Zirconium Titanate Thin Film Prepared by Surface Sol-Gel Process and Effects of Thickness on Dielectric Property

摘要

Single phase of multicomponent oxide ZrTiO₄ film could be prepared through surface sol-gel route simply by coating the mixture of 100 mM zirconium butoxide and titanium butoxide on Pt/Ti/SiO₂/Si(100) substrate, following pyrolysis at 450∩, and annealing it at 770 ∩. The dielectric constant of the film was reduced as the film thickness decreased due to of the interfacial effects caused by layer/electrode and a few voids inside the multilayer. However, the dielectric property was independent of applied dc bias sweeps voltage (-2 to +2 V).The dielectric constant of bulk film, 31.9, estimated using series-connected capacitor model was independent of film thickness and frequency in the measurement range, but theoretical interfacial thickness, t_i, was dependent on the frequency. It reached a saturated t_i value, 6.9∈, at high frequency by extraction of some capacitance component formed at low frequency range. The dielectric constant of bulk ZrTiO₄ pellet-shaped material was 33.7 and very stable with frequency promising as good applicable devices.