Direct observation of the lateral nonuniform channel doping profile in submicron MOSFET's from an anomalous charge pumping measurement results

Abstract

This paper reports a new model and characterization of the reverse short channel effect (RSCE) as result of the lateral nonuniform channel doping profile in submicron MOSFET's. The anomalous increase in the charge pumping current with decreasing channel length has been observed experimentally for the first time by using a charge pumping measurement. This is attributed to the enhanced nonuniform channel doping profile with the decreasing channel length as a result of the interstitial imperfections caused by OED or S/D implant. A simple and accurate model is proposed to determine the effective lateral nonuniform doping profile along the channel. The effective channel doping profile calculated from the new approach presents an obvious doping enhancement near the drain region of submicron devices by comparing with that of long channel devices. The simulated threshold voltages and I-V characteristics based on this profile show excellent agreement with the experimental data.