Characterization of the Dopant Dependence of Ni-Silicide on a SOI Substrate for a Nano-Scale CMOSFET

In this research, the dependency of Ni-Silicide properties, such as the sheet resistance and the cross-sectional profile, on the dopants for the source/drain and the gate has been characterized. Ni-silicide on a silicon on insulator (SOI) substrate exhibits quite different characteristics compared to that on bulk silicon. There was little difference in the sheet resistance between the dopants, such as B$_{11}$ and BF$_2$, just after formation of NiSi. However, the silicide properties showed a strong dependence on the dopants when thermal treatment was applied after silicidation. The B$_{11}$-implanted substrate showed quite thermal stable characteristics while the BF$_2$-implanted one showed degradation of thermal stability. Moreover, the As-doped substrate showed an abnormal formation of an oxide layer on the NiSi. The principal reason for the excellent property of B$_{11}$-doped sample is believed to be the retardation of Ni diffusion by the boron during high-temperature annealing. Therefore, retardation of Ni diffusion and suppression of abnormal oxidation are highly necessary for high-performance Ni-silicide technology for nano-scale complementary metal oxide semiconductor field effect transistors (CMOSFETs).