Keynote speakers
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Research and Development of SiC Power Semiconductor Devices Hiroyuki Matsunami, Ph.D. Emeritus Professor, Kyoto University, Japan |
Short biography:
Hiroyuki Matsunami received the B.E., M.E., and Ph.D. degrees from Kyoto University, Kyoto, Japan, in 1962, 1964, and 1970, respectively. He has been with Kyoto University as a Research Associate since 1964, as an Associate Professor since 1971, and as a Professor since 1983. Since April 2003, he has been an Emeritus Professor of Kyoto University. He is currently the Director of Innovation Plaza Kyoto, Japan Science and Technology Agency. He was a Visiting Associate Professor with North Carolina State University, Raleigh, from 1976 to 1977. His professional work is on semiconductor science and engineering. He has also been working on semiconductor material synthesis, characterization, and device demonstration. He began his work on semiconductor SiC in 1968. He has worked on blue light-emitting diodes of SiC, heteroepitaxial growth of SiC on Si, and homoepitaxial growth of SiC on SiC substrates. He has greatly contributed to the progress in SiC devices by bringing high-quality epitaxial layers grown by the concept of step-controlled epitaxy, high-performance Schottky barrier diodes, and high-channel electron mobility in SiC MOSFETs. Dr. Matsunami is a Fellow of Engineers and a member of the Institute of Electrical Engineers of Japan, the Japan Society of Applied Physics, and the Japanese Association of Crystal Growth. He is the recipient of the Outstanding Research Award from the Ministry of Education, the Japan Society of Applied Physics, and the Institute of Electronics, Information, and Communication.
Abstract:
Silicon carbide (SiC) power devices have been in production for over 20 years, and have shown higher performance such as low-loss, high switching speed, high-temperature operation and simple cooling system compared to ordinary Silicon (Si) power devices. In this presentation, after the importance of effective electric energy use and expectation for SiC power devices are described, fundamental researches in Kyoto University started from 1968 are given. Present-day SiC technologies including SiC wafers and power devices are explained. National projects for practical implementation of SiC power devices into society are shown. We will discuss some remaining issues to contribute for the reduction of “Global Warming” using SiC power devices.
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Canceled. No show. Yong Kang, Ph.D. Huazhong University of Science and Technology, China |
Short biography:
Prof. Yong Kang was born in 1965. He received a B.S. degree and Ph.D. degrees in Power Electronics and Electric Drive in 1998 and 1994, respectively, from Huazhong University of Science and Technology (HUST). In 1994, he joined the HUST as an assistant professor and became an associate professor and full professor in 1996 and 1998, respectively. He had been the Dean of School of Electric and Electronics of HUST from 2008 to 2016. During that time, he helped to establish a State Key Lab of Advanced Electromagnetic Engineering and Technology.
His early research interests focus on performance improvement methods such as modeling, digital control, modular operation, and EMI suppression for various converters. His main research interest has moved to packaging and integration methods for high power density converter based on emerging wide bandgap devices in recent ten years. He established an Advanced Semiconductor, Packaging and Integration Lab in HUST, which has a 370 square meters clean room, well-equipped with new semiconductor material growing, WBG semiconductor fabrication, packaging, integration, and converter testing.
He has published more than 300 papers in IEEE transactions and conference and is co-author of two Chinese books. He holds dozens of domestic and international patents, and served in some Chinese and international technical committees. He is a senior member of IEEE.
Abstract:
High voltage and high switching frequency SiC devices start to attract attention for HEV/EV applications. This talk introduces a high efficiency, high power density, and lightweight motor drive inverter using a highly integrated and low profile 1200V double-sided cooling SiC power module. Compared with the traditional design method, a module-level started multi-objective optimization design method is proposed. A novel double-sided low thermal resistance and low inductance double-sided cooling SiC power module is developed. A more than 100 kW/L 45kW three-phase inverter is tested under 800V DC-link voltage and high switching frequency.
