A crystalline interfacial bilayer, consisting of about 5nm each of RhSi and Rh2Si was found after E-beam deposition of 95nm of Rh onto either Si[100] or α-Si substrates. Cross sectional TEM of the as-deposited and annealed specimens showed no change occurred after 24hrs at 200° C. With infinite supply of Si, as on the Si[100] substrate, RhSi was found as a major growing phase, although Rh2Si also grew at a much slower rate. With a limited supply of Si, as in the α-Si case, RhSi first formed until all α-Si was consumed (2 hrs at 400°C) and then transformed partially to Rh2Si after 4 hrs at 400°C. This transformation could be confirmed by RBS since Rh2Si layer thickness exceeded 30nm