Quantum transport in a cylindrical sub-0.1 μm silicon-based MOSFET

A model is developed for a detailed investigation of the current flowing through a cylindrical sub-0.1 mum MOSFET with a closed gate electrode. The quantum mechanical features of the lateral charge transport are described by a Wigner distribution function which is explicitly dealing with electron scattering due to acoustic phonons and acceptor impurities. A numerical simulation is carried out to obtain a set of I-V characteristics for various channel lengths. It is demonstrated that inclusion of the collision term in the numerical simulation is important for low values of the source-drain voltage. The calculations have further shown that the scattering leads to an increase of the electron density in the channel thereby smoothing out the threshold kink in the I-V characteristics. An analysis of the electron phase-space distribution shows that scattering does not prevent electrons from flowing through the channel as a narrow stream, and that features of both ballistic and diffusive transport may be observed simultaneously. (C) 2002 Elsevier Science Ltd. All rights reserved.