Ralf’s GaN & SiC News (November 16, 2023)
Welcome to the latest edition of my newsletter on and. If you want to get covered, please reach out to me via [email protected]
Gallium Nitride News
Interface Charge Engineering for Improved Breakdown Performance
This work from a team of researchers from the Southern University of Science & Technology , 香港理工大学 , the 新加坡国立大学 , and Maxscend Microelectronics adopts interface charge engineering to fabricate normally-off MIS-HEMTs on an in situ SiN?/AlGaN/GaN platform using an in situ O? treatment performed in the atomic layer deposition system. The combination of in situ SiN? passivation and an O?-treated Al?O?/AlGaN gate interface allows the device to provide an excellent breakdown voltage of 1498?V at a low specific on-resistance of 2.02?mΩ?cm2.
The threshold voltage is increased by 2?V by significantly compensating the net polarization charges by more than five times with O? treatment, reducing the interface traps, and improving the high-temperature gate stability. Furthermore, a physical model of fixed charges at the Al?O?/AlGaN interface is established based on dielectric thickness-dependent linear fitting and numerical calculations. The matched device performance and simulated energy band bending elucidate the O?-treated fixed-charge modulation mechanism, providing a practical method for producing normally-off GaN MIS-HEMTs.
JiaQi He, KangYao Wen, PeiRan Wang, MingHao He, FangZhou Du, Yang Jiang, ChuYing Tang, Nick Tao, Qing Wang, Gang Li, HongYu Yu; Interface charge engineering on an in situ SiNx/AlGaN/GaN platform for normally off GaN MIS-HEMTs with improved breakdown performance. Appl. Phys. Lett. 4 September 2023; 123 (10): 103502. https://doi.org/10.1063/5.0169944
VisIC Presents Device in Advanced Top Side Cooled Isolated Package
VisIC Technologies Ltd. introduced the V22TG D3GAN power package. This is the outcome of a collaboration with KYOCERA AVX Components (Salzburg) GmbH announced one year ago. Samples will be available in the first quarter of 2024.
The leaded topside cooled isolated package promotes excellent thermal management to ensure optimal performance and reliability in demanding automotive environments. Moreover, the isolated package enhanced the ease of assembly due to no additional isolation needed. The 650?V/22 mΩ device is tested to meet automotive industry standards, making it suitable for a wide range of automotive applications, like OBC, Fuel Cell, and hybrid electric vehicles. The V22TG D3GAN is designed to support various system configurations, including paralleling of devices, full-bridge, half-bridge topologies, and power factor correction (PFC) circuits.
Webinar with Alex Lidow: The Evolution of Low-voltage Power in Automotive Electronics
Over the past three decades, automotive electronics have undergone a remarkable evolution, transitioning from traditional internal combustion engines (ICE) to the emergence of battery electric vehicles (BEVs). This progression has not only transformed the way vehicles operate but has also driven significant changes in power distribution architectures and semiconductor components.
In this PSMA (Power Sources Manufacturers Association) webinar, Alex Lidow , co-founder and CEO of EPC - Efficient Power Conversion , examines the three major stages of this evolution – from ICE to mild hybrid (MHEV) to BEV – and explores the role of low-voltage power distribution and next-generation power electronics in shaping the automotive landscape.
Magnesium Activation Effect on Pinch-Off Voltage of Normally-off p-GaN HEMTs
The role of Mg doping and its electrical activation on the off-state of p-GaN/AlGaN/GaN HEMTs has been investigated in this work by researchers from 意法半导体 , Università degli Studi di Modena e Reggio Emilia , and CNR-IMM (Istituto per la microelettronica e microsistemi) . Firstly, the effect of different Mg doping profiles has been studied with the help of TCAD simulations, with the objective of analyzing the band diagrams of the structure. Then, it has been shown how experimental Capacitance–Voltage measurements can be useful to obtain information on the net acceptor concentration in the p-GaN.
As a result, devices with an undoped (magnesium-free) GaN gate have been experimentally compared to devices whose p-GaN gate has been activated via a reference annealing process. Finally, results on a device characterized by an improved p-GaN activation have been presented and compared, showing improvements on several parameters of both off- and on-state, thus underlining the key role of the Mg activation process in the overall performances of normally-off GaN HEMTs.
Giovanni Giorgino , Giuseppe Greco , MAURIZIO MOSCHETTI , Cristina Miccoli, Maria Eloisa Castagna, Cristina Tringali , Patrick Fiorenza , Fabrizio Roccaforte , Ferdinando Iucolano , "Study of Magnesium Activation Effect on Pinch-Off Voltage of Normally-Off p-GaN HEMTs for Power Applications" Crystals 2023, 13, no. 9: 1309. https://doi.org/10.3390/cryst13091309
Miscellaneous News
Anwenderforum Leistungshalbleiter 2023
The 7th Power Semiconductors User Forum (Anwenderforum Leistungshalbleiter) of Markt&Technik is taking place in Munich on November 22 and 23, 2023. This event which Engelbert Hopf and I conceived provides guidance for developers and technical purchasers in power electronics. The interesting program provides essential basics and application tips on MOSFET & Co.
