Interdiffusion of multilayer ferroelectric thin films using YBa2Cu3O7-x as an intermediate layer

Abstract

Interdiffusion between layers in multilayer ferroelectric thin films was studied from their elemental depth profiles using secondary ion mass spectrometry. Among the films deposited on YBa2Cu3O7-x/CeO2/Si substrates, the interdiffusion is most pronounced for [Sr0.5Ba0.5]Nb2O6(SBN) films, less marked for Pb0.97La0.03(Zr1-xTix)(0.9925)O-3 (PLZT, x=0.54 or 0.34) films, and is least significant for BaTiO3 films. Higher substrate temperature used for growing SBN films is believed to be the main cause of interdiffusion. The larger proportion of cationic vacancies existing in PLZT films is another possible source inducing interdiffusion. Using YBa2Cu3O7-x/SrTiO3 as substrates substantially reduces the interdiffusion between layers. This is ascribed to the better crystallinity of the YBa2Cu3O7-x layers deposited on SrTiO3 substrates. These results indicate that both the characteristics of ferroelectric films and the underlying YBa2Cu3O7-x layers substantially modify the interdiffusion behavior between the layers. (C) 1996 American Institute of Physics.