Advantages of TaC Coating in SiC Single Crystal Growth

Currently, silicon carbide dominates the third generation of semiconductors. In the cost structure of silicon carbide devices, substrates account for 47%, and epitaxy contributes 23%. Together, these two components represent about 70% of the overall manufacturing cost, making them crucial in the silicon carbide device production chain. Consequently, improving the yield rate of silicon carbide single crystals—and thereby reducing the cost of substrates—has become one of the most critical challenges in SiC device production.

To prepare high-quality, high-yield silicon carbide substrates, there is a need for better thermal field materials to accurately control production temperatures. The thermal field crucible kit currently in use primarily consists of a high-purity graphite structure, which is employed to heat molten carbon and silicon powders while maintaining temperature. While graphite materials exhibit high specific strength and modulus, excellent thermal shock resistance, and good corrosion resistance, they also have notable disadvantages: they are prone to oxidation in high-temperature oxygen environments, cannot withstand ammonia well, and have poor scratch resistance. These limitations hinder the growth of silicon carbide single crystals and the production of silicon carbide epitaxial wafers, restricting the development and practical applications of graphite materials. As a result, high-temperature coatings like tantalum carbide are gaining traction.

Advantages of Tantalum Carbide Coated Components

Utilizing tantalum carbide (TaC) coatings can address issues related to crystal edge defects and enhance the quality of crystal growth. This approach aligns with the core technical objective of "growing faster, thicker, and longer." Industry research indicates that Tantalum Carbide Coated Graphite Crucibles can achieve more uniform heating, providing excellent process control for SiC single crystal growth and significantly reducing the likelihood of polycrystalline formation at the edges of SiC crystals. Additionally, Tantalum Carbide Coating offers two major benefits:

1.Reducing SiC Defects

There are typically three key strategies for controlling defects in SiC single crystals. Besides optimizing growth parameters and using high-quality source materials (such as SiC source powder), switching to Tantalum Carbide Coated Graphite Crucibles can also promote better crystal quality.

2.Improving the Life of Graphite Crucibles

The cost of SiC crystals has remained high; graphite consumables account for approximately 30% of this cost. Increasing the service life of graphite components is critical for cost reduction. Data from a British research team suggest that Tantalum Carbide Coatings can extend the service life of graphite components by 30-50%. Based on this information, simply replacing traditional graphite with tantalum carbide-coated graphite could reduce the cost of SiC crystals by 9%-15%.

Semicorex offers high-quality Tantalum Carbide coated crucibles, susceptors, and other customized parts. If you have any inquiries or need additional details, please don't hesitate to get in touch with us.

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