Keynote speakers are Jean-Christophe ELOY , CEO and President of Yole Group , who will discuss which forces are the driving markets and technologies in the power electronics business, and Peter Sontheimer , Senior Vice President Division Industry at Semikron Danfoss , who will talk about SiC switches for industrial applications. Other well-known speakers from the world of wide-bandgap semiconductors are Frank Heidemann ( SET GmbH - Smart Embedded Technologies ), Dieter Liesabeths ( VisIC Technologies Ltd. ), Alfred Hesener ( Navitas Semiconductor ), Andrea Bricconi ( Cambridge GaN Devices Ltd ), and Douglas Bailey ( Power Integrations ).
Embedded PCB packaging of WBG Power Electronics
Improved packaging of these wide bandgap (WBG) components is essential to reduce parasitics, provide efficient heat transfer, and promote system-level integration. In this article published in Power Electronics News, Sonu Daryanani highlights some of the advantages and challenges of embedded printed circuit board (PCB) packaging of WBG power electronics.
The following approaches are discussed:
imec Webinar: Compound Semiconductors: Technology and Market Overview
The compound semiconductor market is growing rapidly. Technology innovation and new products play a key role in the compound semiconductor industry. This presentation held by Dr. Ahmed Ben Slimane ( imec ) will provide a technology overview of compound semiconductors, with a special focus on the following materials: SiC, GaN, GaAs, InP, and SiGe.
Finally, the presentation will discuss some examples of technology roadmaps and evolution, such as the development of new SiC-based and GaN-based power devices for electric vehicles, the emergence of GaN-based radio frequency (RF) transistors for 5G applications, the use of GaAs-based sensors in consumer applications, and the progress being made in InP-based optoelectronics for next-generation optical communication systems.
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Silicon Carbide News
Nexperia and Mitsubishi Electric Join Forces for Discrete SiC MOSFETs
Nexperia announced that it has entered into a strategic partnership with Mitsubishi Electric to jointly develop SiC MOSFETs. Hereby, both companies respond to the rapidly growing demand for high-efficiency discrete power semiconductors.
Mitsubishi Electric has a proven reputation as an industry leader in the provision of reliable and high-performance SiC modules. These devices are employed in Japan’s acclaimed high-speed Shinkansen trains which are celebrated for their unsurpassed levels of efficiency, safety, and reliability.
With its European heritage and global customer base in sectors ranging from automotive and industrial to mobile and consumer applications, Nexperia is a leading expert in discrete device packaging.
Heraeus Acquires Stake in SiC Start-up Zadient
Heraeus has acquired a significant stake in the start-up company Zadient Technologies which specializes in the production of silicon carbide source material. Through the partnership, Heraeus intends to accelerate the company's growth and support Zadient's innovative approach with its own know-how.
Zadient is a start-up company with headquarters in Chambery, France, and another production facility near Leipzig, Germany. The company manufactures high-purity silicon carbide source material through the Chemical Vapor Deposition (CVD) process and also develops technologies for high-yield large-diameter crystal growth. Zadient’s mission is to help remove materials bottlenecks in the silicon carbide semiconductor value chain and accelerate the wide-spread adoption of this highly energy-efficient technology.
“We are very happy that we found a way to accelerate growth in the SiC market by combining the innovative ideas of the materials start-up Zadient with the manufacturing and technical expertise of the Heraeus Group,” said Steffen Metzger , member of the Heraeus Group Management Committee.
Mitsubishi Electric to Issue Green Bonds for a SiC Wafer Fab
Mitsubishi Electric announced that it will issue green bonds in December 2023 to raise funds of 50 billion Yen ($330 million) for the construction of a SiC power semiconductor plant and the enhancement of related production facilities that handle products capable of contributing to decarbonization.
In preparation for the issuance, Mitsubishi Electric has formulated a Green Bond Framework that specifies its policies regarding the use of proceeds, the process for project evaluation and selection, the management of proceeds, and reporting, as defined in the Green Bond Principles 2021 issued by the ICMA - International Capital Market Association (ICMA) and the Green Bond Guidelines 2022 issued by Japan’s Ministry of the Environment. The company’s Green Bond Framework has been evaluated by an independent third party, Rating and Investment Information, Inc. (R&I), and confirmed to be in compliance with the aforementioned principles and guidelines.
BYD Uses SiC in its 8-in-1 Electrification System
Benjamin Gergaud Pussat , Technology & Cost Analysts at Yole SystemPlus , made a teardown of 比亚迪 ’s 8-in-1 powertrain. It includes the BMS, VCU, inverter, PDU, OBC-DC/DC merged into one unit, and the gearbox/e-motor in another.
The overall system space is optimized, with components placed very close to each other, and sub-boards soldered perpendicular to the OBC/DC-DC power board. This involves the implantation of an efficient thermal management solution characterized by the use of SiC technology for both inverter and OBC-DC/DC MOSFETS, thermal pads placed over critical areas, an insulating sheet, and a water-cooling system.
