contact-based measurement errors and enabling non-contact, high-precision measurement of the marker's position and dimensions.
Solution Approach 2:
The patent creates a digital copy of the physical orientation marker through optical scanning. The scanner captures the marker's geometric information and creates a digital representation that can be measured and analyzed without physically touching or altering the original marker, thereby improving measurement precision while maintaining device simplicity.
2Ease of manufacture
If flats are used as orientation markers, then alignment is easier, but too much material is removed from large ingots
Solution Approach 1:
The patent employs asymmetric marker designs including notches of various types (V-shaped, U-shaped, circular) that remove minimal material while maintaining alignment functionality. The asymmetric geometry of these notches allows for easy alignment during wafer processing while preserving maximum material from the ingot.
Solution Approach 2:
The patent applies different marker types to different locations and requirements on the ingot surface. For large ingots where material preservation is critical, notches are used instead of flats. The local quality of the marker (flat vs. notch) is optimized based on the specific measurement and alignment requirements at different positions on the ingot.
3Loss of information
If multiple orientation markers are used to indicate crystal orientation and dopant type, then information completeness is improved, but measurement time increases
Solution Approach 1:
The patent merges multiple measurement functions into a single optical scanning operation. The optical scanner simultaneously captures the position, dimensions, and angular orientation of multiple markers (major flat, minor flat, notches) in one continuous measurement process, eliminating the need for separate measurement steps for each marker type.
Solution Approach 2:
The patent implements continuous optical scanning that captures all orientation marker information in an uninterrupted sequence. The scanner continuously records the geometric parameters of all markers as the ingot rotates, providing complete information about crystal orientation and dopant type without the interruptions and repeated positioning required by traditional sequential measurement methods.
4Productivity
If manual measurement methods are used, then device complexity is low, but productivity is reduced due to time-consuming processes
Solution Approach 1:
The patent replaces manual mechanical measurement with an automated optical scanning system. The optical scanner, combined with computer-controlled rotation and automated data processing, eliminates manual measurement operations and significantly increases measurement productivity while maintaining acceptable device complexity through software-based analysis.
Solution Approach 2:
The patent implements an automated measurement system that performs all measurement functions without human intervention. The optical scanner automatically captures marker information, the rotation device automatically positions the ingot, and the computer automatically processes the data to determine crystal orientation and marker dimensions, thereby maximizing productivity.
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 enhances measurement accuracy and efficiency, allowing for simultaneous measurement of multiple parameters with lower uncertainty, reducing material removal and processing time, and improving the alignment and orientation of single crystal wafers.
Implementation Method 1
an optical scanner... recording distances from a measuring point located at a measuring distance from the rotational axis to the surface of the single crystal ingot
Data Source
Figure 1~2C
Figure 3~3E
Figure 4~5
AI summary
The present invention relates to a method of obtaining a surface characteristic parameter of a longitudinal orientation marking of a single crystal ingot, to a method of producing an orientation marked single crystal ingot, and to an ingot scanner system for performing the method. The method comprises rotating a single crystal ingot around a rotational axis, recording distances from a measuring point to the surface of the single crystal ingot at the angular positions, comparing the distances with the background shape to identify distances deviating from a background shape, and registering the angular position of distances deviating from the background shape and the corresponding distances. The surface characteristic parameter is defined from consecutive angular positions having distances deviating from the background shape and the corresponding distances. The method allows determination of the surface characteristic parameter at lower uncertainty.