On March 2, multiple automotive chip companies saw their share price drop on the New York Stock Exchange. STMicroelectronics and Wolfspeed saw their prices drop 2.43% and 6.98%, receptively. The cause was Tesla, which announced on the prior day that it plans to substantially reduce the number of silicon carbide (SiC) power management ICs it uses to cut costs.
Despite this setback and Tesla’s announcement, demand for SiC chips is only expected to grow going forward as more and more electric vehicles hit the market and more and more charging stations are built. So what is the big deal with SiC chips?
SiC semiconductors gained notice 40 years ago. In the 1980s, SiC was talked up as the material that can overcome the property limits of silicon as it can withstand higher temperatures and higher voltages. Research started in earnest in 1990s as there wasn’t sufficient technology to make single crystal wafers and epitaxy.
Commercialization began in the early 2000s, with more and more companies that manufacture SiC wafers appearing. In 2002 a 2-inch SiC wafer was introduced; in 2011 a 4-inch SiC wafer was launched and in 2016 6-inch SiC wafers, which is currently the mainstream, rolled out.
SiC has three times the band gap of 3.26eV compared to silicon (Si), allowing it to operate at high temperatures. Its thin-film breakdown point is ten times higher than Si, allowing it to operate at ultra-high voltage. In heat conductivity, its is four times superior to Si, meaning it doesn’t require as much power to cool down. For these reasons, SiC semiconductors are in high demand from EVs, aerospace and other advanced industries.
The fast growth of the EV market is currently the main driver of growth of the SiC market. This is because battery systems of EVs are shifting to 800V from 400V. The higher voltage means faster charging times for batteries but also makes it more vulnerable to defects. This is where SiC chips step in.
In EVs, SiC chips are especially in high demand for use in main inverters, which convert the DC from the battery pack to AC to operate the motor. SiC has less switching loss compared to Si. For this reason, Tesla currently uses STMicroelectronics’ SiC power management ICs on its inverter systems.
But the problem is price. A 6-inch SiC wafer currently costs ten times more than an 8-inch Si wafer.
This is why in March Tesla announced that it will lower the use of SiC power management ICs by 75%, while many expect the company to start using cheaper Si insulating gate IGBT on its low-tier car models.
But despite this short setback, demand for SiC power management ICs is expected to only grow in the long term. According to analyst firm TrendForce, the market for the chips is expected to be worth US$2.275 billion this year, a 41.4% growth from 2022. TrendForce expects the market to grow 32.9% on average per year up to 2026, when it is expected to be worth US$5.328 billion.