Semiconductor Leaders Bank on the Power of WBGs

The invention of the silicon integrated circuit (IC) almost 60 years ago paved the way for modern computing and today’s tech-fueled electronics era. While silicon isn't going anywhere, in the past few years, alternative semiconductor materials have taken the stage as strong competitors—especially in the automotive and space industries. 

This is occurring with Moore’s law as the backdrop, the axiom of Gordon Moore, co-founder of Intel, that the number of transistors in an IC doubles roughly every two years. 

 

An estimate from 2006 on how Moore's law would progress to 2025. Image used courtesy of BCA Research and Colleaga

 

It’s not a situation that’s sustainable because as more transistors are packed into a smaller space, more heat is generated. And as time goes by, we’re very quickly approaching silicon’s physical limit as design engineers struggle to meet market demands for new devices with greater power density and energy efficiency.

While we don’t know for sure when we’ll reach this limit—forecasters, including Moore himself, expect it to happen by around 2025—what we do know is that we need semiconductor alternatives that can handle the constraints of miniaturization better than silicon.

That’s where semiconductors like silicon carbide (SiC) and gallium nitride (GaN), wide bandgap (WBG) semiconductors, come in. 

 

The Roadmap for Wide-Bandgap Semiconductors

WBG semiconductors have drummed up a lot of excitement throughout the semiconductor industry, especially where power electronics are concerned. 

The primary benefit of WBGs is that their bandgaps—the energy difference between insulating and conducting states—are much greater than that of silicon. As a result, devices using WBGs can handle higher voltages, operate at higher temperatures, and achieve higher frequencies while using less energy. 

 

The physical properties of silicon compared to other wide-bandgap semiconductors. Image used courtesy of Toshiba

 

However, it’s a fairly new technology, and devices using WBG semiconductors currently cost more than their silicon-based cousins, which benefit from a proven track record. 

To encourage the use of WBG semiconductor technology, the IEEE Power Electronics Society (PELS) released their WBG power semiconductors roadmap in September 2019, a strategic look at the long-term landscape of WBG, its future, and what the possibilities are—well worth a read for those seeking more contextual information about WBG technology. 

 

Semi Leaders Expanding Beyond Silicon ICs

This year has seen a lot of activity from big semiconductor industry leaders moving to explore technologies like SiC and GaN that offer them more power. 

 

ST Advances on GaN

In March, STMicroelectronics—which has already established a strong presence in the SiC market having first began working on WBG materials in 1996 with SiC MOSFETs and diodes—acquired a majority stake in Exagan, a French GaN innovator. 

While SiC and GaN are both WBG semiconductors, they address different parts of the power IC market. Thus, the acquisition will allow ST to meet different customer demands across industrial markets. 

 

Exagan offers two main GaN products: G-FET and G-DRIVE. Image used courtesy of Exagan

 

ST says that its GaN products will address a variety of applications such as power factor correction, DC/DC converters, and adaptors in segments like space, industry, and telecoms. Future developments of ST GaN products will target the automotive sector with on-board chargers for electric vehicles and mild-hybrid DC-DC converters.

More recently, Cree and Infineon were involved in deals that focus on expanding SiC development efforts. 

 

Cree Offloads LED Assets to Focus on SiC 

In mid-October, Cree announced the $300 million sale of its LED business to SMART Global Holdings, Inc., a transaction that represents a milestone in Cree’s transformation to a “pure-play global semiconductor powerhouse” that will focus on SiC and GaN devices. Cree’s product line-up already includes SiC, mainly in its Wolfspeed product family, but the company is attempting to hone in exclusively on SiC by selling off other elements of the business. 

 

Cree 650V SiC MOSFETs. Image used courtesy of Cree

 

Cree’s CEO, Gregg Lowe, said that the sale will position the company with a strategic focus capable of leading the transition from Si to SiC and the capital to support continued investments in growth opportunities across electric vehicle, 5G, and industrial applications. 

 

Infineon Ups Is SiC Boule Supply

Then in November, Infineon signed a supply agreement with GT Advanced Technologies (GTAT) for SiC boules in response to steadily increasing demand for SiC-based switches for both industrial and automotive applications. 

 

Infineon's agreement with GTAT will allow the company to meet its customer's growing demand for SiC-based technology. Image used courtesy of Infineon

 

“With the supply agreement we have now concluded, we ensure that we will be able to meet the rapidly growing demand of our customers with a diversified supplier base. GTAT’s high-quality boules will provide an additional source for competitive SiC wafers fulfilling the best-in-class material standards now and in the future,” said Peter Wawer, President of Infineon’s Industrial Power Control Division. 

 

The Growing Influence of WBG

It's activities like these from semiconductor firms that paints a clear picture: WBG semiconductors like SiC and GaN will play a pivotal role as Si-based ICs begin to reach their physical limits and lose their momentum. No doubt, then, we’ll soon begin to see much more of a focus on WBG technologies from semi companies both big and small.