The matter transport of arsenic ions implanted into titanium silicide layers has been investigated after thermal diffusion treatment in the 800 °C–1100 °C temperature range. The arsenic atoms redistribute between TiSi2and Si with a segregation coefficient depending on temperature. The diffused amount increases linearly with the square root of annealing time at 1100 °C. Then‐doped shallow Si layer has a quite good electrical activity with a mean resistivity of about 1.2 M&OHgr; cm. The leakage current of the reverse‐biasedn+/pjunction is instead quite high. Stacking faults are observed in the diffused layer.