Limitations of Hydrodynamic and Energy-Transport Models

Accurate description of nonlocal hot-carrier phenomena in modern semiconductor devices is becoming very important considering the rapid reduction of the feature size. Frequently used carrier transport models are the traditional drift-diffusion model and extended models which also consider the average carrier energy as an independent solution variable. While the drift-diffusion model is not capable of handling nonlocal effects, the latter model group provides a more accurate description. Several variants of hydrodynamic and energy-transport models have been published so far. Recent results show, however, that the average energy is in many cases not sufficient for accurate modeling. Both the transport models themselves and the models for the physical parameters seem to be affected.