Study of structural and electrical properties of ferroelectric HZO films obtained by single-target sputtering
Mohammed-Bilal Hachemi, B. Salem, Vincent Consonni, Hervé Roussel, Alexandra Garraud, Gauthier Lefèvre, S. Labau, Skandar Basrour, A. Bsiesy
Abstract
In this work, we study the structural and electrical properties of Hafnium Zirconium Oxide (HZO) thin films deposited by Hf0.5Zr0.5O2 single-target sputtering to fabricate a TiN/(14-/22 nm-thick) HZO/TiN stack. The structural analysis of the HZO thin films performed by in situ x-ray diffraction upon thermal annealing shows the formation of the HZO orthorhombic phase at annealing temperatures as low as 370 °C. X-ray photoelectron spectroscopy interestingly reveals an identical chemical composition of the deposited HZO thin films and the sputtered target, i.e., an Hf:Zr ratio of 1:1. The current–voltage characteristic of the TiN/HZO/TiN stack shows a current density of 10−5 A/cm2 at an applied electric field of 1 MV/cm, which, being rather low, gives a strong indication of the good electrical quality of the HZO layer. Finally, a butterfly-like capacitance–voltage loop is obtained on the TiN/HZO/TiN stack, indicating a ferroelectric behavior of the HZO layer.