The previous decade witnessed the validity of semi-classical models, but questioned for more rigorous quantum transport formalisms that would become necessary to explain the behavior of charge carriers was expected with some concern. The nano-objects emerging from bottom-up nanotechnology as well as in ultra-scaled top-down nano-transistors, a new physics including quantum features has emerged and cannot be properly captured by the conventional models of device physics. For instance, in ultra-thin body (UTB) MOSFET, such as FD-SOI-FET, Fin-FET or Double-Gate (DG) MOSFET (which are considered the most promising device architectures likely to overcome shortchannel effects that dramatically affect conventional bulk-MOSFET), a silicon channel thickness smaller than 1 nm will have to be considered in the near future.
It yields a strong quantization of electron gas in a direction perpendicular to the gate stack, which results in significant changes in the space and energy distributions of particles and may be reflected in the device operation and characteristics. Furthermore, for gate length in the below sub-10 nm range, the wave-like nature of electrons may give rise to source-drain tunneling through the channel barrier and to quantum reflections in the channel.
The solution of Wigner transport equation under the influence of the potential, whose rapid space variations generate quantum effects the and its application to the study of quantum transport problems in some typical nanodevices. The technique is able to correctly treat typical situations of quantum ballistic transport (interaction of a Gaussian wave packet with a tunneling barrier), as well as semi-classical transport.
The most widely used non-equilibrium Green's function (NEGF) approach is incapable to model the carrier scattering mechanisms along with the contact modeling. Thus the Wigner function approach may be more efficient in intermediate regimes, namely in between quantum coherent and semi-classical situations, which require scattering effects to be included.
User has flexibility to switch themselves from Monte-Carlo (MC) to Wigner-Monte-Carlo (WMC) TNL-PD simulator depends upon requirements.