Meeting Locations and Directions

Burgess Award Lecture
The Promise of GaN and Related Compounds for Future Electronics
Professor Aris Christou
2007 ASM-DC George Kimball Burgess Memorial Award Winner
Department of Materials Science & Engineering
University of Maryland

Dates:  April 22, 2008
Time:   6:00 pm - Social, 6:30 pm - Dinner, 7:30 pm - Announcements, 7:45 pm - Dessert and Coffee, 8:00 pm - Presentation
Place:  Pines of Rome restaurant, Bethesda, MD (see meeting locations link above)
RSVP:  by April 21, 2008 to Theresa Valentine Clark, chair@asm-dc.org.
Cost:  $20 for dinner, NOT including beverages. Students pay only $10!

Abstract:
GaN-based microwave power HEMTs and power FETs are mostly grown on SiC, sapphire and Si and have defined the state-of-the art for output power density and have the potential to replace GaAs-based transistors for a number of high-power applications. Output power densities at microwave frequencies of GaN based HEMTs on both sapphire and SiC substrates have improved from 1.1 W/mm in 1992 to 9.2 W/mm at the beginning of 21st century. The GaN-based material system, consisting of GaN, AlN, InN and their alloys, has become the basis of an advanced, microwave-power-device technology for a number of reasons. GaN has a breakdown field that is estimated to be 3 MV/cm, which is ten times larger than that of GaAs (although temperature in GaN HEFTs are also very high), and a high peak electron velocity of 2.7x107 cm/s. In addition, this material system is capable of supporting a heterostructure device technology with a high two-dimensional electron gas (2-DEG) carrier density and mobility. As a result of these properties, excellent high-frequency, high-power performance has been achieved with GaN-based HEMTs. Although significant progress has been made in the past few years, additional developmental work is required for GaN low-noise, high-frequency (power HEMTs) and high-power microwave (power HFETs) to become a viable technology. This presentation reviews the recent results at UMD in determining the fundamental limitations to GaN HFET performance from a defect structure point of view.

Biography:
Professor Aris Christou was the Chairman of the University of Maryland's Materials and Nuclear Engineering Department until July 2003, and presently holds professorial appointments in the Department of Materials Science and Engineering and Mechanical Engineering. Prof. Christou received his Ph.D. in Materials Science from the University of Pennsylvania in 1971. He presently conducts research in compound semiconductor materials and process science, radiation effects in materials and devices, manufacturing science, and reliability. Dr. Christou was previously a Professor of Electronic Materials at Rutgers University, and research scientist at the Naval Research Laboratory. He has authored two books and has been the editor of three others. Dr. Christou has more than 150 publications in archival journals and 14 patents (including two pending), and has organized international conferences in GaAs devices, materials and reliability. Dr. Christou is a Fellow of the IEEE, a Fullbright Fellow, a recipient of the DoD-Berman Publication Awards, and an IEEE Guest Lecturer.

Professor Christou’s technical contributions encompass the development of materials surface and interface science and methodologies for achieving reliable high frequency devices, optoelectronic devices and circuits. Professor Christou’s contributions established the critical relationships which exist between materials, materials surfaces and interfaces, process science, and reliability.