Crystallization and resistivity of amorphous titanium silicide films deposited by coevaporation

Films of titanium silicide were deposited on oxidized silicon wafers by means of the coevaporation of titanium and silicon. The atomic concentration range 0?Si/Ti?4 was studied. The films were annealed in hydrogen ambient in the temperature range 300–1000 °C. For Si/Ti≊2, annealing between 800 and 900 °C results in the formation of TiSi2 with a resistivity as low as 15–25 μΩcm and a grain size of 200–500 Å. In situ annealing in a transmission electron microscope and differential thermal analysis show that the crystallization of the silicide starts at 350 °C. The properties of the as-deposited amorphous (Ti+Si) films were found to be consistent with theories for disordered metal-metal alloys. The resistivity behavior (a low temperature coefficient, which is independent of temperature and composition) can be described in terms of Mooij’s rule. The crystallization temperature of 350 °C is in agreement with a model proposed by Buschow.