Electrical characterization of shallow cobalt-silicided junctions

The impact of the thickness of the cobalt-silicide layer on the electrical diode characteristics will be reported, with particular emphasis on the current-voltage (I-V characteristics, the surface and bulk carrier recombination lifetime and the low-frequency noise. It is shown that for thicker silicides the generation-recombination of holes in the top n⁺-layer is enhanced, giving rise to a higher diffusion current, an increase in the noise and a larger surface recombination velocity. It is believed that these parameters are closely linked, as the underlying physical phenomenon is the minority carrier recombination. In addition, it is shown by transmission electron microscopy that the silicide-silicon interface roughness is increased for larger cobalt thickness, which may explain some of the observations.