Ralf’s GaN & SiC News (July 18, 2024)

Welcome to the latest edition of my newsletter on silicon carbide, gallium nitride, and other wide-bandgap semiconductor materials. If you want to get covered, please reach out to me via [email protected]

Miscellaneous News

AI to drive 160% increase in data center power demand – an opportunity for WBG power semiconductors

For years, data centers displayed a remarkably stable appetite for power, even as their workloads mounted. Now, as the pace of efficiency gains in electricity use slows and the AI revolution gathers steam, 高盛 Research estimates that data center power demand will grow 160% by 2030. This poses a great opportunity for WBG power semiconductors.

At present, data centers worldwide consume 1-2% of overall power, but this percentage will likely rise to 3-4% by the end of this decade. In the US and Europe, this increased demand will help drive the kind of electricity growth that hasn’t been seen in a generation. Along the way, the carbon dioxide emissions of data centers may more than double between 2022 and 2030.

In a series of three reports, Goldman Sachs Research analysts lay out the US, European, and global implications of this spike in electricity demand. It isn’t that our demand for data has been meager in the recent past. Data center workloads nearly tripled between 2015 and 2019. Through that period, though, data centers’ demand for power remained flattish, at about 200 terawatt-hours per year. In part, this was because data centers kept growing more efficient in how they used the power they drew, according to the Goldman Sachs Research reports, led by Carly Davenport, Alberto Gandolfi, and Brian Singer.

But since 2020, the efficiency gains appear to have dwindled, and the power consumed by data centers has risen. Some AI innovations will boost computing speed faster than they ramp up their electricity use, but the widening use of AI will still imply an increase in the technology’s consumption of power. A single ChatGPT query requires 2.9 watt-hours of electricity, compared with 0.3 watt-hours for a Google search, according to the International Energy Agency. Goldman Sachs Research estimates the overall increase in data center power consumption from AI to be on the order of 200 terawatt-hours per year between 2023 and 2030. By 2028, our analysts expect AI to represent about 19% of data center power demand.

In tandem, the expected rise of data center carbon dioxide emissions will represent a “social cost” of $125-140 billion (at present value), the analysts believe. “Conversations with technology companies indicate continued confidence in driving down energy intensity but less confidence in meeting absolute emissions forecasts on account of rising demand,” they write. They expect substantial investments by tech firms to underwrite new renewables and commercialize emerging nuclear generation capabilities. And AI may also provide benefits by accelerating innovation — for example, in health care, agriculture, education, or in emissions-reducing energy efficiencies.

Interview with Gauthier Chicot, CEO and co-founder of DiamFab

In this episode of Wine Down Friday, Gauthier Chicot , CEO and co-founder of DIAMFAB , shares his journey from academia to entrepreneurship. He discusses the advantages of diamond in power electronics, emphasizing its superior electrical and thermal properties.

Gauthier reveals his vision for DiamFab’s growth, balancing innovation with practical business aspects through strategic partnerships. Looking ahead, DiamFab aims to make diamond technology an industrial reality, enhancing applications with its exceptional performance and cost-effectiveness.

High-temperature and high-electron mobility MOSFET based on N-type diamond

Diamond holds the highest figure-of-merit among all the known semiconductors for next-generation electronic devices far beyond the performance of conventional semiconductor silicon. To realize diamond integrated circuits, both n- and p-channel conductivity are required to develop diamond CMOS devices, as those established for semiconductor silicon. However, diamond CMOS has never been achieved due to the challenge in n-type channel MOSFETs.

Here, researchers from the National Institute for Materials Science (NIMS) present an electronic-grade phosphorus-doped n-type diamond epilayer with an atomically flat surface based on step-flow nucleation mode. Consequently, n-channel diamond MOSFETs are demonstrated. The n-type diamond MOSFETs exhibit high field-effect mobility around 150?cm2/(V s) at 573?K, the highest among all the n-channel MOSFETs based on WBG semiconductors. This work enables the development of energy-efficient and high-reliability CMOS integrated circuits for high-power electronics, integrated spintronics, and extreme sensors under harsh environments.

