Doped Polysilocarb Precursors for High-Purity SiC and SiOC
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Solution Overview
Problem
Existing methods for producing silicon carbide and silicon oxycarbide materials are costly, difficult to scale, and fail to achieve high purity levels required for commercial applications, particularly in semiconductor-grade materials, due to contamination and high production costs.
Innovation Solution
Development of polysilocarb materials and processes that produce high purity silicon carbide and silicon oxycarbide compositions through controlled curing and pyrolysis of polysilocarb precursor formulations, allowing for the formation of non-reinforced and composite structures with precise control over impurity levels and molar ratios.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If conventional methods are used to produce silicon carbide and silicon oxycarbide materials, then production costs are high and scaling is difficult, but purity levels remain insufficient for semiconductor-grade applications
Solution Approach 1:
The patent changes the chemical composition parameters of the precursor material by incorporating specific dopants (boron, phosphorus, aluminum) at controlled concentrations during the polysiloxane synthesis stage. This allows direct formation of doped SiC with semiconductor-grade purity (99.99% to 99.9999%) through pyrolysis, eliminating the need for post-processing purification steps and reducing manufacturing complexity while achieving target purity levels.
Solution Approach 2:
The patent performs preliminary doping of the polysiloxane precursor material before pyrolysis, incorporating the desired dopant elements and their precise concentrations into the organic precursor structure. This preliminary action ensures that the dopants are uniformly distributed and properly incorporated into the SiC lattice during conversion, achieving high purity and controlled doping without requiring subsequent complex purification or doping steps.
2Manufacturing precision
If high purity levels are achieved through conventional purification methods, then production costs increase and manufacturing complexity increases, but scalability remains limited
Solution Approach 1:
The patent achieves high purity by changing the synthesis approach from post-purification to pre-control: using high purity starting materials and controlling reaction conditions during polysiloxane formation and pyrolysis to prevent impurity formation. This parameter control approach simplifies the overall process by eliminating multiple purification steps while maintaining 99.99% to 99.9999% purity levels.
Solution Approach 2:
The patent extracts the purification function from the process by preventing impurity formation in the first place through careful selection of high purity precursors and controlled reaction conditions. Rather than adding complex purification steps, the method takes out the need for purification by designing a synthesis pathway that inherently produces high purity material.
3Adaptability or versatility
If dopants are added to achieve desired electrical properties, then material functionality improves, but purity levels may be compromised
Solution Approach 1:
The patent simultaneously achieves high purity and controlled doping by changing the concentration parameters of dopant addition during precursor synthesis. By adding dopants at precisely controlled low concentrations (parts per million to parts per thousand range) during the polysiloxane formation stage, the method ensures uniform distribution and proper incorporation into SiC lattice while maintaining overall material purity above 99.99%, enabling control of electrical properties without compromising purity.
Solution Approach 2:
The patent applies local quality by introducing dopant elements at specific locations in the material structure during precursor formation, ensuring dopants are incorporated into the polymer chains before pyrolysis. This localized incorporation during synthesis ensures uniform distribution throughout the final SiC material, achieving desired electrical properties (n-type or p-type conductivity) while maintaining high overall purity.
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
Achieves high purity silicon carbide and silicon oxycarbide materials with purity levels of at least 99.99% and 99.9999%, suitable for semiconductor applications and other high-performance uses, while reducing production costs and environmental impact.
Implementation Method 1
The liquid precursor is cured to a solid or semi-solid material
Implementation Method 2
The cured material is pyrolized to a ceramic material
Data Source
AI summary
Organosilicon chemistry, polymer derived ceramic materials, and methods. Such materials and methods for making polysilocarb (SiOC) and Silicon Carbide (SiC) materials having 3-nines, 4-nines, 6-nines and greater purity. Processes and articles utilizing such high purity SiOC and SiC.