Formation and characterization of tungsten silicide layers

Tungsten silicide films formed via furnace annealing were studied. The tungsten layers were deposited either by evaporation or by r.f. sputtering onto Si(100) substrates as well as onto silicon layers deposited in situ. Tungsten deposited at room temperature yields poor silicides owing to the lack of permeability at the interface with silicon. This as well as the formation of voids in the substrate are discussed. Deposition onto substrates heated to 500 °C, however, always allows the formation of a silicide during subsequent annealing.