Nanomeasurement and fractal analysis of PZT ferroelectric thin films by atomic force microscopy

In this study, the radio frequency (RF) magnetron sputtering process is used to generate a PZT ferroelectric thin film on a silicon substrate. The surface characteristics of this lead zirconate titanate film Pb(Zr_x Ti_1-x)O₃ is then investigated by means of an atomic force microscopy (AFM) method. The relationship between the temperature of the rapid thermal annealing (RTA) process and the characteristics of the resulting microstructure is also examined. Various aspects of the surface are investigated, including its roughness, its microstructure and its fractal characteristics. The results demonstrate that higher annealing temperatures reduce surface roughness and promote increased grain size due to the phase transformations which are induced within the microstructure. The fractal analysis reveals that the fractal dimension, D_s, increases for larger AFM scan images, and that the value of D_s falls within the range 2.10-2.50 depending upon the scanned length/area and is calculated by the structure function. Finally, it is determined that the phase transformations which occur at higher annealing temperatures result in higher fractal dimensions.