Fig. 2
From: Role of oxygen vacancies in ferroelectric or resistive switching hafnium oxide
a Time-of-flight secondary ion mass spectroscopy (ToF–SIMS) depth profile and high-angle annular bright-field (HAABF) TEM image of TiN/Hf0.5Zr0.5O2/TiN capacitor using H2O and O2 plasma (O2*) reactant. b Intensity fraction of Hf 4f oxide (blue), sub-oxide (red) peak depending on the deposition temperature. c Vo formation energy with various dopants. Dopants are classified by chemical group. d, e XPS spectra of 2-nm Hf0.5Zr0.5O2 on Mo and TiN electrodes, respectively. Stoichiometric (HfO2) and non-stoichiometric (HfO2–x) peaks are deconvoluted from the Hf 4f spectrum. a reproduced with permission from [39]. b data from [42]. c data from [57]. d, e data from [66]