RESEARCH OF THE EFFECT OF ANNEALING TEMPERATURE OF REFRACTORY METAL SILICIDE FILMS ON THE ATOMIC RATIO Si/METAL

With an increase in the degree of integration and a decrease in the size of VLSI elements, the problems of creating contacts and interconnects to ultrafine structures cannot be solved using only metal films – the requirements for ensuring the thermal stability of materials used as contacts and interconnects increase. Refractory metal silicides are promising materials for use in metallization systems. In order to evaluate the thermal stability of silicides, we studied the change in the Si/metal atomic ratio in films of silicides of refractory metals W, Mo, and Ta subjected to annealing in an inert gas and thermal oxidation. It is shown that, as a result of heat treatment, the thickness of silicon-enriched films decreases, while that of metal-enriched films increases. Heat treatment of TaSix, WSiy, and MoSiz films on silicon substrates leads to equilibrium values of the parameters: x = y = 2,2, z = 2,1, which remain irrespective of the nature of the annealing environment.

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