Schottky barrier (SB)-MOSFETs with NiSi and epitaxial NiSi 2 S/D contacts with gate lengths as small as 20nm are presented. Epitaxial NiSi 2 FETs show higher on-currents than corresponding NiSi devices due to its lower SB height. A striking observation is that tunnelling currents through the fairly large SB decrease at very short gate lengths in SB-MOSFETs, in contrast to the scaling behavior of conventional MOSFETs. Simulations indicate that the potential in the channel increases due to overlap of the high source and drain barriers with decreasing gate length, leading to lower currents. Boron implantation into the silicide (IIS) was used to lower the SBH. Devices with epitaxial NiSi 2 show an improved performance after barrier lowering by (IIS). It is shown, that the parasitic potential increase of the two S/D Schottky barriers can be either minimized by IIS and by enhanced gate control due to EOT scaling using high-k as the gate oxide.