Current-voltage characteristics of a silicon nanowire transistor

The nanowires and nanotubes are being considered as the best candidates for high-speed applications. It is shown that the high mobility does not always lead to higher carrier velocity. The ultimate drift velocity due to the high-electric-field streaming are based on the asymmetrical distribution function that converts randomness in zero-field to streamlined one in a very high electric field. The limited drift velocity is found to be appropriate thermal velocity for a nondegenerately doped sample of silicon, increasing with the temperature, but independent of carrier concentration. However, the limited drift velocity is the Fermi velocity for a degenerately doped silicon nanowire, increasing with carrier concentration but independent of temperature. The results obtained are applied to the modeling of the current-voltage characteristics of a nanowire transistor.