Kinetics of the C49-C54 transformation by micro-Raman imaging

The kinetics of the C49-C54 phase transition was analysed in TiSi2 thin fil ms obtained by reacting a Ti layer deposited on amorphous silicon. The C54 fraction was determined in the temperature range 680-720 degreesC by electr ical measurements and by micro-Raman spectroscopy. The Raman spectra were a cquired by scanning large silicide areas (100 X 50 mum) and images showing the evolution of the C54 grains at different times and temperatures were ob tained. The transformed fraction, the density and size distribution of the C54 grains were measured, and a detailed discussion of the errors associate d with the micro-Raman technique is presented. The data indicate that the n ucleation rate is not constant and the Johnson-Mehl-Avrami model cannot des cribe this transition. (C) 2001 Elsevier Science B.V. All rights reserved.