Improved Ohmic Contact Model for Accurate Simulation of GaN-based HEMTs Using Ensemble Monte Carlo Methods

Ensemble Monte Carlo simulation was performed to simulate the current gain cutoff frequency (f
T
) of an AlN/GaN HEMT. It was found that the donor density in the source ohmic neutral region should be larger than 5×10
²⁰
cm
^-3
to precisely calculate the drain current. The calculation results indicated that as high as 1.6 THz of f
T
was achieved with a gate length of 10 nm.