SiC Technology Powers the Shift to an All-Electric Future

Article By : Majeed Ahmad

Silicon carbide wafer capacity is growing as the next generation of power semiconductor designs emerge from car makers.

Wolfspeed, formerly Cree, kicked off its rebranding with a major design win: A supply chain agreement with GM to develop and produce silicon carbide (SiC) semiconductors for the automaker’s EVs. In August, Wolfspeed expanded its multi-year agreement with STMicroelectronics with an $800 million deal to supply 150-mm bare and epitaxial SiC wafers.

Both transactions highlight the crucial role of SiC technology in the auto industry’s transition to an all-electric future. According to Claire Trodec, director of Power & Wireless Division at Yole Development, SiC-based power semiconductors could save automakers up to $750 in battery costs per EV unit.

Cree, which earlier sold its LED business, is now betting on SiC power semiconductors after adopting the name of its Wolfspeed division. “That’s who we are,” said company CEO Gregg Lowe, asserting that SiC technology will drive the next generation of power semiconductors.

Wolfspeed, Durham, N.C., will produce SiC power semiconductors at its 200-mm fab in Marcy, N.Y., beginning in early 2022. The Mohawk Valley Fab will be the world’s largest SiC production line, a $1 billion investment.

While the global chip shortage makes headlines, Wolfspeed has been ramping SiC capacity for several years.

STMicroelectronics also anticipated IC supply chain disruptions. Before the chip shortage, it signed long-term SiC wafer deals to help fill the supply and demand gap. Besides the SiC wafer supply agreement with Wolfspeed, the Franco-Italian chipmaker inked a similar deal with wafer manufacturer SiCrystal, a ROHM company based in Nürnberg, Germany. In 2019, STmicroelectronics acquired Swedish SiC wafer manufacturer Norstel to kickstart R&D on 200-mm wafers.

Meanwhile, other SiC players have also been pursuing wafer supply agreements in anticipation of future demand for SiC devices in EV designs. For instance, after an unsuccessful attempt to acquire Cree’s Wolfspeed operation in 2017, Infineon signed a multi-year agreement with Cree to supply SiC wafers. The German chipmaker also approached the Japanese wafer manufacturer Showa Denko K.K. for access to its SiC material and epitaxy technology.

At that time, Infineon projected that SiC semiconductors would grow as much as 40 percent annually over the next five years. Indeed, it was the widespread adoption of SiC semiconductors in electric propulsion systems across the voltage spectrum of 400 V to 800 V and beyond that propelled major SiC players.

In retrospect, it was a blessing in disguise.

Little did suppliers know that a far bigger capacity crunch was at hand. Moral of the story? As former Intel CEO Andrew Grove declared, “Only the paranoid survive.”

The Tesla Model 3 inverter consists of 24 power modules, each module incorporating two SiC MOSFETs.

Take STMicroelectronics’ supply relationship with Tesla, the EV maker that pioneered SiC components in its Model 3 launched in 2018. According to industry reports, STMicroelectronics was the supplier of SiC semiconductors used in the power module that served as the Model 3’s traction motor. A teardown report from System Plus Consulting revealed that the power module contained SiC MOSFETs from ST.

Fast forward to 2021, as chip shortages severely disrupt automakers’ supply chains, the SiC supply deal with Tesla appears to be stable.

In the final analysis, EV power designs and SiC semiconductors work well together. Besides traction inverters, SiC components are being used for onboard chargers and DC/DC converters. For instance, STMicroelectronics has partnered with the Renault-Nissan-Mitsubishi Alliance and Chinese EV maker BYD to supply SiC components for onboard chargers.

This article was originally published on EDN.

Majeed Ahmad, Editor-in-Chief at Electronic Design News (EDN), has covered electronics design industry for more than two decades. He holds Masters’ degree in telecommunication engineering from Eindhoven University of Technology. He has worked in various editorial positions, including assignments for EE Times Asia and Electronic Products.


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