Quantum simulation of an ultrathin body field-effect transistor with channel imperfections

Abstract

An efficient program for the all-quantum simulation of nanometer field-effect transistors is elaborated. The model is based on the Landauer–Buttiker approach. Our calculation of transmission coefficients employs a transfer-matrix technique involving the arbitrary precision (multiprecision) arithmetic to cope with evanescent modes. Modified in such way, the transfer-matrix technique turns out to be much faster in practical simulations than that of scattering-matrix. Results of the simulation demonstrate the impact of realistic channel imperfections (random charged centers and wall roughness) on transistor characteristics. The Landauer–Buttiker approach is developed to incorporate calculation of the noise at an arbitrary temperature. We also validate the ballistic Landauer–Buttiker approach for the usual situation when heavily doped contacts are indispensably included into the simulation region.