THE PHASE TRANSITION OF Bi-Pt ALLOYS AT THE INTERFACE OF Pt/SrBi_2Ta_2O_9 AND ITS EFFECT ON INTERFACE ROUGHNESS

摘要

Pt/SrBi_2Ta_2O_9(SBT)/CeO_2/Si (MFIS) structures were investigated for observing the change of electrical properties and morphology of interface of Pt/SBT after post-annealing of Pt top electrodes. The morphology of Pt/SBT interface became smooth and Bi oxide was formed at the bottom of Pt top electrode after post-annealing Pt top electrode. In order to describe the origin of these changes, Bi-oxide/Pt/SiO_2/Si structure was investigated with annealing temperatures about the reaction between Bi oxide and Pt. We can describe that the smooth interface of Pt/SBT and the consumption of metallic Bi, which the reason why electrical properties were drastically improved, is induced by the melting of Pt-Bi alloys and formation of Bi-oxide after post-annealing Pt top electrode.