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Innovative development trends of SiC power products in mass production Chwan Ying Lee, Ph.D. President, Hestia-Power Group, Taiwan |
Short biography:
Dr. Lee received the B.S. and Ph.D. in material science & engineering from the University of National Cheng Kung University (NCKU) Taiwan, in 1990 & 1995, respectively. He immediately joined Industrial Technology Research Institute (ITRI), engaged in the design and process development of high-frequency and high-voltage device. Then he joined two companies in HsinChu Science Park, Taiwan since 1999, and took responsibility for LCD driver, high-voltage IC process, Power DMOS process, flat-cell device, high-frequency SiGe BiCMOS device and other silicon-based semiconductor devices and design technologies for 18 years. In 2013, he founded Hestia-Power Inc. (HPI) and focused on product development of wide-band gap material. He is now the CEO of HPI. and leading the team to engage in innovative SiC technology and novel application in EV cars and renewable energy. He co-authored more than 60 technical presentations and publications and hold more than 80 patents in the fields of high-frequency, ESD and SiC-related high-voltage devices.
Abstract:
SiC devices are undergoing disruptive innovation and creating more novel applications, especially in the fields of EV cars and renewable energy applications. A scalable structure was used to implement the SiC MOSFET with integrated junction barrier controlled Schottky diode (JMOS) without area penalty. The JMOS was proven to have a lot of benefits including static, dynamic performance and could avoid the bipolar degradation phenomenon compared to standard DMOS, thus it is highly suitable for discrete and power module in EV applications. We also successfully integrated back-to-back SiC Zener diode into gate terminal of a SiC DMOS monolithically. This concept is designed and manufactured as an asymmetric bidirectional voltage-clamp between the gate and source to protect the gate oxide of SiC MOSFET from the overvoltage stress. In addition, a Photovoltaic controlled MOSFET relay (PhotoMOS) with fast turn on/off Speed and high I/O Galvanic Isolation Rating is also developed with our partner to replace mechanical relays and may also be used in EV car. We also successfully manufactured 3.3 KV SiC MOSFETs with an innovative termination structure and will introduce this technology in this paper.
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Research activities to maximise the capability of new power devices Ken Nakahara, Ph.D. General Manager of Research and Development Center, ROHM Co. Ltd, Japan |
Short biography:
Ken Nakahara received the B.S.degree in physics from Kyoto University, Kyoto, Japan, in 1995, and joined ROHM CO.,LTD. He researched light-emitting device and materials and the Ph.D. degree of science in chemical from Tohoku University,Sendai,Japan,in 2010. He is now the general manager of the Research and Development Center of ROHM.
- [1] H. Sakairi et al, IEEE Trans. Power. Elec. 33,7314 (2018)7314; Y. Nakamura et al., IEEE Trans. Power. Elec. 35, 2950 (2020).
- [2] Y. Nakakohara et al., IEEE Indust. Elec. 63,2103 (2016); T. Miyazaki et al., IEEE Indust. Elec. 65, 9429 (2018); J. Kashiwagi et al., IEEE Trans. Circuits. Systems. II 66, 101 (2019).
Abstract:
The social demands to use electricity more efficiently require the excellent capability of wide-bandgap (WBG) semiconductor power devices (PD), but the users of the devices need solutions to solve the issues they are confronting, not the characteristics of the devices only from device-engineers’ viewpoints. New things improve something, but unavoidably and often create new issues to be solved at the same time. Therefore the comprehensive research on "how to use new PDs appropriately" are inevitable to fledge fully the features of WBGPDs. Our research activities have been planned and made from this point of view. The contents of this presentation ranges from our new generation of silicon carbide metal-oxide-semiconductor transistors and newly developed power modules through the related simulations and measurements [1] to the demonstration of power supplies improving their performance by applying WBG PDs. [2]
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Rapid Prototyping for SiC Electronics Alan Montooth, Ph.D. IEEE Fellow, Past President of IEEE Power Electronics Society, Distinguished Professor, The Twenty-First Century Research Leadership Chair, Department of Electrical Engineering, University of Arkansas, USA |
Short biography:
Alan Mantooth received the B.S. and M.S. degrees in electrical engineering from the University of Arkansas, Fayetteville, AR, USA, in 1985 and 1987, respectively, and the Ph.D. degree from the Georgia Institute of Technol- ogy, Atlanta, GA, USA, in 1990.
