An investigation of the microstructural evolution of reactively sputtered TiNx to the TiN/TiSi2 bilayer, on (100)Si substrate, has been carried out with emphasis on the crystalline nature of the TiSi2. The nitrogen atoms in the TiNx film limit the available Ti atoms involved in the reaction with silicon and enhance the nitridation of the film. Hence, the thicknesses of both an amorphous interlayer or titanium silicide are much thinner than those from pure Ti film after rapid thermal annealing at various temperatures. Upon thermal annealing at above 600 degrees C, the TiNx film was divided into the bilayered structure of TiN/C49-TiSi2, in which the thickness of TiSi2 was far thinner and extremely uniform, and the overlying TiN was relatively thick and uniform compared with the case of pure Ti. Moreover, the TiSi2 was epitaxially grown on (100)Si substrate with the structural relationship of [001]TiSi2 parallel to[011]Si, (060)TiSi2 parallel to((2) over bar 00)Si, and (200)TiSi2 parallel to(02 (2) over bar)Si. Also, the stable character of the epitaxial C49-TiSi2 suppressed its transformation to C54 even after thermal annealing at 800 degrees C. Since the thickness of the TiSi2 from the TiNx was relatively thin and extremely uniform, the electrical propel-ties of the TiNx contacted shallow junctions were superior to those of the TiN/pure-Ti contacted junctions.