4He+ ions backscattering spectrometry and x-ray diffractometry were used to study interactions between PtSi and Pt, NiSi and Ni, PdGe and Pd. Due to the dissociation of the compound the formation of a phase richer in metal was observed to grow at the original compound/metal interface in the temperature range considered, 280-325°C for Pt2Si, 325°C for Ni2Si and 180-260°C for Pd2Ge. The growth kinetics of these new phases (Pt2Si and Pd2Ge) follow a parabolic relation between thickness and annealing time. At a given temperature the growth rate of Pt2Si and Pd2Ge in compound-metal structure is a factor {Mathematical expression} higher than in the usual semiconductor-metal structure. © 1979 Springer-Verlag.