Monte Carlo Simulations of Electron Transport in In0 52Al0 48As/In0 75Ga0 25As High Electron Mobility Transistors at 300 and 16K

We performed two dimensional Monte Carlo (MC) simulations of 200 nm gate InP based In0 52Al0 48As/In0 75Ga0 25As pseudomorphic high electron mobility transistors (HEMTs) at 300 and 16 K to clarify the effect of temperature or electron transport On decreasing the temperature the calculated maximum transconductance g(m) increases from 1110 mS/mm at 300 K to 1400 mS/mm at 16 K On the other hand the calculated cutoff frequency f(T) increased from 168 GHz at 300 K to 223 GHz at 16 K The electron velocity overshoot under the gate is enhanced by reducing the temperature The resulting average electron velocity under the gate increases from 3 60 x 10(7)cm/s at 300 K to 5 26 x 10(7) cm/s at 16 K The average velocity of the electrons and electron occupancy in each valley were calculated to clarify the trend of the electron velocity with temperature. We found that the intervalley phonon scattering as well as the intravalley scattering plays a very important role in determining the average electron velocity at 300 K The contribution of the intervalley scattering to the average electron velocity is almost of the same degree as that of the intravalley scattering at 300 K (C) 2010 The Japan Society of Applied Physics