Dopant Feeder for Silicon Ingot Neck Dislocation Control
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Solution Overview
Problem
The existing methods for growing silicon single crystal ingots, such as the Czochralski method, face challenges in supporting heavy weights due to limitations in dislocation control, particularly for ingots with diameters larger than 5 mm, as the shear stress generated during the process leads to dislocation propagation, making it difficult to manage dislocations effectively for larger diameters.
Innovation Solution
Incorporating a dopant supply unit in the ingot growing apparatus that provides a dopant to the neck portion during the ingot growth process, allowing for a higher dopant concentration, which decreases dislocation propagation velocity and length, enabling the growth of ingots with larger diameters by controlling defects and supporting heavier weights.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Weight of moving object
If the diameter of the neck portion is increased to support heavier ingots, then the weight support capacity increases, but the dislocation propagation velocity increases making it difficult to control dislocations
Solution Approach 1:
The patent applies parameter changes by introducing dopants into the neck portion to alter the material properties. The dopant concentration is carefully controlled to decrease dislocation propagation velocity while maintaining the ability to support heavy ingot weights. This chemical parameter modification allows the neck portion to have larger diameter without suffering from increased dislocation propagation issues.
2Manufacturing precision
If the crystal growth rate is increased to remove dislocations, then dislocation removal effectiveness improves, but the shear stress generated increases making it difficult to maintain control
Solution Approach 1:
The dopant acts as an intermediary substance that modifies the relationship between crystal growth rate and shear stress. By introducing dopants into the neck portion, the patent creates a material state that allows higher crystal growth rates without proportionally increasing shear stress damage. The dopant concentration is optimized to achieve this balancing effect.
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
The method effectively controls dislocation propagation and increases the diameter of the neck portion, enabling the support of heavy-weight ingots, thereby improving the yield and quality of large-diameter wafers by preventing process failures and enhancing the manufacturing process.
Implementation Method 1
a dopant supply unit disposed adjacent to the pulling device and for supplying a dopant during growing of the ingot
Implementation Method 2
a pulling device pulling a silicon single crystal ingot grown from the silicon melt
Implementation Method 3
a crucible containing a silicon melt
Data Source
AI summary
Provided is an ingot growing apparatus, which includes a crucible containing a silicon melt, a pulling device pulling a silicon single crystal ingot grown from the silicon melt, and a dopant supply unit disposed adjacent to the pulling device and for supplying a dopant during growing of the ingot. The neck portion may be doped at a concentration higher than that of the ingot through the dopant supply unit. Therefore, dislocation propagation velocity may be decreased and a propagation length may be shortened.