Using a two-dimensional ensemble Monte Carlo (EMC) method, the steady and transient properties of side-gated nanotransistors with single gate and double gate are studied in detail. Simulation results show that the double-gated nanotransistor has more powerful controlling ability on the channel than the single-gated one. The transient processes of the drain current for the two devices are both about 3 ps, which imply that the working speed of the two devices may reach about 0.3 THz. The detail of transient processes for the double-gated nanotransistor is trivial. But for the single-gated nanotransistor, the drain current response shows obviously oscillating during approaching the next steady state. The phenomenon of drain current oscillations is also discussed.

Using a two-dimensional ensemble Monte Carlo (EMC) method, the noise spectrum of a InGaAs-based nanoFET is studied in detail. Simulation results show that the noise spectrum consists of two maxima at frequencies of about 0.7 THz and 2 THz. The lower-frequency maximum is sensitive to the source-drain voltage, while that of the higher frequency one is not. These achievements are coincident with experimental results. Moreover, based on Dyakonv-Shur’s theory, the emergence of noise maxima is explained as the excitation of 2D plasma waves in the device.