Silicon Carbide: The Bright Star of Third Generation Semiconductor Materials

1,Definition and structure of silicon carbide
Silicon carbide, in terms of its chemical composition, is a compound made of two elements, silicon (Si) and carbon (C), bonded covalently. Its crystal structure is rich and varied, and the common ones are cubic crystal system (β-SiC) and hexagonal crystal system (α-SiC). Different crystal structures give silicon carbide different performance characteristics, with α-SiC being more common in industrial applications due to its higher thermal and chemical stability. At the atomic level, silicon and carbon atoms are precisely aligned to form a strong and organized lattice structure, which lays a solid foundation for the unique properties of silicon carbide.

2,Characteristics of Silicon Carbide
(1) High bandwidth: Silicon carbide has a bandwidth of up to 3.2eV, about three times that of conventional silicon materials. This feature allows silicon carbide devices to operate stably at higher temperatures, higher voltages and with lower leakage currents, which significantly improves device performance and reliability. For example, at high temperatures, silicon devices may experience a dramatic increase in carrier concentration due to thermal excitation, which can lead to device failure, whereas silicon carbide devices are able to maintain stable operation due to its high bandwidth, which effectively protects against such thermal disturbances.
(2) High thermal conductivity: Silicon carbide has a very high thermal conductivity, which is 3-5 times higher than that of silicon. Good thermal conductivity means that silicon carbide is able to conduct heat more efficiently and quickly dissipate the heat generated during the operation of electronic devices, effectively lowering the device temperature and improving heat dissipation efficiency. Taking power semiconductor devices as an example, when running at high power, a large amount of heat will cause the device performance to drop or even damage it. Devices made with silicon carbide materials, however, are able to run stably and consistently at higher power due to its excellent heat dissipation ability, greatly improving the performance and service life of the devices.
(3) High breakdown field strength: The breakdown field strength of silicon carbide is about 10 times that of silicon, which enables it to withstand higher voltages. In power electronics, the high breakdown field strength means that power devices can be manufactured with higher withstand voltages and in smaller sizes. For example, in high-voltage transmission and power conversion systems, the use of silicon carbide devices can effectively reduce the number of devices and system size, while improving the conversion efficiency and stability of the system.
(4) high hardness and wear resistance: silicon carbide is extremely hard, Mohs hardness of 9.5, second only to diamond. This high hardness characteristic makes it widely used in the field of wear-resistant materials, such as making abrasives, cutting tools, wear-resistant linings and so on. In industrial production, many equipments need to run in the harsh wear environment, such as mining machinery in the crusher, mill, the use of silicon carbide material parts can significantly improve the wear resistance of the equipment, reduce the cost of maintenance of the equipment, and extend the service life of the equipment.
(5) Chemical stability: silicon carbide has good chemical stability, at room temperature almost does not react with any chemical reagents, even at high temperatures, strong acids and alkalis and other extreme environments, its chemical properties are relatively stable. This characteristic makes silicon carbide in the chemical industry, metallurgy and other corrosive environments have important application value, for example, can be used in the manufacture of corrosion-resistant pipeline, reactor lining and so on.

