Semiconductors made of silicon carbide (SiC) process electricity more efficiently than traditional semiconductors in some important applications. Therefore the new technology is of particular interest for electric car manufacturers: thanks to SiC semiconductors, improved battery control helps save energy—greatly increasing the range of electric cars. SiC-based semiconductors also enable faster recharging. Today there are already alot of semiconductors in every electric vehicle. In future especially the SiC variant could be on the rise with their advantages of switching speed, heat loss and compact size. Other companies such as mobile network providers, smartphone manufacturers and the automation industry also have high hopes for these tiny chips.
Advantages and Applications of SiC Semiconductors
is how much smaller SiC power electronics semiconductors can be manufactured than traditional silicon semiconductors. This is possible because they have a larger band width, enabling them to convert electricity with less heat loss. A silicon semiconductor would have to be significantly larger to achieve the same performance.
Up to 50 percent less
heat loss occurs in SiC semiconductors as compared to conventional semiconductors made of silicon. Thus an important field of application for SiC semiconductors is power electronics, the conversion of electricity into a usable form for a device. For a laptop, for instance, up until now silicon semiconductors have primarily been used for this, but they emit a lot of energy as heat. With silicon-carbide semiconductors, there would be much less heat loss and more energy would be available for charging.
A 300–500 percent
increase in switching frequency can also be achieved by SiC transistors as compared to silicon transistors. This is yet another reason that SiC semiconductors can be used to build significantly smaller-sized components.
A 10 to 15 percent
greater range for electric vehicles can be achieved by SiC semiconductors because they convert energy more efficiently. As a result, car manufacturers can install smaller batteries in their electric vehicles. This is a win-win for the manufacturers and could provide a boost to the industry.
For modern 5G technology
SiC semiconductors are also ideal. The ultra-fast network will demand a lot of power and performance especially from the infrastructure components like transmitting stations. But also to recharge smartphones faster, manufacturers might use SiC semiconductors in the future. In addition, the new semiconductors are also ideally suited for wireless chargers and data center servers.
A world of new possibilities
is opened up by SiC semiconductors for digitizing industrial processes. As an example, processes that require especially high speed for power electronics can be better supported, for instance with faster sensor systems. The use of 5G-controlled mobile devices based on SiC semiconductors also offers great potential for further optimization of Industry 4.0.
$412 billion dollars
was the entire semiconductor industry’s turnover last year. SiC semiconductors are still a small niche product, with around $500 million USD in sales. However, industry experts expect rapid sales growth—of 10 to 25 percent annually between 2020 and 2022 and even more than 40 percent as of 2023 due to electric vehicles.
Basically, all semiconductors are made from crystals, which are created from a powder, for instance of silicon or silicon carbide, at very high temperatures. The crystals are subsequently cut into slices, known as wafers. Very complex electronic circuits can be deposited onto the wafers, which ultimately make up the microelectronic device.
Since both the growing of the crystals and the manufacture of the necessary powder take place at incredibly high temperatures and under ultra-pure conditions, the furnaces must be made of extremely robust components. SGL Carbon is a global leader in this field with its highly pure, heat- and corrosion-resistant graphite components that are used in both the production of SiC powders and for growing SiC crystals. Examples of these include heat shield tubing, graphite crucibles and graphite heaters, not to mention special graphite felts for thermal insulation.
Production of the New Semiconductor Material
Over 50 years
of research has gone into the production of silicon-carbide semiconductors and the growth of silicon-carbide crystals, which are produced mainly using the physical-vapor transport (PVT) process. A small silicon carbide crystal is manufactured at high temperature and low pressure. The particles make their way through a carrying gas to the cooler seed crystal, where crystallization takes place due to supersaturation.
2,400 degrees Celsius
is required for this process. The graphite components that SGL Carbon supplies for the furnaces must be highly pure so that the crystals are not rendered useless by the smallest impurities. In contrast, temperatures of only around 1,500 degrees are required for regular silicon crystals.
10 to 14 days
is how long it takes to grow a silicon carbide crystal in the furnace. This, along with the significantly higher energy consumption, is one of the reasons that they are more expensive than regular silicon crystals, which can be grown in just two days.
is the size of the lastest wafers of silicon carbide already. Very soon, SiC wafers with a 200 mm diameter will be produced on an industrial scale. At this point they will have reached a size that is a standard in the “traditional” silicon-based industry and will thereby enable the breakthrough for SiC-based electronics.