Atomistic Simulation of Phonon-Assisted Tunneling in Bulk-like Esaki Diodes

To correctly describe band-to-band tunneling in semiconductor materials with an indirect band gap like silicon electron-phonon scattering must be taken into account. However, combining electron-phonon scattering and an atomistic full-band basis, as needed in nanoscale device simulations, is a real challenge from a computational and theoretical point of view. We have developed a quantum transport solver that can fulfill this requirement for realistic quantum well and nanowire structures. Transport in bulk-like tunneling diodes, the basic elements of tunneling FETs, for which several experimental data are available, could only be modeled ballistically so far. Hence, we present in this paper a first validation of electronphonon interaction in an atomistic full-band basis for bulklike structures by means of simulations of phonon-assisted band-to-band tunneling currents in Esaki diodes.