Meiyong Liao , Huanying Sun, Satoshi Koizumi 小泉訓 (2024). High-Temperature and High-Electron Mobility Metal-Oxide-Semiconductor Field-Effect Transistors Based on N-Type Diamond. Advanced Science, 11(13), 2306013. https://doi.org/10.1002/advs.202306013

WiPDA-Europe takes place in Cardiff (Wales) from September 16 to 18

The second bi-annual IEEE Workshop on Wide Bandgap Power Devices and Applications in Europe (WiPDA-Europe) will be held in Cardiff, the capital city of Wales, United Kingdom, from September 16 to 18, 2024. WiPDA-Europe serves as a platform for device scientists, circuit designers, and application engineers to converge, exchange valuable insights, and explore the latest advancements in WBG power devices and their diverse applications. This event promises an enriching experience through technical sessions, tutorials, and thought-provoking keynotes delivered by distinguished leaders from both industry and research sectors.

WiPDA-Europe 2024 is not only a space to showcase technological updates and research findings but also a forum to share practical experiences and explore potential applications of WBG power devices. The conference will feature an exposition where participants can engage with cutting-edge technologies and innovations.

After the presentation at the workshop, accepted papers will be submitted for inclusion into IEEE Xplore subject to meeting IEEE Xplore’s scope and quality requirements.

• Date: September 16 to 18
• Venue: Royal Welsh College of Music and Drama, Cardiff, Wales, United Kingdom

Master program in power electronics devices and technologies at the University of Catania and ST

The third edition of the second-level master’s program in “Power Electronics Devices and Technologies” organized by the Department of Electrical, Electronic and Information Engineering (DIEEI) of the Università di Catania together with 意法半导体 has been announced. The goal of the master’s program is to train specialists in technologies based on WBG semiconductors.

A maximum of 30 participants will be admitted to this master’s degree program. The top 10 in the eligible list will be awarded a scholarship. Those ranking from 11th to 20th will receive a contribution to the tuition fee. Applications must be submitted by September 30, 2024.

“Training specialized profiles and skills in the field of power electronics with multidisciplinary knowledge is essential for fostering technological innovation. Theoretical lectures held at the University of Catania and internships at ST’s Catania site will allow students to experience working with a leader in power semiconductors,” said Gianfranco Di Marco , Power Transistor Sub-Group, Chief of staff and Technical Communication Manager at STMicroelectronics.

Virtual Open House at CPES

Are you a prospective graduate student or postdoctoral fellow looking for a world-leading education in power electronics? Center for Power Electronics Systems, Virginia Tech faculty, students, and staff, invite prospective graduate students and postdoctoral fellows interested in joining CPES, at Virginia Tech, to participate in the first “Virtual Open House” online recruiting event, to learn more about the center’s comprehensive research program, its operations, and graduate research assistantships (GRA) and research faculty opportunities.

Nexperia partners with Aixtron for 200-mm SiC and GaN power

AIXTRON SE supports Nexperia in the ramp-up of its 200-mm volume production for SiC and GaN power devices. With the new G10-SiC for the 200mm SiC volume ramp, Nexperia is placing a repeat order for Aixtron SiC tools. This is complemented by an order for Aixtron G10-GaN tools.

“As we advance our technological capabilities and market presence in high-power semiconductor production, our strategic partnership with Aixtron is transformative. With the new G10 tools in our Hamburg facility, we are poised for further advancements in our production capabilities,” said Achim Kempe , COO at Nexperia.

Gallium Nitride News

India-based L&T Semiconductor eyes mid-term GaN fab development

L&T Semiconductor Technologies , a subsidiary of Indian conglomerate Larsen & Toubro , plans to focus on semiconductor IC design in its initial phase, followed by developing a GaN/SiC fabrication facility in the second phase, DIGITIMES Asia reports.

According to industry sources, in phase one, L&T Semiconductors will focus on the design & development of niche ICs for targeted markets and outsource the semiconductors manufacturing and packaging like other fabless companies. In phase two, once there are enough chip sales, and ready for effective utilization of fabs for production, they may set up their own fabs, focusing on high-power devices like gallium nitride and silicon carbide.

The company aims to partner with global players for manufacturing and packaging selectively. It intends to cover segments such as automotive, industrial, networking, and energy, utilizing both digital and analog technologies. L&T Semiconductor has already begun conversations with fabs like TSMC and GlobalFoundries, sources added. On the customer side, the company is seeing active interest from various players in India and overseas.

