Titanium disilicide (TiSi2) films formed from varying compositions of co-deposited Ti and Si on a Si substrate and annealed in argon at 850 degrees C have been characterized by Rutherford backscattering, Auger electron spectroscopy, transmission electron microscopy, atomic force microscopy, and high resolution X-ray diffraction. As-deposited films (TiSix) with x < 2 form a TiOxN1-x film on top of a TiSi2 film after annealing, while "Si-rich" (x > 2) film form TiSi2 with a poly Si film on top. This result is explained by the strong driving force of Ti to form an oxide or nitride with ambient gases while Si must diffuse through the growing film to form TiSi2. An "Si-rich" as-deposited composition (x > 2) results in less interface roughening between the TiSi2 film and Si substrate after annealing, as well as greater residual wafer curvature as compared to the other samples, The reduced wafer curvatures in the "Si-deficient" samples is attributed to the presence of the TiOxN1-x film which acts to counter the stress in the TiSi2 film.