An application of Monte Carlo particle and relaxation time approximation modeling to quarter-micron Si MOSFETs is presented. Through a comparison between these two nonstatic models and a conventional model, nonstationary carrier transport is shown to dominate in 0.4 mu m or less channel devices, with peak velocities exceeding 1.0*10/sup 7/ cm/s. It is shown that the relaxation time approximation model tends to overestimate nonstationary carrier dynamics, especially the energy distribution.>

The current status of semiconductor device simulation at NTT is described. Device simulators at NTT are classified into two categories. One is the conventional macroscopic approach and the other is microscopic particle analysis using a Monte Carlo method. In this paper, these simulators are introduced together with the more interesting results. Through these examples, it is demonstrated that the device simulation takes an important role for accurate modeling of semiconductor devices. This report also concludes that the choosing the best simulation program for a given problem is the key to obtain effectively an accurate solution.