ACTIVATION-ENERGY FOR THE C49-TO-C54 PHASE-TRANSITION OF POLYCRYSTALLINE TISI2 FILMS WITH ARSENIC IMPURITIES

The C49-to-C54 transition in TiSi2 was investigated using samples having submicron line width film, by an x-ray diffraction technique. Arrhenius plots of the transition rate show that the C49-to-C54 transition of polycrystalline TiSi2 films with arsenic impurities have an activation energy barrier strongly dependent on the arsenic concentration. The energy increases as a function of arsenic impurity concentration, from 3.5 eV for TiSi2 formed on Si substrate ion implanted with the dose of 2 X 10(15) cm-2, to 7.8 eV with the dose of 5 X 10(15) cm-2. The annealing time dependence of the x-ray intensity on (004) orientation indicates that TiSi2 formed on Si substrate with the arsenic dose of 2 X 10(15) cm-2 shows a diffusion-limited process and that with the dose of 5 X 10(15) cm-2 shows an interface-limited process. The arsenic precipitates act to pin the C49 phase in the C49-to-C54 transition.