Effects of YSZ buffer layer on the electrical properties in Pt/SrBi2TaNbO9/YSZ/Si structure

Abstract

The electrical properties of Pt/SBTN/YSZ/SiOx/Si structure are investigated by changing oxygen partial pressure during deposition of the YSZ buffer layer. The YSZ layer:deposited without oxygen performs a role to reduce the SiOx layer thickness. However, the thin YSZ film deposited without oxygen show the poor leakage current properties due to the increase of the density of vacancy related defects compared to films deposited with oxygen. In order to prevent the degradation of electrical property, we perform two-step deposition method which sequentially changes the oxygen partial pressure during YSZ growing. The enhancement of ferroelectric properties of the SBTN as well as the suppression of the SiOx layer growth increase the memory window in this structure to 1.5 V at +/- 5 applied voltage.