Two-dimensional device simulation for radio frequency performance of AlGaN/GaN HEMT

In order to obtain better high frequency performance for GaN-based devices, we investigate the influence of the gate length L
g
, the gate-source space L
gs
, the gate-drain space L
gd
, and the thickness of barrier AlGaN on frequency performance of AlGaN/GaN high electron mobility transistors (HEMTs) using silvaco TCAD simulation. Besides, the importance of Ohmic contact resistance R
c
to current-gain cutoff frequency f
T
is also presented by our simulation. It presents that the f
T
increases dramatically with the decrease of L
g
and R
c
while L
gd
and L
gs
affect f
T
lightly. Meanwhile, the optimized thickness of AlGaN barrier layer is obtained in our structure.