This initiative could bolster India’s ambitions to become a major player in the global semiconductor Design & Manufacturing sector. Earlier this year, the country approved three significant proposals in this domain, including wafer fabrication and OSAT plants.

Annual YESvGaN newsletter published

An exciting third YESvGaN - Wide bandgap power at silicon cost project year has come to an end. Over the past 12 months, the partners have made significant progress in epitaxy, processing, and application. In this newsletter, you can find an excerpt of the highlights from their work package.

They are delighted to report an increase in GaN drift layer thickness, resulting in a blocking voltage of up to 1200 V. Additionally, they have achieved full process integration on 200 mm GaN-on-silicon substrates, advancements in assembly and interconnection technology of membrane transistors, and the development of application demonstrators based on GaN-ready half-bridge power modules. Notably, YESvGaN has completed its first fully vertical GaN-on-silicon Trench MOSFET demonstrator, showing the feasibility of vertical GaN membrane transistors on foreign substrates for future power transistors.

Qromis recognized with Frost & Sullivan’s 2024 Global Enabling Technology Leadership Award

弗若斯特沙利文公司 recently researched the GaN semiconductors industry and, based on its findings, recognizes Qromis, Inc. with the 2024 Global Enabling Technology Leadership Award.

QST, which is assembled and manufactured in traditional CMOS fabs, is very similar to mainstream silicon-on-insulator (SOI) substrates for manufacturing processing and cost and utilizes energy-efficient state-of-the-art semiconductor process tools with an over 98% yield and a process cycle time of less than 7 days. This is a critical component of the QST innovation which was carefully designed per the projected cost and sustainability/net zero requirements in the industry, and very different than manufacturing of native GaN substrates or non-native SiC and sapphire substrates.

One of the critical features of QST technology is the enablement of high high-yielding and low-cost GaN epitaxy growth process via robust wafer shape control, epitaxy uniformity, and elimination of costly and complex strain management layers which result in the reduction of epitaxy growth time by 50%. This is an extremely important and leap-forward achievement for the overall cost reduction of GaN devices.

Frost & Sullivan commends Qromis for its innovative QST, which effectively addresses scalability, cost, and reliability challenges in the GaN semiconductors market. QST will play a crucial role in expediting the commercialization of highly reliable GaN devices while showcasing versatility in applications and demonstrating scalability for future advancements,” said Prabhu K. , Industry Principal for the Semiconductors program at Frost & Sullivan.

Observation of 2D-magnesium-intercalated GaN superlattices

Since the demonstration of p-type GaN through doping with substitutional magnesium (Mg) atoms, rapid and comprehensive developments, such as blue light-emitting diodes, have considerably shaped our modern lives and contributed to a more carbon-neutral society. However, the details of the interplay between GaN and Mg have remained largely unknown.

Here, a team of researchers from 名古屋大学 led by Nobel Laureate Amano Hiroshi observe that Mg-intercalated GaN superlattices can form spontaneously by annealing a metallic Mg film on GaN at atmospheric pressure. To their knowledge, this marks the first instance of a two-dimensional metal intercalated into a bulk semiconductor, with each Mg monolayer being intricately inserted between several monolayers of hexagonal GaN. Characterized as an interstitial intercalation, this process induces substantial uniaxial compressive strain perpendicular to the interstitial layers. Consequently, the GaN layers in the Mg-intercalated GaN superlattices exhibit an exceptional elastic strain exceeding -10% (equivalent to stress of more than 20?GPa), among the highest recorded for thin-film materials. The strain alters the electronic band structure and greatly enhances hole transport along the compression direction. Furthermore, the Mg sheets induce a unique periodic transition in GaN polarity, generating polarization-field-induced net charges.

These characteristics offer fresh insights into semiconductor doping and conductivity enhancement, as well as into elastic strain engineering of nanomaterials and metal-semiconductor superlattices.

