Effects of HfO_2 buffer layer thickness on the properties of Pt/SrBi_2Ta_1O_9/HfO_2/Si structure

摘要

We investigated structural and characteristic changes in thin HfO_2 films (<10 nm) by varying their thicknesses and also examined their influence on the properties of Pt/SrBi_2Ta_2O_9/HfO_2/Si metal/ferroelectric/insulator/semiconductor (MFIS) structures. HfO_2 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 HfO_2 as the buffer layer, the MFIS capacitor showed good memory performance at low operation voltage. However, this study demonstrated that some of the HfO_2 limited its application in MFIS memory, even though it is the most promising alternative gate dielectric material.