Advantages of Silicon Carbide

High hardness and wear resistance: The Mohs hardness is 9.5, second only to diamond, making it an ideal wear-resistant material

High thermal conductivity: The thermal conductivity (4.9W/cm · K) is three times that of silicon, with superior heat dissipation performance and suitable for high temperature environments

High breakdown electric field strength (2-4MV/cm): 10 times that of silicon, capable of withstanding higher voltages, suitable for high-voltage devices

Wide bandgap width: 3.2eV, SiC-4H, can withstand temperatures above 600 degrees Celsius, strong radiation resistance

High electronic saturation rate: twice that of silicon, supporting high-frequency operations such as 5G communication and radar systems

Classification and preparation technology of silicon carbide

Silicon carbide can be divided into α - SiC (hexagonal structure) according to its crystal structure, which is commonly used in high-temperature applications such as abrasives and refractory materials, and β - SiC (cubic structure), suitable for semiconductor devices such as power devices and RF chips. According to their conductivity, they can be divided into conductive types, used for power devices such as MOSFETs and diodes, and semi insulating types, used for high-frequency RF devices such as 5G base stations and radars.

The growth technology of silicon carbide single crystals includes the mainstream physical vapor transfer (PVT) method, which sublimates silicon carbide powder at high temperature (>2000 ° C) and drives gas phase transfer to the surface of the seed crystal for recrystallization through temperature gradient; The second method is high-temperature chemical vapor deposition (HTCVD), in which silane and hydrocarbons are introduced into a high-temperature reaction chamber to deposit and grow SiC single crystals on the surface of the seed crystal through gas-phase reaction. This method can improve crystal quality, but the cost is relatively expensive. The third method is the liquid-phase method, in which silicon and carbon are dissolved in a metal solvent, and SiC is slowly cooled at high temperatures to precipitate from the solution and grow a single crystal on the seed crystal. In addition, chemical vapor deposition (CVD) is used for high-quality epitaxial layer growth, supporting complex device structures.

Large size, defect control, and application expansion are the future development directions of the silicon carbide industry

At present, silicon carbide wafers are still mainly 6-inch, and the technological trend is to develop towards 8-inch wafers. How to optimize PVT processes or develop liquid phase methods (LPE) to reduce lattice defects, improve yield, and reduce costs is a key factor in development. In addition, heterogeneous integration with gallium nitride (GaN) and silicon-based devices will efficiently improve system performance (such as hybrid SiC GaN power modules).

In terms of application fields, new energy vehicles are the largest incremental market. If SiC is fully used in the main inverters and on-board chargers (OBC) of new energy vehicles, the range will be improved by at least 10% -15%, the device volume will be reduced by 50%, which is conducive to battery optimization. The popularization of 800V high-voltage platforms requires silicon carbide MOSFETs to support high voltage and low loss. In the field of renewable energy, the high efficiency demand for photovoltaic inverters and wind power converters further promotes the development of the silicon carbide market. In the 5G/6G communication field, semi insulating SiC substrates are used for RF front-end modules (PA, LNA) to adapt to high-frequency millimeter waves. In the aerospace and industrial fields, silicon carbide high-temperature resistant devices replace traditional silicon-based solutions, which can reduce system weight, reduce heat dissipation requirements, and improve device performance.

According to LMC Automotive's prediction, the mass production of 8-inch wafers by 2025 is expected to lead to a penetration rate of over 30% for automotive SiC. With further cost reduction, the global silicon carbide market is expected to exceed 10 billion US dollars by 2030, replacing traditional silicon-based devices in the photovoltaic and energy storage fields. In the long run, silicon carbide SiC, gallium nitride GaN, and gallium oxide Ga2O3 will form a "high voltage high frequency medium low voltage" division of labor, promoting the efficiency revolution of global energy and communication systems. The silicon carbide industry is currently on the brink of explosive growth, and the two-way guidance of technological breakthroughs and policy support is accelerating its transition from high-end options to mainstream choices.

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