The microelectronics industry is extremely competitive in the increase of performances for devices or circuits. Nanowire architectures are now considered for the integration of strongly scaled devices as predicted for advanced technology nodes. The particular shape of nanowires combined to the reduction of geometrical dimensions (diameter of several atomic layers) leads to the emergence of physical phenomena on the MOSFET electrostatics characteristics such as quantum confinement (2D effects), short channel or band structure effects as well as the electronic transport with quasi-ballistic effect. In this work, we propose an analytical model including these last mechanisms for silicon GAA nanowires. In order to guarantee the pertinence of the model, numerical code have been developed such as a Schrödinger-Poisson solver for the band structure and a mobility calculation based on the Kubo-Greenwood formula including phonons, surface roughness and remote Coulomb scattering. The different results have been gathered in a continuous model, validated on numerical simulations and experimental data. Finally, a complete chain has been built to study the impact of last phenomena from the atomistic study, the MOSFET device characteristics up to small circuit performances.
