Formation and Characterization of NiSi-Silicided n+p Shallow Junctions

Abstract

NiSi-silicided n+p shallow junctions are fabricated by P+/F+ dual implantation into/through a thin NiSi silicide layer followed by low-temperature furnace annealing. The incorporation of fluorine atoms in the 61-nm-thick NiSi film retards film agglomeration, making the film stable up to 750 °C for 90 min. A forward ideality factor of 1.08 and a reverse bias current density (at 5 V) of 0.7 nA/cm2 can be attained for the NiSi (61 nm)/n+p junctions with an area of 580×580 µm2 fabricated by P+/F+ dual implantation at 35/30 keV to a dose of 5×1015/5×1015 cm-2 followed by 750 °C thermal annealing. The junction formed is about 71 nm from the NiSi/Si interface. Activation energy measurement shows that the reverse bias area current of the NiSi/n+p junctions is dominated by the diffusion current, while their reverse bias peripheral current is dominated by the minority generation current at room temperature. This implies the presence of generation centers in and/or close to the junction region along the perimeter.