Thermal Stability of Nickel Silicide with Stressed Inter-Layer Dielectric Layer on Doped Si Substrate

In this study, the dependence of the thermal stability of Ni silicide on ILD layer is characterized. Boron and arsenic doped Si substrate were used to represent source/drain of MOSFETs. It is noteworthy that the thermal stability of Ni silicide exhibits different dependence on the stress of ILD layer. In the case of B-doped substrate, stressed Ni silicide always shows degraded characteristics than reference. However, tensile stressed case shows the most stable characteristics among all the samples in the case of the As-doped substrate. Therefore, stress of ILD layer should be decided carefully not to degrade the Ni-silicide property because agglomeration of the silicide can induce a lot of increase of junction leakage current.