Effect of oxygen partial pressure on crystal quality and electrical properties of RF sputtered PZT thin films under the fixed Ar flow and sputtering pressure

Abstract

Pb(Zr0·52Ti0.48)O3 films have been deposited on Pt/Ti/SiO2/Si (100) substrates by radio frequency (RF) magnetron sputtering method based on a sol-gel derived Pb(Zr0.30,Ti0.70)O3 (PZT) seed layer. Oxygen partial pressure-dependent crystal texture and electrical performance of PZT thin films, under the fixed Ar flow and sputtering pressure during deposition, were investigated. X-ray diffraction (XRD) analysis indicates that the major phase was transformed from perovskite phase containing little pyrochlore phase to pure perovskite phase with increasing oxygen partial pressure during sputtering. Atomic force microscopy (AFM) shows that the film processed by an O2/Ar composition of 10/90 demonstrated a compact and smooth surface. Dense perovskite structure without defects at the interface between seed layer and PZT film was observed utilizing Scanning electron microscope (SEM). Enhanced dielectricity (ε = 920.3, tan δ = 0.02 at 1 kHz) and ferroelectricity (2Pr = 22.8 μCcm−2, 2Ec = 97.9 kV/cm) were generated in the film processed with an O2/Ar composition of 10/90. Moreover, current-voltage (J-V) characteristic was also improved significantly with an O2/Ar composition of 10/90.