A study of diffusive transport in 14nm FDSOI MOSFET: NEGF versus QDD

Drain current in Ultra-Thin Body (UTBB) Fully-Depleted Silicon-On-Insulator (FDSOI) device is investigated using Non-Equilibrium Green Function (NEGF) simulations. The effects of phonons (PH) and surface roughness (SR) on saturation velocity are studied. We analyze the current and extract quantities relevant to Quantum Drift-Diffusion (QDD) solvers, such as the quasi-Fermi level, the quantum potential and the quasi-ballistic saturation velocity. In particular, the mobility in saturation regime is discussed and an approach based on the Scharfetter-Gummel scheme is presented, bridging the gap between NEGF and QDD frameworks.