Influence of discrete impurity position in the channel of an ultra-small MOSFET

This paper discusses the influence of the channel impurity distribution on the transport and the drive current in a short-gate MOSFET. For this purpose, a careful description of electron–ion interaction suitable for the case of discrete impurities has been implemented in a 3D (three-dimensional) particle Monte Carlo simulator. This transport model is applied to the investigation of a 50 nm MOSFET operation. The paper shows that a small change in the position of a single discrete impurity may significantly influence the drain current. This effect is not only related to threshold voltage fluctuations but rather to variations in transport properties in the inversion layer.