The Past and Present of Silicon Carbide (SiC)

First generation elemental semiconductor materials: such as silicon (Si) and germanium (Ge);

Third generation wide bandgap materials: such as silicon carbide (SiC), gallium nitride (GaN), aluminum nitride (ALN), gallium oxide (Ga2O3), etc.

Among them, silicon carbide and gallium nitride are currently the most promising semiconductor materials in terms of commercial prospects, and can be regarded as the new generation of "golden race track" in the semiconductor industry.

The first discovery of silicon carbide in history was in 1891, when American Acheson discovered a carbon compound when he dissolved diamonds. This was the first synthesis and discovery of silicon carbide. After a century of exploration, especially since entering the 21st century, humanity has finally clarified the advantages and characteristics of silicon carbide, and utilized its properties to create various new devices, leading to rapid development of the silicon carbide industry.

※ Performance advantages of silicon carbide

If we only consider silicon carbide chips, compared to traditional silicon-based power chips, silicon carbide has unparalleled advantages in power semiconductors: it can withstand larger currents and voltages, higher switching speeds, smaller energy losses, and higher temperature resistance. Therefore, power modules made of silicon carbide can correspondingly reduce the components of capacitors, inductors, coils, and heat dissipation components, making the entire power device module lighter, more energy-efficient, and with stronger output power, while also enhancing reliability. The advantages are very obvious, and the specific summary is as follows:

1. Lower impedance leads to smaller product designs and higher efficiency;

3. Excellent high-temperature characteristics, capable of working at higher temperatures.

Why is silicon carbide so expensive?

Everyone knows about the huge commercial prospects of silicon carbide in the future, but those who enter this industry will encounter the first and most practical problem, what about the materials?

At present, the extremely mature commercial environment of the traditional silicon-based industry is at least partly due to the relatively easy availability of silicon materials. The mature and efficient preparation technology of silicon materials makes them currently very affordable. Currently, 6-inch silicon polishing wafers are only 150 yuan, 8-inch wafers are 300 yuan, and 12 inch wafers are around 850 yuan.

Only when the raw materials are cheap enough can the industry scale grow!

Currently, using the direct pull method, silicon single crystal rods of about 2-3 meters can be grown in 72 hours, and one single crystal rod can cut thousands of silicon wafers at once.

Do you know how thick a silicon carbide single crystal can grow in 72 hours? It's less than a few centimeters!!!

The fastest method for growing silicon carbide single crystals currently has a growth rate of around 0.1mm/h-0.2mm/h, resulting in only crystals with a thickness of 7.2mm-14.4mm after 72 hours.

So you can imagine how expensive the produced silicon carbide single crystal wafers could be. At present, the selling price of 4-inch silicon carbide substrates is around 2000-3000 yuan, and 6-inch substrates reach the level of 6000-8000 yuan. The price of epitaxial wafers is at least higher than X2, and they are still out of stock.

As the world's leading silicon carbide enterprise, Cree in the United States almost monopolizes more than 70% of its production capacity. Therefore, downstream manufacturers at home and abroad have signed long-term contracts with Cree to lock in production capacity.

The market for silicon carbide

Silicon carbide MOSFETs and silicon carbide diodes are used in applications such as solar energy, UPS, industrial, automotive, etc. They are mainly concentrated in inverters for photovoltaic energy storage, UPS power supplies for data center servers, smart grid charging stations, and other fields that require high conversion efficiency. However, with the development of electric and hybrid vehicles (xEV) in recent years, SiC has also rapidly emerged in this new field, radiating industries including energy (PV, EV charging, smart grid, etc.), automobiles (OBC, inverters), infrastructure (servers), etc.

Overall, in the near future, we can anticipate that silicon carbide will have a revolutionary impact on the power electronics industry!