Pushing the limits of high power devices with wide band gap materials
Event details
| Date | 29.01.2014 |
| Hour | 15:00 |
| Speaker |
Dr. Farid Medjdoub, IEMN, Lille Bio: Farid Medjdoub is a CNRS senior scientist at IEMN in France. He is affiliated with the Department of Circuit and System. He received his MS and PhD degrees in Electrical Engineering from the University of Lille in France in 2001 and 2004, respectively. In 2005, Farid Medjdoub joined the University of Ulm in Germany as a Research Associate. There, he was leading a successful European project targeting the development of new transistors based on a novel InAlN/GaN heterostructure paving the way for high power applications at millimeter wave frequencies. Following this work this heterostructure has been adopted worldwide. In 2008, he joined IMEC, a world-leading research center in nano-electronics and nano-technology as a senior scientist on GaN power devices. He developed innovative normally-off (In)AlN/GaN power transistors for high voltage applications and was leading the effort on reliability assessment of state-of-the-art L-band GaN-on-Si devices within a European project. Then, in 2010 he has been recruited by the National French Research Center (CNRS) in France and continued his effort on GaN devices as seen from the state-the-of-art devices achieved recently. Farid Medjdoub´s research interests include the design, processing and characterization of new electronic devices based on wide band gap semiconductors for millimeter-wave power amplification and low noise applications as well as for high power conversion. He is particularly interested in the development of new concepts based on the unique properties of nitrides semiconductors. He is author or co-author of more than 100 scientific papers in international journals and conferences, three book chapters, multiple invited talks and 4 patents. He is a regular reviewer for IEEE journals and expert member of the French Micro- and Nanotechnology observatory. He is also a TPC member of the novel IEEE international conference Wide Band Gap Power Devices and Applications (WIPDA) held yearly in the US. |
| Location | |
| Category | Conferences - Seminars |
Wide band gap (WBG) semiconductors enable devices to operate at much higher temperatures, voltages, and frequencies making the power electronic modules using these materials significantly more powerful and energy efficient than those made from conventional semiconductor materials. Thus, WBG devices are expected to pave the way for exciting innovations in both RF and power electronics.
In particular, Gallium Nitride (GaN) devices are foreseen as the next generation of RF power transistor in the millimeter wave range. In this frame, we developed an innovative technology based on AlN/GaN/AlGaN double heterostructure grown on silicon substrate. The aim is to realize robust and cost-effective circuits in the Ka band and beyond that would pave the way to a European source of reliable millimeter wave MMIC GaN-on-Silicon circuit telecommunication and radar systems.
Furthermore, as an alternative to Silicon devices, GaN power switching devices are emerging as an attractive candidate to support the next generation of full electric vehicles as well as to renewable energy systems. Indeed, a power switching device is one of the key components that determines the performance of such systems. Presently, Silicon insulated gate bipolar transistors (Si-IGBTs) are typically used in the converters and inverters. However, Si devices have attained technological maturity and have a limitation of performances due to their material limits. They have high on-resistance leading to large conduction losses, low switching frequency meaning larger capacitors and inductors are required for filtering and they cease to function beyond 150°C and so require cooling. Next generation of power switch devices need to be more efficient, lighter and deliver high power (> 100kW) with high power source voltage (> 600V) for increased driving range. This can be addressed by using GaN material grown on Silicon owing to its intrinsic properties. However, there are still challenges to be overcome for 600 V GaN devices before commercialization such as the dynamic on-resistance degradation which involves the control of the passivation, the gate dielectric deposition, the growth and processing quality etc. Normally-off GaN device operation is also required while this type of device operates inherently in normally-on (i.e. negative threshold voltage) conditions. We are developing several solutions to overcome this issue. Finally, in longer term, power electronic applications around 1 kilovolt could also be impacted by the emerging GaN-on-Si devices. Today, the breakdown voltage (VBK) of these devices is limited to around 1.5 kilovolts. We have determined that the main limitation of VBK was the silicon substrate as the electric field crosses the entire GaN heterostructure that has a total thickness limited by strain issues. We are developing a disruptive technology that should significantly enhance the VBK of GaN-on-Si devices beyond 3 kilovolts based on the local silicon substrate removal.
In this talk, I will describe the origin, the history and the prospect of this specific GaN technology that could create a real breakthrough for power electronic applications from DC up to the millimeter wave range.
In particular, Gallium Nitride (GaN) devices are foreseen as the next generation of RF power transistor in the millimeter wave range. In this frame, we developed an innovative technology based on AlN/GaN/AlGaN double heterostructure grown on silicon substrate. The aim is to realize robust and cost-effective circuits in the Ka band and beyond that would pave the way to a European source of reliable millimeter wave MMIC GaN-on-Silicon circuit telecommunication and radar systems.
Furthermore, as an alternative to Silicon devices, GaN power switching devices are emerging as an attractive candidate to support the next generation of full electric vehicles as well as to renewable energy systems. Indeed, a power switching device is one of the key components that determines the performance of such systems. Presently, Silicon insulated gate bipolar transistors (Si-IGBTs) are typically used in the converters and inverters. However, Si devices have attained technological maturity and have a limitation of performances due to their material limits. They have high on-resistance leading to large conduction losses, low switching frequency meaning larger capacitors and inductors are required for filtering and they cease to function beyond 150°C and so require cooling. Next generation of power switch devices need to be more efficient, lighter and deliver high power (> 100kW) with high power source voltage (> 600V) for increased driving range. This can be addressed by using GaN material grown on Silicon owing to its intrinsic properties. However, there are still challenges to be overcome for 600 V GaN devices before commercialization such as the dynamic on-resistance degradation which involves the control of the passivation, the gate dielectric deposition, the growth and processing quality etc. Normally-off GaN device operation is also required while this type of device operates inherently in normally-on (i.e. negative threshold voltage) conditions. We are developing several solutions to overcome this issue. Finally, in longer term, power electronic applications around 1 kilovolt could also be impacted by the emerging GaN-on-Si devices. Today, the breakdown voltage (VBK) of these devices is limited to around 1.5 kilovolts. We have determined that the main limitation of VBK was the silicon substrate as the electric field crosses the entire GaN heterostructure that has a total thickness limited by strain issues. We are developing a disruptive technology that should significantly enhance the VBK of GaN-on-Si devices beyond 3 kilovolts based on the local silicon substrate removal.
In this talk, I will describe the origin, the history and the prospect of this specific GaN technology that could create a real breakthrough for power electronic applications from DC up to the millimeter wave range.
Practical information
- General public
- Free
Organizer
- Prof. De Micheli
Contact
- Sylvie Moreau