What’s the Plan Behind ST’s Recent Plunge Into Gallium Nitride?

March 09, 2020 by Gary Elinoff

With an eye on electric vehicles, ST took the majority stake in GaN pioneer Exagan.

ST’s new investment in Exagan, a French gallium nitride (GaN) innovator, will provide it with an accelerated pathway toward developing products for the exploding market of automotive electronics.

GaN, like silicon carbide (SiC), is a wide bandgap (WBG) semiconductor. WBG devices' advantage over silicon devices is that they can handle more power at higher speeds than can classical silicon devices. While SiC is a well-established technology, GaN is fundamentally more power-efficient than SiC is—and the fact that it can operate at higher frequencies enhances this vital advantage.


The Two Players

ST is a global semiconductor leader involved in producing energy-efficient products and solutions for power electronics. The company has been a player in the wide-bandgap game since at least 1996, and the purchase of Exagan represents a continuation of a very consistent commitment.

Exagan is a small French company entirely devoted to GaN. Its mission statement is to “accelerate the adoption of power conversion with 99%+ efficiencies.” Their flagship products are their G-FET and G-DRIVE ICs, designed for easy integration.


Rendering of the G-FET and G-DRIVE chips. Image from Exagan.


The Surprisingly Long History of ST and Wide-Bandgap Technologies

ST is already a big player in silicon carbide (SiC). Its previous acquisition of Norstel and partnership with Wolfspeed helped move along that pathway.


ST offers several options for SiC MOSFETs and diodes. Images used courtesy of STMicroelectronics


But ST is also no stranger to gallium nitride. The company previously partnered with MACOM in 2018 to develop GaN wafers for the latter’s RF applications. In the same year, ST and Leti joined forces on GaN power switching devices.

More recently, ST entered into a collaboration with TSMC to develop GaN technology and to bring it to market. Because TSMC is the world's largest semiconductor foundry, this is an extremely significant partnership.

While they don't currently offer ST-branded GaN devices, they've had a GaN technology page live on their website since at least April of 2019, showing premeditation for a GaN strategy a long time in the making.


Why the World Needs WBG Semiconductors

Why so much earnest investment in WBG technologies? Here are a couple of compelling reasons ST may have in mind when pursuing additional WBG opportunities.


The Electrification of the Automobile

A look under the hood of your car will reveal the extent of the ongoing process of electrification. Much of the old hydraulic piping has been replaced with electronic cabling carrying both power and information. 

WBG semiconductors can handle the power, and they can switch on and off hundreds of thousands of times a second, which means they can do it efficiently and take up very little precious onboard space to do it in. These capabilities are essential to everything from vehicle charging devices to running the infotainment systems.


The growth of the EV vertical means changes for automotive applications and infrastructure. Image used courtesy of Exagan


Beefing Up the Power Grid

Think of the amount of petroleum power required to power America’s vast fleets of cars and trucks.

When fully electrically-powered vehicles become commonplace, the amount of electrical power necessary to replace petrochemicals will be huge. WGB semiconductors will be a crucial element here, too. Effective and efficient power conversion capabilities will be especially critical for the all-DC power grids now anticipated. 

ST is even now involved in creating designs and components for DC vehicle chargers. For passenger vehicles, these devices will take about 150 kW. A vast investment in the electric grid will become necessary to provide the needed power to untold thousands of these devices. 


Moving from Strength to Strength

But, let’s not gainsay SiC devices because they do can do a great job as far as they go. It’s just that, depending on who you ask, GaN will do it better. 

Indeed, according to Jean-Marc Chery, President and CEO of STMicroelectronics, “ST has built strong momentum in silicon carbide and is now expanding in another very promising compound material, gallium nitride, to drive adoption of the power products based on GaN by customers across the automotive, industrial, and consumer markets.”

ST has in the past and will continue to follow a pathway to the future that includes a solid foundation of internal development and partnerships, and perhaps acquisitions. As Mr. Chery states, “The acquisition of a majority stake in Exagan is another step forward in strengthening our global technology leadership in power semiconductors and our long-term GaN roadmap, ecosystem, and business.” 



Have you worked with WBG semiconductors before? Do you agree with ST's optimism that they will continue to gain dominance in the EV space? Share your experiences with GaN and SiC devices in the comments below.