Computation of drain and substrate currents in ultra-short-channel nMOSFETs using the hydrodynamic model

An attempt was made to develop a robust and efficient numerical solution of the hydrodynamic model which solves the energy balance equation and to compare predictions of this model, using one set of parameters, with experimental nMOSFET characteristics for a range of channel lengths down to ultrashort channels. The substrate current was calculated by direct integration of the energy distribution function to obtain the number of high-energy electrons. It is demonstrated that the hydrodynamic model can be used successfully to simulate silicon MOSFETs with channel lengths as short as 0.16 mu m. Equally important is the fact that one set of parameters is used to simulate devices with channel lengths varying from 0.90 mu m down to 0.16 mu m and all the parameter values used are physically justifiable. The importance of using a stable discretization method in the energy balance equation to avoid spurious numerical results is also shown.<>