Effects of Compositional Segregation and Short Channel on Threshold Voltage of nMOSFET

摘要

This study calculates the threshold voltage (V_T) roll-off behavior caused by short channel effect (SCE) as a result of scaling and the reverse short-channel effect (RSCE) due to B segregation around source and drain junctions by using the 2D device simulator - SILVACO~(TM)-ATLAS. The simulation results are comparable with the experimental data. It suggests that the drift diffusion physics can predict SCE and RSCE very well to sub-0.25 mu Si n-MOSFET devices. The modeling results indicate the V_T roll off at shorter channel length for devices with higher substrate doping concentration. V_T increases if the local p-dopant segregation exists around the source and drain junction. It is observed that RSCE is more significant for devices with lower substrate doping concentration and shorter channel length.