Characteristics of Strontium Bismuth Tantalate Film with ZrO₂ Buffer Layer for Non-Volatile Memory Applications

Abstract

We have investigated the interfacial and electrical properties of metal-ferroelectric-insulator-semiconductor capacitors with SrBi₂Ta₂O₉ ferroelectric films grown on ZrO₂ buffer layer coated Si. Interfacial and surface roughness parameters of heterostructures were extracted from the simulation of specular x-ray reflectivity data. For as-deposited film, no interfacial layer is found between SBT and ZrO₂ from simulation data, however, an accurate fit can only be possible if a thin SiO₂ layer is assumed at ZrO₂/Si interface. On annealing, the formation of an inhomogeneous interfacial layer between SBT/ZrO₂ interfaces having thickness 1.3 nm is observed.

Keywords:

• Memory window
• x-ray reflectivity and ferroelectric properties