SiC Production Reactor with Resistive Heating
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Solution Overview
Problem
The current methods for producing silicon carbide (SiC) wafers are costly and result in low-purity materials due to impurities, leading to crystal defects and high manufacturing costs, which are not suitable for large-scale industrial production and high-purity requirements, especially for power electronics and electromobility applications.
Innovation Solution
A SiC production reactor system that uses a process chamber with multiple SiC growth substrates heated by metal electrodes, a gas inlet unit for controlled feed gas supply, and a control unit to manage temperature and deposition rate, enabling the production of high-purity SiC material with a deposition rate of over 200 μm/h, which is then deposited as SiC on the substrates.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If acid leaching is used to purify SiC particles, then purity is improved to 99.99% or 99.999%, but particle size must be reduced to 200-300 microns which increases surface area for contamination
Solution Approach 1:
The patent applies preliminary action by performing acid leaching treatment before the actual PVT growth process. The SiC particles are pre-purified to remove trace metals, then used as source material for crystal growth. This preliminary purification step ensures that the source material has high purity (99.99% or higher) before being used in the growth process, preventing contamination during subsequent handling and processing steps.
2Productivity
If powder SiC material is used as source material, then sublimation rate is increased, but crystal defects increase due to impurities
Solution Approach 1:
The patent applies parameter changes by carefully controlling the particle size distribution and purity level of the SiC source material. By optimizing these parameters - using particles in the 200-300 micron size range with purity of 99.99% or higher - the patent achieves both adequate sublimation rate and high crystal quality, preventing the formation of parasitic polycrystalline depositions and maintaining monocrystalline growth.
Solution Approach 2:
The patent converts the potential harm of high surface area in powdered material into a benefit by using controlled powder morphology. The powdered SiC particles provide sufficient surface area for effective sublimation while the acid leaching process removes contaminants that would otherwise cause defects. This transformation allows the material to exhibit both high reactivity and high purity simultaneously.
3Ease of manufacture
If trace metals are present in source material, then manufacturing cost is reduced, but crystal defects increase leading to lower yield
Solution Approach 1:
The patent applies preliminary action by implementing acid leaching treatment before the PVT growth process. The SiC particles are pre-purified to remove trace metals, then used as source material for crystal growth. This preliminary purification step ensures that the source material has high purity (99.99% or higher) before being used in the growth process, preventing contamination during subsequent handling and processing steps.
Solution Approach 2:
The patent uses acid leaching as an intermediary process between SiC production and PVT growth. This intermediary step selectively removes trace metal impurities from the SiC particles while leaving the desired SiC material intact. The acid treatment acts as a mediator that purifies the source material, ensuring high crystal quality and yield in the subsequent growth process.
4Productivity
If high deposition rate is achieved, then productivity is improved, but purity may be compromised due to rapid deposition
Solution Approach 1:
The patent applies parameter changes by optimizing the deposition conditions including temperature, pressure, and gas flow rates. By carefully controlling these parameters, the patent achieves high deposition rates while maintaining high purity. The optimized parameters ensure that SiC deposits cleanly on the substrate without incorporating impurities, even at rapid deposition speeds.
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 allows for the efficient and cost-effective production of high-purity SiC material, reducing crystal defects and manufacturing costs, enabling the production of high-quality SiC wafers suitable for large-scale industrial use and advanced applications.
Implementation Method 1
each SiC growth substrate is coupled between at least one first metal electrode and at least one second metal electrode for heating the outer surface of the SiC growth substrates or the surface of the deposited SiC to temperatures between 1300° C. and 1800° C., in particular by means of resistive heating
Implementation Method 2
a gas inlet unit for feeding one feed-medium or multiple feed-mediums into a reaction space of the process chamber for generating a source medium... for depositing SiC
Data Source
AI summary
The present invention relates to a method for producing a preferably elongated SiC solid, in particular of polytype 3C. The method according to the invention preferably includes at least the following steps: Introducing at least a first source gas into a process chamber, said first source gas including Si, introducing at least one second source gas into the process chamber, the second source gas including C, electrically energizing at least one separator element disposed in the process chamber to heat the separator element, setting a deposition rate of more than 200 μm/h, where a pressure in the process chamber of more than 1 bar is generated by the introduction of the first source gas and/or the second source gas, and where the surface of the deposition element is heated to a temperature in the range between 1300° C. and 1800° C.