Experimental Evaluation of Effects of Channel Doping on Characteristics of FinFETs

We investigated channel doping in fin-type double-gate (DG) MOSFETs. We demonstrated through experiments that the threshold voltage was more sensitive to the dopants in the accumulation mode than in the inversion mode. We also found that significant deviation in the threshold voltage from the expected value arose in ultrathin fin-type DG MOSFETs. We attributed this phenomenon to the unexpected dopant loss from the ultrathin channels due to segregation. This finding means that careful doping adjustments must be made in ultrathin-channel devices.