Silicon Ingot Radial Center Eccentricity Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The existing methods for manufacturing semiconductor wafers using ingots pulled by the Czochralski process face challenges in reducing the risk of defects due to slip dislocations, particularly because the low oxygen concentration regions at the outer periphery of the ingots are not effectively removed during grinding, leading to increased defects in the wafer production process.
Innovation Solution
A method that involves measuring the radial center position of the ingot at multiple locations along its longitudinal direction, setting a reference position with a predetermined eccentricity amount, and cutting the ingot into blocks based on this measurement to ensure that the outer periphery grinding removes the low oxygen concentration regions, thereby reducing the risk of slip dislocation defects during semiconductor wafer manufacturing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If outer periphery grinding is performed on the ingot in the related art, then the ingot can be processed into ingot blocks, but eccentricity occurs at the radial center position causing the low oxygen concentration region to increase
Solution Approach 1:
The patent applies preliminary action by measuring the radial center position of the ingot before performing outer periphery grinding. The measurement step is conducted in advance to identify the actual radial center position, and based on this measurement, the ingot is repositioned or the grinding parameters are adjusted accordingly. This preliminary measurement and positioning action prevents the occurrence of eccentricity during the subsequent grinding process, thereby resolving the contradiction between ease of manufacture and manufacturing precision.
2Device complexity
If the low oxygen concentration region is not removed during grinding, then the manufacturing process is simple, but the risk of defects due to slip dislocation increases
Solution Approach 1:
The patent implements feedback by measuring the radial center position of the ingot and using this measurement information to control the outer periphery grinding process. The measurement result feeds back to adjust the grinding parameters or ingot positioning, ensuring that the low oxygen concentration region is properly removed while maintaining process simplicity. This closed-loop feedback mechanism resolves the contradiction by automatically optimizing the grinding process based on actual ingot characteristics.
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 effectively reduces the low oxygen concentration regions in the ingot blocks, minimizing the risk of defects due to slip dislocations in the semiconductor wafer production process and enhancing the manufacturing efficiency by ensuring accurate cutting and grinding processes.
Implementation Method 1
a step of measuring a radial center position of the ingot at one or more locations along a longitudinal direction of the ingot
Implementation Method 2
a step of performing outer periphery grinding on each of the cut ingot blocks
Data Source
AI summary
A method for manufacturing an ingot block in which an ingot of a silicon single crystal pulled up by a Czochralski process is cut and subjected to outer periphery grinding to manufacture an ingot block of the silicon single crystal, the method including: a step of measuring a radial center position of the ingot at one or more locations along a longitudinal direction of the ingot, a step of setting a reference position at which an offset amount of the measured radial center position of the ingot is equal to or less than a predetermined eccentricity amount, a step of cutting the ingot into the ingot blocks based on the set reference position, and a step of performing outer periphery grinding on each of the cut ingot blocks.