Thermal nitridation of thin amorphous Ti-silicide films is studied. The use of hydrazine gas enables the nitridation at 500 °C, well below the nucleation temperature of Ti silicide. Transmission electron microscopy reveals that these TiSiN fims have amorphous structures, which are shown to be stable up to 750 °C. X-ray photoelectron spectroscopy indicates the simultaneous formation of Ti–N and Si–N bonds. This is consistent with the Ti–Si–N ternary phase diagram. Further, the presence of this nitrided film between Al and Si retards the interfacial reaction up to an annealing temperature of 550 °C near the eutectic point (577 °C) of an Al–Si system. ©1997 American Institute of Physics.