3, the application of silicon carbide
(1) new energy vehicles: in the field of new energy vehicles, silicon carbide is playing an increasingly important role. On the one hand, the use of silicon carbide power modules in motor drive systems can significantly improve system efficiency and reduce energy loss, thereby increasing the vehicle's range. For example, the Tesla Model 3 uses silicon carbide power modules, which have led to significant improvements in energy efficiency and performance. On the other hand, in on-board charging and DC/DC conversion, the application of silicon carbide devices can realize higher power density and faster charging speed, thus improving the charging experience of users. With the rapid development of the new energy vehicle market, the demand for silicon carbide in this field will continue to grow.
(2) 5G communication: 5G communication network puts forward higher requirements on the performance of RF devices. Due to its high electron mobility, high breakdown field strength and other characteristics, silicon carbide-based RF devices are able to achieve higher power output and more efficient signal processing to meet the demand for high-power, high-efficiency RF devices in 5G base stations. At the same time, the miniaturization and lightweight characteristics of silicon carbide devices also help reduce the volume and weight of base station equipment, improve the integration and reliability of equipment, and promote the widespread application and development of 5G communication technology.
(3) Photovoltaic and energy storage: In the photovoltaic industry, the inverter is the key equipment for converting solar energy into electricity. The application of silicon carbide power devices can effectively improve the conversion efficiency of the inverter and reduce its energy loss in the working process, thus improving the overall performance and economic benefits of the photovoltaic power generation system. In the field of energy storage, silicon carbide devices can be used in battery management systems and power conversion systems, which can realize fast charging and discharging, improve the stability and reliability of the energy storage system, and promote the development and application of energy storage technology.
(4) Aerospace: The aerospace field is extremely demanding on the performance of materials, requiring materials with high reliability, high temperature resistance, radiation resistance and other characteristics. Silicon carbide has been widely used in the aerospace field by virtue of its excellent comprehensive performance. For example, silicon carbide materials and devices can play an important role in the hot-end components of aviation engines, the heat dissipation systems of electronic equipment in aircraft and the power systems of satellites, helping to improve the performance and reliability of aerospace equipment, reduce the weight of equipment, and enhance the efficiency of energy utilization.
(5) industrial and electric power: in the industrial field, silicon carbide can be used to manufacture a variety of wear-resistant, high temperature, corrosion-resistant parts, such as mechanical seals, high-temperature furnace lining, wear-resistant piping, etc., to improve the service life of industrial equipment and operational efficiency. In the field of electric power, silicon carbide power devices can be used in the transmission, transformation and distribution of smart grid, to realize efficient conversion and transmission of electric energy, improve the stability and reliability of the power grid, and reduce transmission losses.
4, the development trend of silicon carbide
(1) technological innovation to promote performance: with the continuous development of materials science and semiconductor technology, silicon carbide preparation process and device manufacturing technology will continue to innovate. In the future, through the optimization of crystal growth process, improve epitaxial technology and device design, is expected to further improve the quality and performance of silicon carbide materials, reduce defect density, improve device integration and reliability, expanding the application of silicon carbide in more high-end fields.
(2) Cost reduction to promote market penetration: At present, the relatively high cost of silicon carbide materials and devices, limiting its large-scale application. In the future, with the expansion of the production scale, the maturity of the technology and the improvement of the industrial chain, the production cost of silicon carbide is expected to gradually reduce. On the one hand, the enterprise through the expansion of production capacity to achieve economies of scale, reduce the production cost per unit of product; on the other hand, technological innovation will improve production efficiency, reduce the consumption of raw materials and scrap rate, and further reduce costs. Reduced costs will make silicon carbide in more areas with economic feasibility, to promote its market penetration and application expansion.
(3) Application areas continue to expand: with the improvement of silicon carbide performance and cost reduction, its application areas will continue to expand. In addition to the existing new energy vehicles, 5G communications, photovoltaic energy storage and other areas of in-depth application, silicon carbide will also be in the emerging areas such as quantum computing, artificial intelligence hardware acceleration, solid-state LiDAR and other aspects of the application of huge potential. At the same time, as the global concern for energy efficiency and environmental protection continues to grow, silicon carbide, as a highly efficient and energy-saving material, will play a more important role in the energy sector, contributing to the global energy transition and sustainable development.
(4) Accelerated development of industrial synergy: the development of the silicon carbide industry can not be separated from the industry chain of upstream and downstream enterprises. In the future, enterprises in substrate, epitaxial, device manufacturing, application development and other links will strengthen cooperation and communication to form a closer industrial ecology. Through joint technical research and development, development of industry standards, optimization of supply chain management, etc., to improve the overall competitiveness of the industry and promote the rapid and healthy development of the silicon carbide industry.
In conclusion, as a representative of the third generation of semiconductor materials, silicon carbide is becoming a global research hotspot in the field of materials science and semiconductors and the focus of industrial development by virtue of its excellent performance and broad application prospects. With the continuous progress of technology and the gradual maturation of the industry, silicon carbide is expected to realize breakthroughs in more fields and make important contributions to the promotion of modern scientific and technological progress and social development.