Suppression of Lateral Encroachment of Ni Silicide into Si Nanowires Using Nitrogen Incorporation

Si nanowire (NW) FET is one of the promising candidates for high-speed LSI devices in the future. In order to reduce the parasitic resistances of Si nanowires, the silicidation of the S/D regions is a very effective method. However, it has been reported that the full-silicidation leads to excessive Ni diffusion into Si NWs and this phenomenon may lead to some adverse issues such as uncontrollable channel length as well as short circuit between source and drain. On the other hand, there is a report that the diffusion of Ni could be suppressed by nitrogen incorporation into the Ni film prior to the silicidation.We applied this method for Ni full-silicidation of Si NWs and investigated the effectiveness on this structure. We also investigated the mechanism for the suppression.