Investigations on the effect of substrate temperature on the properties of reactively sputtered zirconium carbide thin films

Reactively sputtered zirconium carbide thin films were grown on (100) silicon substrate and the influence of substrate temperature on the properties of the films were investigated. The substrate temperature was varied from ambient to 500 degrees C and partial pressures of the sputter gas and reactive gas (argon and methane) were optimised to obtain crystalline films. Structural characteristics showed that the films exhibit nanocomposite structure consisting of ZrC nanocrystallites embedded in amorphous carbon typically at lower growth temperature (T-S < 300 degrees C), and at higher growth temperatures film were highly textured. In addition, Films deposited at 325 degrees C showed a distinct increase in FWHM which had considerable effect on the mechanical properties of the film. Maximum hardness of 24.8 GPa was seen at 325 degrees C. Analysis of the chemical bonding with XPS suggested increase in percentage of sp(3) compared to sp(2) bonding at growth temperature of 325 degrees C. The changes in atomic bonding structures, their relative fractions with respect to substrate temperature were discussed. Transition from columnar crystallites to free of columnar features with subsequent increase in roughness of the film at 325 degrees C was studied using SEM and AFM respectively. (C) 2016 Elsevier B.V. All rights reserved.