Silicon carbide, or SiC, is an exceedingly rare, naturally occurring compound found in small quantities via the mineral moissanite present in meteors. While SiC might not be easy to locate in nature, this incredible compound has found a significant footing in the world of electronics as a highly-functional and desirable material for building semiconductors.
But what makes SiC – a compound that has seen use in electronic components like LEDs in the early 1900s – an ideal candidate for many modern semiconductor designs?
From rare mineral to high-performing semiconductor
To understand why silicon carbide is becoming increasingly popular in semiconductor design, it can help to first review some of its history as a material and its physical characteristics. While SiC is indeed very rare in nature, wide-scale production of Silicon Carbide is first credited to American chemist Edward Goodrich Acheson in the 1890s when his attempt to synthesize diamonds led to the creation of SiC. A few years later, it was found naturally occurring by Ferdinand Henri Moissan in the Canyon Diablo meteorite in Arizona -- leading to the mineral name moissanite.
SiC is an exceptionally hard material with a very symmetrical atomic structure. Its ability to withstand high voltages made it a popular choice in early lightning arresters. It also has low thermal expansion, high thermal shock resistance, and very high thermal conductivity, making it a popular choice in automotive applications such as brakes.
Harness SiC’s potential
For years, SiC was seen as a material with high potential for use in semiconductor design. However, in comparison to traditional Silicon, SiC had a much higher instance of deformities and intrinsic defects resulting from the manufacturing process. It was very difficult to create SiC semiconductors with the necessary precision required for electronics design. Thanks to recent advancements in manufacturing processes, this has changed, and we are now beginning to truly realize the vast potential of SiC.
Silicon Carbide has the fortunate distinction of being quite compatible with the fabrication processes used for Complementary Metal Oxide Semiconductors (CMOS). This means that modern manufacturers can utilize the same processes for much of the production of SiC wafers as they do for other Silicon wafers. SiC, however, does require a much higher temperature processing step compared to traditional silicon. But with the correct ovens or furnaces, relatively high-yield wafers can be obtained.
Another key to tapping into the vast potential of SiC technology is working with the right partners. While many companies are venturing into creating components using SiC, companies like Wolfspeed are unique in having years of experience working with this material. Combined with that experience is a commitment to continuing to innovate new ways to use this powerful tech.
SiC’s growing list of applications
Today, SiC’s unique characteristics have made it a popular choice for many modern designs -- and one of those growing fields is in the realm of automotive technologies. One of the primary reasons for this growth is SiC’s temperature performance. Today’s automotive designs -- particularly in the booming electrically-powered automotive industry -- require massive amounts of current. With the significant amount of power it takes to accelerate a vehicle comes massive amounts of heat. SiC is uniquely capable of not only withstanding rapid changes in temperature (say from a car parked outside in January that then quickly starts and accelerates on the highway), but also has incredible load tolerance, leading to less power loss through heat dissipation.
Another key benefit of SiC versus traditional Silicon is its contributions towards meeting emissions and fuel consumption standards. One of the most significant factors to maximize fuel efficiency is by keeping vehicle weight down. Compared to silicon semiconductor devices, the electrical field strength of SiC is nearly ten times higher. This allows for higher power density of comparable components as well as reduced system size and therefore weight.
Supporting the booming Internet of Things
An additional area where SiC has seen a recent increase in use is in the field of Radio Frequency (RF) communication. As the Internet of Things has continued to grow, reliable and fast communication has become increasingly important. One of the most popular communication standards for the IoT has quickly become RF due to its reliability, low cost-to-performance ratio, and ease of use. RF, however, requires significant power consumption particularly when transmitting over long distances. This power results in correspondingly high temperatures -- again, making SiC an excellent choice.
Another space that the Internet of Things is influencing the use of SiC semiconductors is in the Industrial IoT. These industrial applications often take place in very harsh environments with high temperatures -- such as mines, oil refining operations, and pump facilities. Access to these facilities can be dangerous and difficult, meaning reliability and performance -- particularly in the face of high temperature -- is of utmost importance. With that being the case, SiC is quickly becoming the gold standard where the combination of high temperature performance and reliability are of concern.
One of the most promising applications of SiC technology is in SiC-on-Si substrates. In this use, semiconductor designs can reap many of the benefits of SiC -- high temperature performance and thermal conductivity, load tolerance, and high frequency switching -- while also enjoying the large-scale availability and low cost of traditional silicon. In many ways, it’s the best of both worlds.
With the growth in high performance semiconductor applications, driven by the boom in electric vehicles, the Internet of Things, and even Artificial Intelligence, SiC has seen a recent and significant growth in use. As systems become increasingly demanding and power solutions require incredible robustness, look for SiC to become even more of a mainstay in the world of electronic components -- and if you’re searching for a way to increase your design’s performance, giving SiC a look is a great place to start.