He was with Analogy, Portland, OR, USA, where his research work was focused on semiconductor device modeling and the research and development of modeling tools and techniques. In 1998, as a Faculty Member, he joined the Department of Electrical Engineering, University of Arkansas, where he is currently a Distinguished Professor. His current research interests include analog and mixed-signal integrated circuit design and computer-aided design, semiconductor device modeling, power electronics, and power electronic packaging.
Dr. Mantooth is a Member of TauBeta Pi and Eta Kappa Nu, and a Registered Professional Engineer in Arkansas. He helped establish the National Center for Reliable Electric Power Transmission (NCREPT), University of Arkansas, in 2005. He serves as the Executive Director for NCREPT as well as two of its centers of excellence: the NSF Industry/University Cooperative Research Center on Grid-Connected Advanced Power Electronic Systems, and the Cybersecurity Center on Secure, Evolvable Energy Delivery Systems funded by the U.S. Department of Energy. In 2015, he also helped to establish the University of Arkansas’s first NSF Engineering Research Center, Power Optimization for Electro-Thermal Systems, which focuses on high power density systems for transportation applications. He holds the 21st Century Research Leadership Chair in Engineering. He serves as an Immediate Past-President for the IEEE Power Electronics Society from 2019 to 2020.
Abstract:
As the field of wide bandgap power semiconductor devices continues to emerge, an entire technology ecosystem is developing both around and independent of power electronics. As an example, SiC integrated circuitry has been demonstrated to provide enhanced performance possibilities around the power device technology when integrated within power modules. However, SiC sensors represent an entirely different field of endeavor in many cases. As wafer sizes grow and material quality continues to improve, SiC offers opportunities that silicon cannot match in some applications. Unfortunately, the research and development ecosystem surrounding SiC is limited, and thus the field is unable to grow as rapidly as it could. This talk with describe some of those choke points and how efforts are underway to open up the rapid prototyping capabilities in SiC electronics relating to fabrication and packaging.
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Development of SiC devices and their applications Takeshi Oi Chief Engineer, Advanced Technology R&D Center, Mitsubishi Electric Corporation, Japan |
Short biography:
Takeshi Oi received M.S. degrees in engineering science from Kyushu University in 1988. He joined Mitsubishi Electric Corporation in 1988. From 2002 to 2014, he was engaged in Advanced Technology R&D Center for managing the research and development of Si and SiC power modules and their application technologies. During this period, he developed power electronics equipment using SiC devices as well as Si devices with his coworkers. As an example, railcar traction inverters for DC 1,500V catenaries with 3.3kV full SiC power modules were launched in 2013. He is currently chief engineer in Power Electronics Technology Laboratory.
Abstract:
SiC devices have been expected as the key devices for significant improvements of the power electronics systems and the practical use of them began. In this presentation, technologies for SiC devices and SiC power converters in Mitsubishi Electric will be introduced. Thanks for SiC device properties, substantial energy saving performance in the photovoltaic inverters and the railcar power converters could be obtained. In the railcar power converters, significant size and weight reduction could also be achieved. SiC based modular multilevel cascade converters (MMCCs) for HVDC transmission systems will also be explained. More than 50% semiconductor loss reduction compared to Si devices was achieved.
