Quartz Glass Crucible Crystallization-Accelerator Coating for Czochralski Stability
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Solution Overview
Problem
Existing quartz glass crucibles used in the Czochralski method for silicon single crystal production face issues with crucible deformation and crystal layer delamination during long-term use, leading to reduced crystal quality and yield due to insufficient crystal layer thickness and random crystal growth.
Innovation Solution
A quartz glass crucible with a crystallization-accelerator-enriched coating film is applied to the surface, forming a dome-shaped or columnar crystal layer that maintains stability and prevents delamination, using a binary glass with a low melting point to relieve stress and ensure continuous crystal growth.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If a quartz glass crucible is used for long-term silicon single crystal pulling, then the yield of single crystals can be increased, but the crucible deforms due to viscosity reduction at high temperature
Solution Approach 1:
The patent changes the physical-chemical parameters of the crucible surface by forming a crystal layer with specific composition (SiO2 content of 70-90 wt%) and structure (amorphous to crystalline transition). This parameter change increases surface viscosity and maintains crucible shape stability during long-term use at high temperature
Solution Approach 2:
The patent creates a composite structure consisting of the quartz glass crucible body and a surface crystal layer. This composite material structure combines the high temperature resistance of quartz glass with the viscosity stability of the crystal layer, preventing crucible deformation while maintaining productivity
2Strength
If the inner surface of the crucible is crystallized to increase strength, then heat resistance is improved, but the crystal layer may delaminate and cause dislocation
Solution Approach 1:
The patent applies local quality by creating a crystal layer with specific composition (SiO2: 70-90 wt%, Al2O3: 0.1-10 wt%, other oxides: 0-5 wt%) only on the inner surface of the crucible. This localized treatment provides enhanced strength where needed while maintaining good adhesion through controlled crystallization that prevents delamination
Solution Approach 2:
The patent controls the crystallization parameters including SiO2 content (70-90 wt%), Al2O3 content (0.1-10 wt%), and crystallinity (30-100%) to optimize both strength and adhesion. By adjusting these parameters, the crystal layer achieves sufficient strength while maintaining reliable bonding to the crucible body
3Stability of the object's composition
If a thick crystal layer is formed to prevent deformation, then crucible stability is improved, but random crystal growth causes delamination
Solution Approach 1:
The patent controls the crystallization parameters including SiO2 content (70-90 wt%), Al2O3 content (0.1-10 wt%), and crystallinity (30-100%) to promote uniform crystal growth. These parameter controls prevent random crystallization patterns that lead to delamination while maintaining crucible stability
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 solution enhances the crucible's ability to withstand long-term use, prevents dislocation in silicon single crystals, and increases the yield of high-quality silicon single crystals by maintaining a stable crystal layer thickness and structure.
Implementation Method 1
a crystallization-accelerator-enriched coating film which causes a crystallization-accelerator-enriched layer to be formed in the vicinity of the surface of the crucible body by heating during a step of pulling up the silicon single crystal
Implementation Method 2
by heating during a step of pulling up the silicon single crystal
Implementation Method 3
causes a crystallization-accelerator-enriched layer to be formed in the vicinity of the surface
Data Source
AI summary
In an exemplary embodiment, a quartz glass crucible 1 includes: a cylindrical crucible body 10 which has a bottom and is made of quartz glass; and crystallization-accelerator-containing coating films 13A and 13B which are formed on surfaces of the crucible body 10 so as to cause crystallization-accelerator-enriched layers to be formed in the vicinity of the surfaces of the crucible body 10 by heating during a step of pulling up a silicon single crystal by a Czochralski method. The quartz glass crucible is capable of withstanding a single crystal pull-up step undertaken for a very long period of time, such as multi-pulling, and a manufacturing method thereof.