RF noise and scaling in nanometer SOI MOSFETs: Influence of quasiballistic transport

摘要

An ensemble Monte Carlo investigation of electronic transport in ultra-scaled SOI MOSFETs (keeping constant field bias conditions and with gate lengths from 180 nm down to 20 nm) is presented, with particular attention to the influence of quasi-ballistic transport on the high-frequency noise. To this end, the movement of each individual particle crossing the device channel is registered and analyzed; thus allowing obtaining important transport quantities such as transit times, characteristic time between scatterings, etc. The results evidence that charge transport presents strongly quasi-ballistic features for gate lengths below 30 nm. It is found that, for a gate length equal to 20 nm, drain and gate noise become practically identical to the noise produced under a fully ballistic regime, which in fact represents a limit to the noise generated within the device channel in extremely short transistors.