Monte Carlo study of effective mobility in short channel FDSOI MOSFETs

Quasi-ballistic electron transport in ultrashort FDSOI devices is analyzed using Multi-Subband Monte Carlo (MSMC) simulations, taking into account the main scattering mechanisms: phonons, surface roughness, and charged impurities in the access regions. In particular, the ballistic resistance (defined as the resistance of the channel in absence of scattering) was extracted from ballistic simulations, and shown to be in good agreement with an accurate analytical model including the contact resistance effect. The simulations show an apparent mobility degradation when the channel length decreases, comparable to that observed in experiments, without requiring any additional scattering mechanism in order to explain it.