Jia Wang, 蔡文韬 , Weifang Lu , Shun Lu, Emi Kano, Verdad C. Agulto, Ph.D. , Biplab Sarkar , Hirotaka Watanabe, Nobuyuki Ikarashi, Toshiyuki Iwamoto, Makoto Nakajima, Yoshio Honda, Hiroshi Amano. Observation of 2D-magnesium-intercalated gallium nitride superlattices. Nature 631, 67–72 (2024). https://doi.org/10.1038/s41586-024-07513-x

Advanced Energy acquires Airity Technologies

Advanced Energy Industries GmbH announced the acquisition of Airity Technologies , a California-based provider of next-generation, high-voltage power conversion products and technologies for applications in semiconductor, industrial, and medical markets. Advanced Energy expects the acquisition to be immaterial to 2024 financial forecasts. Terms were not disclosed.

Airity Technologies adds a portfolio of GaN-based high frequency, power conversion, and pulsing technologies, which enable a step function improvement in power density and response time. Leveraging Airity’s proven technologies, Advanced Energy will address a broader range of applications in its target markets.

“The acquisition of Airity Technologies extends our technology leadership and will accelerate our innovation in the precision power conversion market. We have worked closely with the Airity team over the past year and are very excited that they will be joining Advanced Energy,” said Steve Kelley , Advanced Energy’s president and CEO.

Beneq and Fraunhofer IAF join GaN Valley consortium

With Beneq and Fraunhofer IAF , GaN Valley announced two new members to join its community. These leading companies are joining us to drive innovation and excellence in the semiconductor industry.

Navitas presents a 400-W LLC converter using a highly integrated half-bridge GaN IC

Portable workstations are high-performance laptops that allow professionals to run applications such as photo and video editing, gaming, 3D rendering, CAD/CAM tasks and more. Such devices, equipped with power-hungry CPUs and GPUs, require a power supply unit (PSU) in the range of 300 W to 500 W. The design of such a PSU is intrinsically difficult because of space and thickness constraints that require high power densities. Other applications with similar power requirements include wide-screen OLED TVs, as well as desktops that integrate the main computer components—CPU, monitor, and speakers—into a single sleek unit.

In a paper presented at APEC in February 2024, Navitas Semiconductor showcased a converter prototype with LLC topology converting 400 V DC to 24 V DC. The converter module sports a profile of only 8 mm with a remarkable power density (21.5 kW/L). Peak efficiency is 98.1%, whereas full-load efficiency (400 W) reaches 97.4%.

Silicon Carbide News

A Conversation with Tony Chiang (CEO) and Ajay Poonjal Pai, Sanan Semiconductor

With Maurizio Di Paolo Emilio , Tony Chiang, CEO of Sanan Semiconductor , and Dr. Ajay Poonjal Pai , Head of WBG Solutions, discuss the latest advancements in SiC technology, the benefits of Sanan Semiconductor’s vertically integrated model, the role of SiC in EVs and renewable energy, and future trends in the power electronics market at the PCIM .

Proof of concept for an eFuse in 800 V automotive applications

Asahi Kasei Microdevices (AKM) and Silicon Austria Labs (SAL) (SAL) have completed a joint proof of concept of the eFuse technology in high-voltage applications utilizing SiC-based power devices. The results show that the eFuse technology can significantly improve safety, as well as reduce material and maintenance costs of systems such as on-board chargers (OBC) in automobiles.

AKM is producing the CZ39, a coreless current sensor with a response time of 100 ns. Its fast response capability and high accuracy allow for precise detection of overcurrent and quick system shutdown. In a joint technical verification together with the Austrian research center SAL, AKM has developed the eFuse system which solves the challenges of conventional protection systems using mechanical fuses. This solution provides the overcurrent and short circuit protection required for next-generation high-voltage EV systems with SiC- and GaN-based power devices, such as OBCs. Furthermore, the current sensor integrated into the eFuse can efficiently regulate the current in connected subsystems, thereby reducing the overall part count.

Semikron Danfoss to double sales in automotive power modules, Peter Sontheimer says

In an interview with Engelbert Hopf for Markt&Technik , Peter Sontheimer , Senior Vice President of the Industry Division of Semikron Danfoss and Managing Director of Semikron Danfoss International, said that the overheated situation in the SiC supply chain of the last two years is behind us. Delivery times have shortened again, and availability has returned. The current breather is just a short-term sideways movement in the market.

