Cobalt silicide thermal stability: From blanket thin film to submicrometer lines

The effect of lateral dimension scaling on the thermal stability of CoSi2 layers reacted on pre-amorphized chemical vapour deposited silicon has been demonstrated. Resistance measurements on both blanket and patterned silicide 100 nm thick have been performed in the temperature range between 850 and 1100 ¬?C. The annealing effect on the silicide linewidth and on the grain size distribution was studied by transmission electron microscopy plan-view. A strong correlation between line resistance and morphological change during the high temperature annealing has been found. The thermal degradation activation energies in blanket and patterned CoSi2 films have been compared and explained. Moreover. thermal stability dependence on line width on (001) silicon has been also proved and compared to previous results on polycrystalline substrate.