Three-Dimensional Simulation of a Narrow-Width MOSFET

In this paper we illustrate the main features of a general-purpose three-dimensional device-analysis program, HFIELDS-3D, developed at the University of Bologna in the context of an EEC-supported ESPRIT Project. The program employs triangular-based prismatic elements, which provide a reasonable compromise between simplicity and flexibility, but it is not otherwise limited to any specific device structure. In the present implementation, the program handles Poisson and one-carrier continuity equation, which allows for the simulation of unipolar devices. As an example, a typical 3-D problem, the narrow-width effect, is investigated using a realistic device structure fully accounting for the typical bird´s beak. It is shown that not only the threshold voltage, but also the gain factor, and therefore the device transconductance, are affected by the narrow-width effect.