Growth Behavior and Electrical Properties of a (Na _0.5 K _0.5 )NbO ₃ Thin Film Deposited on a Pt/Ti/SiO ₂ /Si Substrate Using RFMagnetron Sputtering

Abstract

A crystalline (Na 0.5 K 0.5 )NbO 3 (NKN) phase was formed for a film grown at 600°C, but a K 5.75 Nb 10.85 O 30 (KN) second phase was also observed in this film. Formation of the KN phase was due to the evaporation of Na 2 O. A homogeneous NKN phase was developed in the film grown at 300°C and annealed at 800°C under a Na 2 O atmosphere. This film exhibited the following good electric and dielectric properties: a high dielectric constant of 237.4 with a dissipation factor of 0.93% at 100 kHz, a low leakage current density of 1.0 × 10 −8 A/cm 2 at 0.1 MV/cm 2 , and the high P r and d 33 values of 21.1 μC/cm 2 and 64.5 pm/V, respectively.