Effect of N2O ratio on the crystallization temperature of ZrO2 film deposited on Si by reactive sputtering in Ar/O2/N2O plasma

The effect of nitrous oxide ratios in the Ar/O-2/N2O plasma on the ZrO2 films deposited on Si using dc magnetron reactive system is studied by differential scanning calorimetry (DSC) where the Ar: O-2 ratio is fixed at 4: 1. Further, grazing angle x-ray reflectivity (GIXRR), grazing angle x-ray diffraction (GIXRD) and atomic force microscopy (AFM) techniques are also employed to characterize the films. The DSC study shows an anomalous variation of the glass temperature when the N(2)Oratio in the Ar/O-2/N2O plasma changes from 0.25 to 2 with respect to the control ZrO2 sample deposited without N2O. An increase in glass temperature by similar to 70 degrees C is observed for the N-2 Oratio at 1. Afurther rise in N2O ratio results in the reduction of the glass temperature. The GIXRR study indicates that the thickness of the samples decreases with the increase in N2O ratios beyond 0.8. Further, increasing N2O ratio results in an increase in surface and interface roughness for the as-deposited samples. But both the roughnesses decrease upon annealing the samples above their respective crystallization temperatures. The AFM results also corroborates the observation. Moreover, the GIXRD study indicates the formation of G-Zr2ON2 along with the monoclinic and tetragonal ZrO2 at the highest ratio of N(2)Oin the Ar: O-2: N2O plasma.