Differential Scanning Calorimetry Analysis of the Linear Parabolic Growth of Nanometric Ni Silicide Thin Films on a Si Substrate

The formation of nanometric Ni silicide films on a Si wafer is analyzed using differential scanning calorimetry (DSC) and isothermal x-ray diffraction measurements. The sensitivity of DSC is remarkable even in this experimental configuration constituted of a Ni/Si bilayer deposited on a Si substrate. Both methods confirm the sequential growth of Ni2Si and NiSi (for T<700 degreesC). However the kinetics of growth of the first silicide formed (Ni2Si) cannot be fitted, for the two sets of measurements, by a simple parabolic law. Better agreement is obtained using a linear-parabolic growth law and a smaller activation energy for the linear term (0.8 eV) than for the parabolic one (1.5 eV). (C) 2005 American Institute of Physics.