Effect of silicon substrate amorphization on the kinetics of reaction between a titanium thin film and silicon

Abstract

The activation energy of C49 TiSi2 formation by thermal annealing of a single thin Ti film on a Si substrate was obtained using differential scanning calorimetry. Si substrates with different degrees of amorphization were used. In all cases, an exothermic reaction corresponding to C49 TiSi2 formation was observed. Using a Kissinger analysis, the activation energy was calculated to be 1.41-2.02 eV. With increasing degree of substrate amorphization, the activation energy of C49 TiSi2 formation initially increases before it decreases. It was found from X-ray diffraction measurement that, on a crystalline Si substrate, Ti5Si3 formed prior to C49 TiSi2. With increasing substrate amorphization, both Ti5Si3 and Ti5Si4 were observed. We believe that the formation of different C49 TiSi2 precursor phases causes the change in activation energy.