Biography: Dong Ji is currently working as an Assistant Professor in the Chinese University of Hong Kong, Shenzhen. Before he joined the faculty, he held a position of Silicon Architecture Engineer in Intel Santa Clara. He received his Ph.D. from the University of California Davis in 2017. His research work focuses on wide bandgap semiconductors, primarily on gallium nitride (GaN), for power, RF, and photonics applications. He served as the key researcher the “Strategies for Wide Bandgap, Inexpensive Transistors for Controlling High-Efficiency Systems” project supported by the US Department of Energy, delivering 1200V-class power switches based on GaN. He has authored/co-authored over 50 journal articles, conference proceedings, and book chapters. Dr. Ji received Anil Jain Memorial Prize for Best Dissertation from UC Davis, the Chinese Government Award for Outstanding Self-Financed Oversea Students from China Scholarship Council, the Fearless recognition award from Intel NSG, and the site recognition award from Intel Fab68.  

      Abstract: Silicon-based devices have served the semiconductor industry for more than 60 years. The device performances are approaching the fundamental material limits. Now with the continued emergence of advanced electronics systems, such as 5G, the internet of things, quantum computing, and electrical vehicles, silicon cannot fulfill the increasing requirements of high-efficiency and high-frequency. Now is the time to reshape the topic of electronic devices using more advanced semiconductors. Wide bandgap semiconductors, such as gallium nitride (GaN) and silicon carbide (SiC), have higher electron velocity, higher breakdown electric field strength, and higher operating temperature limit, all of which make them promising candidates in the upcoming era of greener electronics. In the past 20 years, GaN has shown excellent performances in solid-state lighting (blue LED), RF and power devices, where the GaN films are grown on foreign substrates, such as Si and sapphire. The foreign substrates reduce the cost significantly, however, they also impact the device performance and reliability. Since 2013, both governments and industry have invested heavily in GaN homogeneous growth techniques, making new device architectures and processes available. Most notably, vertical GaN power devices are being developed, which show great potential in power switches. In this talk, I will review the status of vertical GaN power technology.