Study of temperature dependent zirconium silicide phases in Zr/Si structure by differential scanning calorimetry

Abstract

The differential scanning calorimetry (DSC) technique is employed to study the formation of different silicide compounds of Zr thin-film deposited on a 100 μm-thick Si (1 0 0) substrate by dc sputtering. A detailed analysis shows that silicide layers start growing at ∼246 °C that changes to stable ZrSi2 at 627 °C via some compounds with different stoichiometric ratios of Zr and Si. It is further observed that oxygen starts reacting with Zr at ∼540 °C but a stoichiometric ZrO2 film is formed after complete consumption of Zr metal at 857 °C. A further rise in temperature changes a part of ZrSi2 to Zr-Silicate. The synchrotron radiation-based grazing incidence x-ray diffraction and x-ray photoelectron spectroscopy studies also corroborate the above findings. Atomic force microscopy is also carried out on the samples. It is evident from the observations that an intermixing and nucleation of Zr and Si occur at lower temperature prior to the formation of the interfacial silicate layer. Zr-Silicate formation takes place only at a higher temperature.