SiC and GaN: A Tale of Two Semiconductors

Over the last several decades, advances in silicon carbide and gallium nitride technologies has been characterized by development, growing industry acceptance and the promise of billion-dollar revenues.

The first commercial SiC device arrived in 2001 in the form of a Schottky diode from Germany’s Infineon. Rapid development has followed, and the industry sector is now poised to exceed $4 billion by 2026.

GaN first wowed the industry in 2010 when US-based EPC delivered its super-fast switching transistors. Market adoption hasn’t yet matched that of SiC, but come 2026, power GaN revenues could hit $1 billion.

The secret of future market success for each technology rests with electric and hybrid electric vehicles. For SiC, the EV/HEV market is truly the sweet-spot, at least 60 percent of the more than $ 2.5 billion market is expected to come from this sector.

Tesla kickstarted the SiC power device market in 2017 when it became the first automaker to add SiC MOSFETs to its Model 3. Sourced from STMicroelectronics, the device was integrated with an in-house main inverter design. Other automakers have been quick to follow, including Hyundai, BYD, Nio, General Motors and others.

China’s Geely Automobile recently announced it is collaborating with ROHM Japan on SiC-based traction inverters for its EVs. NIO, China’s answer to Tesla, will implement an SiC-based electric drive system in its vehicles. At the same time, automaker and semiconductor manufacturer BYD has been developing SiC modules for its entire line of EVs.

Last year, China-based electric bus manufacturer Yutong revealed it will use SiC power modules manufactured by StarPower China in bus powertrains. The modules use SiC devices from Wolfspeed.

Hyundai will integrate Infineon’s SiC-based power module for 800-V battery platforms into EVs. In Japan, Toyota is using SiC booster power modules from Denso in its Mirai fuel cell EVs. Meanwhile, GM has just signed up Wolfspeed to supply SiC for its EV power electronics.

European car manufacturers have been slower to embrace SiC, but change is afoot. In June, Renault and STMicroelectronics joined forces to develop SiC and GaN devices for EVs and HEVs. More announcements are expected soon from Daimler, Audi and Volkswagen.

Importantly for Wolfspeed, Infineon, STMicroelectronics, ROHM and Onsemi, automotive OEMs also prefer to buy wafers and devices from multiple sources to ensure reliable supply. Factor in the vast sums of money that China and others are pouring into the SiC supply chain, and volume sales will only continue to rise.

Along the way, the thorny issue of cost is also being addressed. At the component level, silicon IGBTs are vastly cheaper than the SiC equivalent, and are not going to disappear from power applications anytime soon. But Tier-1 manufacturers and OEMs have indicated that implementing high-power density SiC into, say, an inverter design, cuts costs at a system level thanks to the space and weight savings resulting from the need for fewer components.

But where does this leave GaN? This wide-bandgap semiconductor has yet to witness the success of SiC in the EV sector. But thanks to its high frequency operation and efficiencies, OEMs are either eyeing the technology with intense interest or have development programs underway.

Early days

GaN power devices can already be found in low-volume, high-end photovoltaic inverters and are being increasingly used in fast chargers for a range of mobile devices including smartphones. Indeed, Ireland’s Navitas, Power Integrations of the U.S. and China’s Innoscience are all manufacturing GaN power ICs for the burgeoning fast-charger market.

Given this activity, GaN power device revenues are estimated to reach around $100 million in 2021. But as GaN device suppliers look to enter other markets to raise volumes, this figure is expected to swell to that $1 billion by 2026. And the EV/HEV market is the first to watch.

It’s early days for GaN in EVs. Many power GaN players have developed and auto-qualified 650-V GaN devices for onboard chargers and DC/DC conversion in EVs/HEVs, with myriad partnerships already formed with automotive businesses.

For example, Canada-based GaN Systems supplies its devices to U.S. EV start-up Canoo for onboard chargers, and has also partnered with Canada-based EV motor drive supplier FTEX to integrate 650-V GaN power devices into systems for e-scooters. At the same time, California-based Transphorm has teamed up with automotive supplier Marelli to provide devices for onboard charging and DC/DC conversion.

STMicroelectronics is expected to supply its yet-to-be auto-qualified devices to Renault for EV applications. EPC, currently delivering automotive-qualified low-voltage GaN devices, is working with French-based Brightloop to develop affordable power supply converters for off-high way and commercial vehicles. Last year, Texas Instruments also qualified its 650-V GaN devices for automotive applications.

But as the onboard charger and DC/DC market segments gather momentum, the billion-dollar question, quite literally, for GaN is, Will the technology make it to the main inverter of EV powertrains, reaping spectacularly high volumes comparable to SiC technology?

Early industry developments indicate this is possible.

In February 2020, Nexperia of the Netherlands partnered with the U.K. consultant Ricardo to develop a GaN-based EV inverter design. The announcement was swiftly followed by VisIC Technologies of Israel partnering with German auto supplier ZF to develop GaN semiconductors for 400-V driveline applications.

Then, in September, GaN Systems signed a $100 million deal with BMW to provide the capacity to manufacture GaN power devices for the German automaker’s EVs, providing solid evidence that OEMs are serious about GaN.

In another truly significant development, Navitas will become a publicly-traded company with a market value of $1.04 billion by combining with special-purpose acquisition company Live Oak Acquisition. The GaN power IC player recently announced it will supply devices to Swiss-based Brusa HyPower for onboard chargers and DC/DC converters. As a public company, it intends to put its weight behind product development for EVs/HEVs and other markets.

Beyond those deals, partnerships and mergers, early work on GaN modules also indicates that the compound semiconductor is following in the footsteps of SiC, with industry players gearing up for more widespread industry integration. For example, GaN Systems is offering a power evaluation module kit to design engineers while Transphorm has been working with Fujitsu General Electronics on a GaN module that targets industrial and automotive applications.

So, what next for both SiC and GaN? As manufacturers of power SiC devices anticipate a multi-billion-dollar EV market, will GaN experience the same success? Widespread OEM adoption of GaN in drivetrain inverters would radically impact market forecasts. But right now, we can only wait and see.

Authors:

–Ahmed Ben Slimane is a technology and market Analyst at Yole Développement specializing in compound semiconductors and emerging substrates;

–Ezgi Dogmus is team lead analyst in compound semiconductor and emerging substrates within Yole’s Power & Wireless Division;

–Poshun Chiu is a Yole technology and market analyst specializing in compound semiconductor and emerging substrates.

From:  https://www.eetimes.com/sic-and-gan-a-tale-of-two-semiconductors/#