Effects of HfO2 buffer layer thickness on the properties of Pt/SrBi2Ta2O9/HfO2/Si structure

Abstract

We investigated structural and characteristic changes in thin HfO2 films (<10 nm) by varying their thicknesses and also examined their influence on the properties of Pt/SrBi2Ta2O9/HfO2/Si metal/ferroelectric/insulator/semiconductor (MFIS) structures. HfO2 films with different thicknesses were found to exhibit rather distinct characteristics and to profoundly affect the properties of the fabricated MFIS capacitor. We found that, when employing 3.2-nm-thick HfO2 as the buffer layer, the MFIS capacitor showed good memory performance at low operation voltage. However, this study demonstrated that some of the HfO2 limited its application in MFIS memory, even though it is the most promising alternative gate dielectric material.