Movable Heater Oxygen Gap Control in Single Crystal Furnace
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Solution Overview
Problem
Existing methods for manufacturing single-crystal silicon ingots in single crystal growing furnaces face challenges in balancing oxygen content for higher quality crystals, where higher oxygen content is beneficial for seeding survival but lower oxygen content is necessary for ingot quality during constant-diameter growth.
Innovation Solution
The method involves a single crystal growing furnace with a heat insulation cylinder and a heater that can move relative to a support ring to adjust an oxygen passing gap. This gap is set to a larger first distance during seeding to increase oxygen content and a smaller second distance during constant-diameter growth to reduce oxygen content, thereby optimizing ingot quality and survival rate.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the oxygen passing gap is enlarged to increase oxygen content, then the seeding survival rate is improved, but the ingot quality deteriorates due to higher oxygen content
Solution Approach 1:
The heater is designed to be movable relative to the support ring, allowing dynamic adjustment of the oxygen passing gap during different growth stages. During seeding, the heater is positioned to create a larger gap for higher oxygen content, improving survival rate. During constant-diameter growth, the heater is repositioned to create a smaller gap for lower oxygen content, improving ingot quality.
Solution Approach 2:
The patent changes the physical parameter of the oxygen passing gap distance to control oxygen content in the molten silicon. By adjusting the distance between the heater top and support ring bottom, the system can increase oxygen content during seeding and decrease it during constant-diameter growth, resolving the contradiction between survival rate and ingot quality.
2Manufacturing precision
If the oxygen passing gap is reduced to lower oxygen content, then the ingot quality is improved, but the seeding survival rate decreases due to lower oxygen content
Solution Approach 1:
The movable heater design enables the system to adapt to different process requirements at different stages. The heater can be dynamically repositioned to reduce the oxygen passing gap during constant-diameter growth for improved ingot quality, while maintaining a larger gap during seeding for high survival rate.
Solution Approach 2:
The patent employs parameter change by adjusting the oxygen passing gap distance according to the growth stage. The distance parameter is increased during seeding to ensure survival and decreased during constant-diameter growth to ensure quality, thereby resolving the contradiction.
3Device complexity
If a fixed oxygen passing gap is used, then the device complexity is reduced, but the ability to optimize for different growth stages is lost
Solution Approach 1:
The heater is designed with movable positioning capability relative to the support ring, allowing adjustment of the oxygen passing gap during different growth stages. This dynamic adjustment mechanism, while adding some structural complexity, enables the system to optimize oxygen content for both seeding and constant-diameter growth stages.
Solution Approach 2:
The patent implements parameter change capability through the movable heater design, allowing the oxygen passing gap distance to be adjusted according to process requirements. This enables optimization of oxygen content for different growth stages despite the increased device complexity.
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 increases the seeding survival rate and productivity by maintaining higher oxygen content during seeding and improving the quality of the single-crystal silicon ingot by reducing oxygen content during constant-diameter growth.
Implementation Method 1
silicon melting
Implementation Method 2
a distance between a top of the heater and a bottom of the support ring is an oxygen passing gap
Data Source
AI summary
Provided are a method for manufacturing a single-crystal silicon ingot and a single crystal growing furnace. The furnace includes a furnace body, a heat insulation cylinder, a heater, and a crucible. The heat insulation cylinder is arranged in the furnace body. The heater is arranged in the heat insulation cylinder and located on a periphery of the crucible. The heat insulation cylinder includes an upper heat insulation cylinder, a middle heat insulation cylinder, a lower heat insulation cylinder, and a support ring. The support ring is located between the upper heat insulation cylinder and the middle heat insulation cylinder. Along a height direction of the single crystal growing furnace, a distance between the top of the heater and the bottom of the support ring is an oxygen passing gap. The heater is movable relative to the support ring to adjust the oxygen passing gap.