Time resolved CoSi2 reaction in presence of Ti and TiN cap layers

In this work we study the phase transition of Co/poly-Si layers capped with Ti or TiN films. Silicide reaction has been performed by isothermal annealing in the temperature range between 420 and 510 °C and studied by measuring the sheet resistance during time. The time interval associated to the CoSi–CoSi2 phase transition has been extracted as a function of the cap layer and the annealing temperature. The presence of the Ti cap systematically reduces the rate of CoSi2 formation with respect to the sample with TiN. It has been found that the cap type has an impact on the pre-exponential factor of the growth time but it does not affect the activation energy. As an effect, the silicide capped with Ti has a flat interface with the substrate.