A PHYSICS-BASED SHORT-CHANNEL CURRENT-VOLTAGE MODEL FOR LIGHTLY-DOPED-DRAIN METAL-OXIDE-SEMICONDUCTOR FIELD-EFFECT-TRANSISTORS

In this paper we present a new analytical physics-based drain current model for fully overlapped and partially overlapped lightly-doped-drai n metal-oxide-semiconductor field-effect-transistors (LDD MOSFETs). Th e model was developed by starting from a two-dimensional Poisson equat ion, and including the effects of series resistances and velocity satu ration. In particular the phenomenon of surface accumulation and deple tion in the LDD region is included in the model to describe saturation I-V characteristics. The device is partitioned into the source, intri nsic channel, subdiffusion, and overlapped and non-overlapped lightly- doped drain regions. The device parameters such as local threshold vol tage and doping concentration are continuous along the channel. The mo del can describe the I-V characteristics and can be used to calculate the electric fields in the channel region and in the LDD region for th e device operated in both the linear and saturation regions. The accur acy of the presented model has been verified by the simulated data usi ng a fully numerical 2D simulator and the experimental data of LDD dev ices with various geometries.