He said that power electronics has just begun to contribute to the necessary decarbonization and thinks of the newly emerging energy storage markets. However, the hype topic of AI will continue to push demand for power electronics, as this will also significantly increase the need for electrical energy. Global politics may be able to slow down this development somewhat by acting clumsily, but it can no longer stop it, Sontheimer added.

As proof, Sontheimer mentioned that Semikron Danfoss has doubled its sales in automotive power modules in 2023 and will double them again in 2024. He continues to believe that these ambitious sales targets are realistic.

Optimized SiC boule fabrication

In this article for Compound Semiconductor Magazine & CS International Conference , James Carl from USACH shares some interesting insights into SiC boule fabrication as crystal growth technologies are highly proprietary, and for some producers have been developed in secret over decades.

The ever-growing demand for SiC material and devices motivates those working in this industry to innovate and enhance their production processes. Helping them in this endeavor is the BoulePro-200AX produced by USACH. Designed to meet the evolving needs of the SiC industry, this industry-standard tool for fabricating boules is setting new benchmarks for efficiency and quality, while empowering manufacturers to meet the surging demand for high-quality materials.

One shortcut to EMI compliance with power modules

In this blog post, Brian DeBoi from Wolfspeed discusses power modules as an option for reducing electromagnetic interference (EMI). He proposes considering coupling early during design. By strategically optimizing the small parasitic couplings within the system, for example to the heatsink, or by balancing passive components within the system around the parasitic couplings, emissions can be reduced significantly without using EMI filters.

This provides designers another avenue to optimize their system and minimize emissions while still taking advantage of the efficiency and power density improvements offered by silicon carbide. However, this approach requires a deep understanding of the components and system that is not always intuitive to designers.

Therefore, DeBoi proposes the usage of power modules over discrete components and takes a deeper dive into the impact of heatsink coupling, and distribution of capacitance and proves this with an EMI simulation

A short history of silicon carbide

Join Microchip Technology Inc. on a 6-minute journey through time to see how SiC has evolved and continues to shape our world. From its accidental discovery in the late 19th century by Edward Acheson to its vital role in modern electronics, power systems, and industrial applications, this lighthearted animation delves into the key milestones and advancements in silicon carbide technology.

Novel clamping modulation for three-phase buck-boost AC choppers

Three-phase AC choppers feature output voltage amplitude controllability and enable more compact system realizations compared to autotransformers. For the practical realization advantageously standard power transistors with unipolar voltage blocking capability such as SiC MOSFETs can be employed as a naturally resulting offset voltage between the grid and the input-stage starpoint ensures purely positive power transistor voltages.

This offset voltage is, however, not strictly defined and may drift to higher voltage values, resulting in high power transistor voltage stresses and finally a potential overvoltage breakdown. Traditionally, the offset voltage drift is prevented by introducing discharge resistors across the input-stage capacitors which, however, results in substantial ohmic losses.

This paper from researchers at 瑞士苏黎世联邦理工学院 analyzes the offset voltage formation in AC choppers and proposes a novel clamping modulation scheme that ensures a strictly defined and minimum time-varying offset voltage without the need for discharge resistors. Theoretical analyses and circuit simulations are finally experimentally verified with a 400?V (RMS, line-to-line) 50?Hz grid-connected three-phase buck-boost AC chopper with 3?kW rated?power.

David Menzi , Aobo Yang , Saransh Chhawchharia , Johann KOLAR (2024). Novel clamping modulation for three-phase buck-boost ac choppers. Electronics Letters, 60(13), e13210. https://doi.org/10.1049/ell2.13210

Wolfspeed presents topside-cooled SiC power devices

Wolfspeed is expanding its portfolio of SiC MOSFET & Schottky diode discrete products with the addition of the new topside cooled (TSC) package: the U2. With options ranging from 650 V to 1200 V, these TSC products significantly increase system-level power density and efficiency, while improving thermal management and board layout flexibility.

Wolfspeed’s upcoming 13 kW motor drive reference design, featuring the TSC U2 package, demonstrates the benefits of U2 devices for 10 kW+ EV HVAC systems, which support thermal management of the cabin, battery, and electronics. Optimizing the efficiency and operating temperature range of the HVAC system with the implementation of SiC enables systems designers to bring fast charging to the driver in under 15 minutes, while also extending the driving range per charge for the lifetime of the car.