Structural and electrical properties of (Ti_0.9Zr _0.1)Si₂ thin films on Si(111)

Alloy films of Ti and up to 20% Zr were prepared by codeposition onto Si(111) surfaces in ultrahigh vacuum. After in situ thermal annealing at temperatures of ∼600°C, the films form the C49 phase and are stable in this phase up to at least 910°C. In contrast, Ti films on Si(111) initially react to form the C49 phase and transform to the C54 phase at ∼700°C. The surfaces of the (Ti_0.9Zr_0.1)Si₂ alloy films are studied by atomic force microscopy and are shown to be smoother than the surfaces of TiSi₂ films on Si substrates. In addition the tendency to island formation is also not observed for annealing temperatures less than 910°C. The sheet resistivity of the (Ti_0.9Zr_0.1) Si₂ alloy films is found to be ∼46 μΩ cm for annealing temperatures from 600 to 910°C.