Hard x-ray photoelectron spectroscopy study of the electroforming in Ti/HfO2-based resistive switching structures

The chemical and electronic modifications induced by the electroforming process on the Ti/HfO2/TiN-based resistive switching devices were investigated by non-destructive hard x-ray photoelectron spectroscopy (HAXPES). The results indicate an increase of the titanium top electrode oxidation at the interface with HfO2 after the electroforming process. Additionally, the binding energy values of the HAXPES peaks of the electroformed sample increased as compared to the as-prepared sample. The observed changes between both samples are attributed to the creation of n-type defects, such as oxygen vacancies, in the HfO2 layer near the Ti interface during the electroforming process. (C) 2012 American Institute of Physics. [http://dx.doi.org/10.1063/1.4728118]