Published online by Cambridge University Press: 22 February 2011
Gadolinium silicide with its attractive features of low formation temperature of about 350°C and low Schottky barrier height on n-type single-crystal silicon substrates (ϕnB1∼O.4ev,ϕpB ∼ 0.7ev) was chosen for studying the feasibility of forming shallow uniform contacts. Samples with various compositions prepared by both bilayer evaporation with a configuration of Si(α)/Gd/Si(xtl) and coevaporation with a Si−Gd /Si(xtl)structure were used for studying the contact formation as a function of composition and heat treatment. We found that shallow contact formation can be achieved provided that the following conditions are met: (a) for bilayer evaporation, the atomic ratio of Si(α)/Gd ≥ 2 should be maintained, (b) for coevaporation, the Si to Gd atomic ratio between 1.7 and 2.0 is desired. The bilayer deposition scheme appears to be a more convenient technique to use in practice.