LAUSR

Valence Change Model describes the resistive switching in metal oxides-based devices as due to electro-reduction of the oxide and subsequent electro-migration of oxygen vacancies. Here we present cross-sectional X-Ray Energy Dispersive Spectroscopy elemental maps of Ta, O, N, and Ti in electro-formed TiN/TaO2.0/TiN structures. O, N, and Ti were exchanged between anode and functional oxide in devices formed at high power (~1 mW) but the exchange was below the detection limit at low power (<0.5 mW). All structures exhibit similar Ta-enriched and O-depleted filament formed by the elemental segregation in the functional oxide by the temperature gradient. The elemental interchange is interpreted as due to Fick's diffusion caused by high temperatures in the gap of the filament and is not an essential part of electro-formation.