Short Course Program
GaN based materials and devices for power applications
Jian-Jang Huang received the B.S. degree in Electrical Engineering (EE) and the M.S. degree in Graduate Institute of Photonics and Optoelectronics (GIPO) from National Taiwan University (NTU), Taipei, Taiwan, in 1994 and 1996, respectively, and the Ph.D. degree in Electrical Engineering from the University of Illinois, Urbana-Champaign, in 2002.
He is now the chairman of GIPO NTU and the director of Innovative Photonics Advanced Research Center, NTU. His research interest is mainly on compound semiconductor electronics and optoelectronics. He was the chair of SPIE (San Diego, CA, USA), Optics & Photonics, International Conference on Solid State Lighting from 2011~2015, and the executive secretary of Taiwan Photonic Society from 2013 to 2016. He has been involved in several industrial and venture positions, including the board director of Unity Opto in Taiwan (2019~2020), Global Communication Semiconductor, Inc. in CA, USA (2011~2019), Tacbright Optronics Corp. in Taiwan (2013~2016) and TMP co. in Taiwan (2012~2013). In academia, he currently serves as the Editor of IEEE, Transactions on Electron Devices, the Associate Editor of IEEE, Transactions on Nanotechnology. He is a fellow of SPIE and OSA.
Nitride based high electron mobility transistors (HEMTs) and schottky barrier diodes (SBDs) have now reached a stage for commercialization in power electronics. They can be operated at high voltage, high current, high temperature and high switching speed. Their circuit conversion efficiency in the power module can be larger than Si devices and the corresponding passive components can be ten times smaller. In the modern era that energy consumption is a critical issue worldwide, the benefit of adopting GaN for power applications is very obvious.
In this tutorial talk, I will first show market profiles of nitride based electronics for power applications. The epistructure of HEMTs and SBDs will then be introduced by looking into it’s unique material growth method and 2DEG carrier accumulation mechanism. Physical properties such as the effect of piezoelectric and spontaneous polarizations in the Wurzite GaN crystal structure will be elaborated. I will next show principles of HEMT and SBD device operations, along with comparisons of technologies to improvement electrical performance. Challenges, such as current collapse and defect issues, and the corresponding solutions will be introduced. Finally, because AlGaN/GaN HEMTs are intrinsically normally on devices (D-mode (depletion mode)), which aren’t preferred for power electronics, I will discuss methods of achieving E-mode (enhancement mode) HEMTs.