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        COLLOQUIUM OF THE COMPUTATIONAL MATERIALS SCIENCE CENTER
                   School of Computational Sciences
                           (CSI 898-Sec 001)
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       Ultrafast Microwave Annealing of Ion-implanted SiC and the 
   High-frequency Power Output Performance of GaN/AlGaN HEMT Devices

                         Mulpuri V. Rao
Department of Electrical and Computer Engineering, George Mason University

A high annealing temperature, a short annealing duration, and high heating and
cooling rates are key requirements  of ahieving optimum electrical
characteristics and surface morphology in ion-implantation doped SiC.
Solid-state microwave annealing facilitates all these requirements for implant
activation in SiC.

In this work, ultra-fast solid-state microwave annealing has been performed,
for the first time, on N+-, Al+-, and B+-implanted SiC. The solid-state
microwave system used in this study is capable of raising the SiC sample
temperatures to extremely high values, at heating rates exceeding 400 C/s.
Surface RMS roughness is ~ 2 nm even for annealing at 1850 C for 35 s.
Elevated temperature (700 C), Al-implanted SiC has an unprecedented low
sheet resistance of 7 kilo-ohms upon annealing at 1850 C / 35 s. For the
elevated temperature (700 C) N- implantations, the RT carrier activation is
36.2 % for a sheet resistance of 407 ohms, after 1600 C/10 s annealing.   

At present, GaAs/AlGaAs HEMT devices are one of the highly used
devices for for high-power high-frequency amplification application. We have
evaluated the power output performance of non-optimum GaN/AlGaN HEMT devices
against the performance of state-of-the-art GaAs/AlGaAs HEMT devices for
different output power configurations. Even non-optimum GaN devices showed
similar power output performance compared to the state-of-the-art GaAs/AlGaAs
devices.
                        April 24, 4:30 pm
               Room 206, Science & Tech. I, Fairfax Campus

Refreshments will be served at 4:15 PM.
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Find the schedule at http://www.cmasc.gmu.edu/seminar/schedule.html
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