Modeling of main leakage currents and their contribution to channel current in Fin-FETs

Gate current present in double-gate fully depleted MOSFETs can significantly contribute to its measured channel current. For this reason the presence of direct tunneling and GIDL effects on the total gate and drain currents of Fin-FETs with different dimensions is analyzed. To fulfill this task, expressions for the leakage current due to direct tunneling and GIDL effects at the metal-gate/high-k structure were established and incorporated in the Symmetric Doped Double-Gate Model (SDDGM) for MOSFETs. It is shown that both phenomena have to be taken into account for precise modeling in all the operation regions. The behavior of gate tunneling current in all regimes of operation, as a function of applied potentials and transistor physical parameters, was derived and expressed in the form on a single equation, incorporated to the SDDGM. Agreement observed between modeled and experimental transfer characteristics in inversion, depletion and accumulation region was excellent for Fin-FETs with different dimensions.