Using hard X-ray photoelectron spectroscopy to study a SiO2/HfO2-based interface dipole modulation stack embedded in a metal–insulator-metal structure

Abstract Hard X-ray photoelectron spectroscopy was used to examine the interface dipole modulation of SiO 2 /1-monolayer titanium oxide/HfO 2 stack embedded in a metal–insulator–metal structure. Reversible shifts in the Si 1 s , Hf 3 d , and Ti 1 s photoelectron peaks were induced by electrical stress, and they indicate the switching of the potential profile inside the SiO 2 /titanium oxide/HfO 2 stack. Moreover, a proportion change in the Ti 3+ component correlates with the potential switching, and that correlation suggests that the structural change around the interface titanium atoms leads to the interface dipole modulation.