The effect of deposition power on the micro-structure and dielectric response of Pb0.4Sr0.6TiO3 thin films

We report the fabrication of Pb0.4Sr0.6TiO3 thin films with different microstructures and dielectric responses deposited on LaNiO3 buffered silicon substrate via the RF magnetron sputtering method with various deposition powers from 40 W to 120 W. Effects of the power on deposition rate, orientation, surface morphology and dielectric response were investigated. X-ray diffraction patterns indicated that the crystal orientation of thin films changes from (110) preferential orientation to random orientation with decreasing power, and finally to perfect (100) orientation. Moreover, the thin films prepared at lower power show more homogeneous grain size distribution and denser microstructure. The capacitance–voltage analysis revealed that the films deposited at lower powers show larger dielectric response and better tunability performance. Especially, large dielectric constant and tunability of 947 and 80.88% (@400 kV/cm), respectively, were obtained under a deposition power of 40 W.