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Reliability of GaN power transistors Kenichiro Tanaka, Ph.D. Energy Solutions Development Center, Engineering Division, Industrial Solutions Company, Panasonic Corporation, Japan |
Short biography:
Dr. Kenichiro Tanaka received the bachelor, the master and the doctor degree of Engineering from the University of Tokyo in 1997, 1999, and 2003, respectively. After he had investigated as a Special Postdoctoral Researcher in RIKEN institute, Japan, he joined Semiconductor Device Research Center, Matsushita Electronics Corporation (currently Panasonic), Kyoto, Japan in 2007. Since then, he has been engaging in the development of GaN power transistors applicable for high-frequency switching applications. He started his career with the development of crystal growth of GaN on Si substrate, and he has been involving the device design, manufacturing, reliability, and simulation study. He had involved in MHz high-frequency power converter design employing Panasonic’s GaN transistors in CPES, Virginia Tech, in the USA from 2015 to 2017. He authored and coauthored 34 technical papers. He is a member of Japanese Journal of Applied Physics and was a sub-committee member of International Reliability Physics Symposium (IRPS) in 2017 and 2018.
Abstract:
In recent years, as GaN power transistors come into widespread use as the promising switches for power converter applications, it is all the more important and inevitable to guarantee their reliability.
Firstly, we review how we strengthen robustness of GaN power transistors. Most notable technique is a Hybrid-Drain-embedded Gate Injection Transistor, whose structure is quite effective to ensure the GaN reliability to commercially-applicable level.
Secondly, we discuss how to evaluate the robustness of GaN power transistors. The robustness of GaN power transistors should be examined not only under switching operations but also the conventional DC tests standardized for Si power transistors. This is because severe switching event induces the so-called current collapse, which end up in device degradation. Since the magnitude of current collapse depends strongly on the IDS-VDS trajectory during the switching event, the concept of Switching Safe Operating Area (SSOA) is proposed to define the IDS-VDS limit wherein the device can be switched with safety. We exemplify the SSOA for our HD-GIT under several switching conditions. We hope that the methodology presented here is utilized to guarantee the robustness of GaN power transistors and thus accelerates the more widespread use of GaN power transistors.
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General Formula of SEB Failure Rate Calculation for Power Device Ichiro Omura, Ph.D. Professor, Kyushu Institute of Technology, Japan |
Short biography:
Ichiro Omura received the M.S. degree (Mathematics) from Osaka University, Osaka, Japan, in 1987, and joined Toshiba Corporation. He received Dr. degree in engineering from ETH Zurich, Switzerland, in 2001. Since 2008, he has been with Kyushu Institute of Technology and since 2012 he is the Director of the Next Generation Power Electronics Research Center in Kyushu Institute of Technology.
Abstract:
Electric power requirement in aircraft and spacecraft has been significantly increased through decades and it reached to one mega watt level in B787 and the International Space Station with bus voltage of 270V and 100V, respectively. As a result of this trend, the bus voltage need to be increased to reduce wire frame weight.
High bus voltage, on the other hand, increase the risk of Single Event Burnout (SEB) by the increased flux of high energy particle at high altitude. SEB failure rate of high voltage power device has been discussed in terrestrial level since 1994 (ISPSD'94 papers), which forced to change N-base design of high voltage device. Unfortunately, the models proposed for terrestrial SEB are not applicable to aircraft or spacecraft application since particle flux distribution is completely different.
This paper explains newly proposed SEB failure rate calculation method for power devices in space and aviation applications based on TCAD simulation and particle induced charge deposition probability model. In the proposed method, SEB cross section is obtained and then the failure rate is calculated from the cross section and flux distribution for energy at the altitude the device is used.
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The path forwar for GaN Power Devices Alexander Lidow, Ph.D. CEO and Co-founder of Efficient Power Conversion Corporation (EPC), USA |
Short biography:
Alex Lidow is CEO and co-founder of Efficient Power Conversion Corporation (EPC). Since 1977, Dr. Lidow has dedicated to making power conversion more efficient with the belief that this will reduce the harm to our environment and increase the global standard of living.
