Effects of S/D Doping Concentrations on Vertical Strained-SiGe Impact Ionization MOSFET Incorporating Dielectric Pocket (VESIMOS-DP)

The Vertical Strained Silicon Germanium (SiGe) Impact Ionization MOSFET with Dielectric Pocket (VESIMOS-DP) has been successfully developed and analyzed in this paper. The effect of Source and Drain (S/D) doping concentration to the VESIMOS-DP on the performance of the device in terms of sub threshold swing, threshold voltage and drain current has been observed in this paper. There are significant drop (from S=30mv/dec to S=19mv/dec) in sub threshold slope while threshold voltage is increase as the S/D concentration increases is observed in this paper. It is notable that for S/D doping concentration above 1019 atoms/cm3, there are significant increase in S values which is not recommended as the switching speed getting higher distracting performance of the device. However, too low doping concentration is not essential as it didn´t show any significance improvement on the performance of the device. Thus, optimum S/D doping concentration is imperative to obtain superb device characteristic Due to the DP layer, a stable VTH =1.35V obtained due to the vicinity of DP layer near the drain end has reduce charge sharing between the source and drain. The slight different and consistency of VESIMOS-DP sub threshold value (S = 19 mV/dec) has given advantages for incorporating DP layer near the drain end.