Characterization of the local mechanical stress induced during the Ti and Co/Ti salicidation in sub-0.25 μm technologies

Abstract

In this article, micro-Raman spectroscopy measurements of the local mechanical stress in the silicon substrate induced by the Ti and Co/Ti salicidation were combined with simulations by finite element modeling down to 0.1 μm technologies. It is shown that the scaling possibilities of TiSi2 and of CoSi2 will both be hampered by the stress induced during the salicidation and will result in the generation of 60° dislocations in the silicon substrate. These experiments prove that, because of the difference in material properties between TiSi2 and CoSi2, a higher stress is generated in the silicon substrate during the Ti salicidation than during the low stress Co/Ti-salicidation process. Therefore, the mechanical characteristics related to the silicide formation become a critical parameter in the optimization of the silicide process.