Prior to founding EPC, Dr. Lidow was CEO of International Rectifier Corporation. A co-inventor of the HEXFET power MOSFET, Dr. Lidow holds many patents in power semiconductor technology and has authored numerous publications on related subjects, including industry’s first textbook on GaN power transistors – GaN Transistors for Efficient Power Conversion (2012, Wiley), with its latest updated 3rd Edition being published in October 2019.
He has authored numerous peer reviewed publications on related subjects, and received the 2015 SEMI Award for North America for the commercialization of more efficient power devices. Dr. Lidow was one of the lead representatives of the Semiconductor Industry Association (SIA) for the trade negotiations that resulted in the U.S. - Japan Trade Accord of 1986 and testified to Congress on multiple occasions on behalf of the industry.
Dr. Lidow has been inducted into the IEEE International Symposium on Power Semiconductor Devices and ICs (ISPSD) Hall of Fame 2019 in May 2019 for his contributions to advancing power semiconductor technology.
Dr. Lidow holds degrees from Caltech and Stanford. He received his Bachelor of Science in Applied Physics from Caltech in 1975, and a Ph.D. in Applied Physics from Stanford University in 1977 as a Hertz Foundation Fellow.
Abstract:
GaN power devices, discrete transistors and integrated circuits, have been in production for over 10 years and have made significant inroads in many applications that benefit from the smaller size and the faster switching speed of power devices. These devices are several times smaller than their aging silicon MOSFET ancestors and, largely as a result of this size advantage, have also become comparatively less costly to produce. Now that the gap has opened in both performance and cost, what are the new frontiers for GaN technology that will both enable new applications and materially improve existing applications? In this presentation, we will discuss cost, power density, and integration challenges facing GaN producers. We will attempt to quantify the impact and set a reasonable timetable for implementation.
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Overview of diode-less SiC power module technology for high power density - devices and materials Akio Shima, Ph.D. Chief Researcher of Center for Technology Innovation-Electronics, Hitachi, Ltd. Research & Development Group, Japan |
Short biography:
Dr. Shima joined Hitachi, Ltd in 1995. Since then, he has been working on researches of Si LSI devices and Si IGBT power devices. In 2000-2002, he was a visiting researcher, Stanford University, Center for Integrated Systems, where he focused on the TCAD modeling of various devices.
Dr. Shima started researches of SiC in 2009. He is now Senior Chief Researcher, Center for Technology Innovation-Measurement & Electronics, Research & Development Group, Hitachi, Ltd., responsible for research activities on Energy Conversion Electronics including SiC material science, power devices and its industrial application. Concurrently Dr. Shima is serving as a specially-appointed professor, International Center of Advanced Energy Systems for Sustainability, Tokyo Institute of Technology where he is engaged in researches of Energy Management Components and Systems with some facilities. He is a member of the IEEE and the IEE of Japan and member of the Japan Society of Applied Physics.
Abstract:
A 3.3 kV ultra-high power density SiC power module was developed by constituting the module with only SiC-MOSFETs. The low-loss and high reliability characteristics of the module are demonstrated. However, a well-known issue exists when using body diodes of SiC-MOSFET: “bipolar degradation”. Bipolar operation of the body diode leads to stacking fault expansion from pre-existing basal plane dislocations by electron-hole recombination. The stacking faults increase not only the Vf of the body diode, but also the on-resistance of the channel conduction. This bipolar degradation is serious especially in the 3.3 kV class. Because the low doping density of the epi-layer and long hole-lifetime. Additionally, the thick epilayer results in large stacking fault. As a countermeasure for“bipolar degradation” issues, we also deployed new high-throughput screening process technolog
Furthermore in this presentation, we will review the physics of bipolar degradation. As a method to analyze, Operando X-ray topography analysis was developed during the application of the forward current stress to the body diode in the SiC MOSFET, The sequence of the SF expansions into the SiC epitaxial layer can be observed in X-ray topographies at 1-second time resolution, which is enough to analyze the origin and velocity of the SF expansion phenomena. In this method, we can change the condition of the forward stress on the body diode while observing the X-ray topography. This is an important tool to clarify the physics of defect physics.