Monte Carlo simulation of InGaAs/strained-InAs/InGaAs channel HEMTs considering self-consistent analysis of 2-dimensional electron gas

We calculated the unstrained and the strained band structures of InAs and carried out Monte Carlo simulation of InGaAs/strained-InAs/InGaAs composite channel high electron mobility transistors (HEMTs) considering 2-dimensional electron gas (2DEG) self-consistent analysis by solving Schrödinger and Poisson equations. With considering the effect of 2DEG, the drain-source current Ids decreases. However, the negative threshold voltage shift due to the short-channel effects is not affected by considering 2DEG. The threshold voltage shift occurs in the region L
_g
/d <; ~5 (L
_g
: gate length, d: sum of the barrier and channel layer thicknesses). At L
_g
= 20 nm, the simulated cutoff frequency f
_T
values were 943 GHz without 2DEG and 813 GHz with 2DEG. The trend of the f
_T
values with L
_g
reflects that of the electron velocities mainly.