edc@mail.nctu.edu.tw

http://csdlab.mse.nctu.edu.tw

408, Microelectron and Information Research Center,

Dept. Materials Science and Engineering,

Title : Realization of GaN-Based Technology for High Power and High Power Applications

Abstract 

Wide band gap semiconductor of GaN and its related materials are promising for future power and high frequency applications. In particular, the GaN high electron mobility transistor (HEMT) grown on large-size Si substrate is suitable for low-lost and high power switching applications. The GaN HEMT could be fabricated into convertors and invertors for electrified vehicle (EV). In order to achieve GaN HEMT device with high efficiency, various issues have to be considered. These include the careful design of material structure and device layout. Furthermore, surface passivation techniques are critical for reducing dynamic on-resistance (R_on) and improving reliability. For safety purpose, a normally-off device is required. Thus, the pros and cons of normally-off device fabrication approaches such as gate-recessed, p-GaN cap and F-plasma treatment will be discussed. The possibility of using fully-copper-based metallization will also be addressed.The copper metallization can reduce the fabrication cost effectively by replacing the conventional gold metallization. Finally, power module is demonstrated by employing the GaN HEMTs and Schottky barrier diodes.

For future RF power application, GaN HEMTs on SiC substrate are fabricated. The GaN material grown on SiC can achieve better crystal quality andthe HEMT devices arealso beneficial from better thermal dissipation due to high thermal conductivity SiC substrate. GaN HEMT on SiC could be used in future high frequency applications such as formilitary phased array radar and civilian 4^th-generation base station. Besides the AlGaN/GaN HEMT structure, new material structures such as InAlN/GaN and AlN/GaN are also demonstrated. These structures have great potential for very high frequency (>300 GHz) and high power applications.

Biography

Prof. Dr. Edward Y. Chang received his B.S. degree from Materials Science and Engineering, National Tsing Hua University, Hsinchu, Taiwan in 1977, and his Ph.D. degree from Materials Science and Engineering, University of Minnesota Minneapolis, MN in 1985.

                  Dr. Chang was with Unisys Corporation GaAs Component Group, Eagan, MN, 1985 to 1988 and Comsat Labs Microelectronic Group from 1988 to 1992. He worked on the GaAs MMIC programs on both groups. He joined National Chiao Tung University (NCTU), Hsinchu, Taiwan, in 1992. In 1994, he helped set up the first GaAs MMIC production line in Taiwan, and become president of Hexawave Inc., Hsinchu, Taiwan, in 1995. He returned to the teaching position at NCTU in 1999. Dr. Chang is currently the Dean of Research and Development and professor of the Department of Materials Science and Engineering and Dept of Elecrical Engineering at NCTU. He is also the director of Diamond Lab and the director of NCTU-TSMC research center.

            His research interests include new device and process technologies for Compound Semiconductors for wireless communication and high power electronic applications.. Dr. Chang is a senior member and a DL(Distinguished Lecturer) of the IEEE Electronic Device Society. Currently his research activities include InP, GaAs based compound materials and devices (HEMT, HBT) for wireless communication and sub-milimeterwave imaging applications. GaN based materials (MBE, MOCVD) and High frequency&High power electronic (HEMT) applications. III-V/ Si integration (Ge, SiGe, GaAs, InP) for logic applications. Advanced package (Flip chip) for high frequency and power applications.

                   Dr. Chang has received quite a few honors from Taiwan and abroad, including two times Outstanding. Research Award and Distinguished Contribution for Technical Transfer to Industry, both from National Science Council, Taiwan. National Award for Academic Contribution to Industry and Industry and Economy Contribution Award, both from Ministry of Economic Affairs, Taiwan. Distinguished Electrical Engineering Professor Award from Chinese Institute of Electrical Engineering. He is also Distinguished Lecturer of IEEE, Fellow of Taiwanese Materials Society, and Fellow of IEEE.