Redistribution of boron during the formation of the cobalt suicides Co2Si, CoSi and CoSi2 has been studied. The suicides were formed by solid state reactions of cobalt deposited on boron implanted silicon. The suicide formation was determined by Rutherford backseat tering spectrometry (RBS), and the resulting redistribution of boron was studied using secondary ion mass spectrometry (SIMS). The study shows that the atoms participating in the suicide formation diffuse in the growing suicide without any mutual interference. Boron atoms in the consumed silicon layer redistribute within the formed suicide layer and accumulate at the surface, while boron in the underlying unconsumed silicon is unaltered, and no accumulation due to snowplowing occurs at the silicide/silicon interface.