NEXAFS study of electronic and atomic structure of active layer in Al/indium tin oxide/TiO stack during resistive switching.

We have studied the stability of the resistive switching process in the Al/(InO)(SnO)/TiO assembly grown by atomic layer deposition. Besides electrical characterization the effect of electric field on the atomic electronic structure of the TiO layer was studied using near edge X-ray absorption fine structure (NEXAFS) spectroscopy. The region of the current instability in the I-V characteristics was revealed. Presumably this current instability is supported by the amorphous structure of the TiO film but is initiated by the surface morphology of the Al substrate. A formation of the O molecules was established which occurs specifically in the region of the current instability that is a result of electrical Joule heating manifestation.