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.