A TIME-DEPENDENT HYDRODYNAMIC DEVICE SIMULATOR SNU-2D WITH NEW DISCRETIZATION SCHEME AND ALGORITHM

A two-dimensional device simulator SNU-2D based on the hydrodynamic mo del is developed for the simulation and analysis of submicron devices. The simulator has the capacity for both self-consistent steady-state and transient-state simulation. To obtain better convergence and numer ical stability, we adopt an improved discretization scheme for the car rier energy flux equation and a new strategy for the transient simulat ion. In steady-state simulation the new discretization scheme shows a considerable improvement in convergence rate and numerical accuracy co mpared with the existing schemes. A transient simulation study is carr ied out on a deep submicron n-MOSFET used in the sense amplifier of SR AM cells to investigate the gate-switching characteristic. It is found that the behavior of carrier temperature is quasi-static during the s witching time even for very fast switching speed, while the behavior o f impact ionization under transient mode deviates from that under dc m ode as the switching speed increases.