Opening the system makes it clear that the Chinese OEM has adopted a self-sufficiency strategy, as most of the key power components have been identified as being manufactured or assembled by BYD (inverter SiC power module, output current sensor module, power relays, DC link capacitor…). This certainly helps the company to lead the total integration race.
Parasitic Inductance and Current Spreading of Paralleled SiC MOSFETs
Paralleling SiC MOSFETs in multichip power switches is a common way to achieve the required current rating in high-power converters. The parasitic inductances and the static and dynamic current imbalance of the paralleled MOSFETs are limiting the maximum current and switching speed of the devices.
This paper from researchers of FAU Erlangen-Nürnberg investigates the effect, that the number of paralleled chips has on the parasitic inductance and the current balancing using analytical impedance analysis of lumped elements in the frequency domain. The proposed calculation approach is applied to identify the main design-relevant parameters affecting the parasitic inductance and the layout-related current spreading. The results are verified with numerical parameter extractions and finite element analyses.
Andreas Apelsmeier , Martin Maerz , Parasitic Inductance and Current Spreading of Paralleled SiC MOSFETs Analyzed by Impedance Modelling, International Conference on Power Electronics, Machines and Drives, Bruessel, October 2023
Webinar: SiC Power Cycling & Bipolar Degradation
SiC power products may experience voltage degradation which stems from the stacking faults (SFs) growth, commonly known as bipolar degradation (BD). To properly evaluate the BD impact on the electric performance of devices, it is important to distinct it from other stress-related degradation, e.g., power metal or interconnects. This aspect has not yet been addressed, although the bipolar degradation mechanism is well understood.
In this colloquium which will also be streamed via Teams, Davood Momeni , Nexperia Germany, and Sibasish Laha , Fraunhofer IISB , will discuss a methodology by modifying the power cycling test PC(sec) to PC(msec) to systematically investigate the effect of bipolar degradation while controlling the impact of thermal degradation, and the role of degradation on actual devices.
Double-Sided Cooled Split-Phase SiC Power Module with Fuzz Button Interposer
Conventional single-sided cooled (SSC) wire-bonded power modules have limitations in utilizing the benefits offered by new generations of silicon carbide (SiC) devices due to higher parasitic inductance and heat dissipation issues. Planar, low-profile, and double-sided cooled (DSC) power modules are emerging in inverters of EV powertrains to address the limitations of conventional SSC modules. However, there is a reliability concern introduced by the rigid interconnection between the device chips and two substrates of the DSC power module.
In this article, researchers from Stony Brook University present the design and development of a DSC, 1200-V/150-A SiC half-bridge split-phase power module, where flexible, compressible pins called “fuzz buttons” are used in a low-profile PCB to realize die top-side connection. The simulation result shows a 45% reduction of thermomechanical stress at the interposer–dies interface with a total power loss of 1300 W (200-W/SiC MOSFET and 125-W/SiC Schottky diode).
Double-sided cooling helps reduce the maximum junction temperature of the dies by 26%, compared to single-sided cooling. Moreover, the vertical commutation loop and utilization of copper layer in PCB-based fuzz button retainer board help to achieve a power loop inductance as low as 1.51 nH. Using "fuzz buttons" also reduces the fabrication process and increases the manufacturability, as the fabrication does not require multiple soldering steps with different temperatures.
Asif Emon, Ph.D. , Yuxuan Wu , 李阳 , Abdul Basit Mirza , Shiyue Deng and Fang Luo , "A Double-Sided Cooled Split-Phase SiC Power Module With Fuzz Button Interposer," in IEEE Journal of Emerging and Selected Topics in Power Electronics, vol. 11, no. 5, pp. 4918-4928, Oct. 2023, doi: 10.1109/JESTPE.2023.3294932.
Wolfspeed WolfPACK power modules available with pre-applied thermal interface material
The Wolfspeed WolfPACK power module family is now available with the option for pre-applied 霍尼韦尔过程解决方案 PTM6000 Series thermal interface material (TIM). This can reduce assembly cost and complexity while improving reliability and performance. Compared to standard grease solutions, WolfPACK modules with pre-applied TIM can reduce the junction temperature by 40?K under the same conditions or increase current capability by 60% due to the reduction in thermal resistance.
Product Quality Engineer - SiC at Nexperia
1 年Thank you Ralf Higgelke for sharing our webinar details in your newsletter. It's a joy to read all the news in a nutshell ??????
Thank you for sharing our webinar in this newsletter Ralf Higgelke. Appreciate your effort in creating this valuable source of weekly highlights.
Chief Marketing and Communications Officer - Technology Evangelist
1 年Thanks Ralf - Always a pleasure to read through your weekly business overview! ??
Lead Engineer Power Electronics at Eaton Research Labs
1 年Asif Emon, Ph.D.
Semiconductor market intelligence analyst - strategy & investment
1 年Thanks Ralf Higgelke for sharing