Evaporated two‐layered thin films of Pd‐Ni, Pt‐Ni, and Pt‐Pd on single‐crystal Si have been vacuum annealed in the temperature range 200–900 °C. The sequence of films as well as substrate orientation have been varied. The silicide formation has been studied by MeV He+backscattering spectrometry and glancing angle x‐ray diffraction. The silicide layers are highly inhomogeneous in the elemental depth distribution for annealing below 600 °C. Above 700 °C, the distributions become homogeneous. The silicide‐substrate interface shows varying sharpness depending upon substrate orientation and evaporation sequence. We suggest the existence of ternary monosilicides of the type Pt1−xPdxSi, Pt1−xNixSi, and Pd1−xNixSi. The Pt1−xPdxSi ternary silicide is stable up to 900 °C; the others are not.