Dresden 2014 – scientific programme
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DS: Fachverband Dünne Schichten
DS 33: Focus session: Resistive Switching by Redox and Phase Change Phenomena IV (Kinetic in oxides and phase change)
DS 33.1: Talk
Wednesday, April 2, 2014, 16:45–17:00, CHE 89
Evidence for power-dependent SET kinetics in valence change memories — •Stephan Menzel1,2, Karsten Fleck2,3, Ulrich Böttger2,3, and Rainer Waser1,2,3 — 1Forschungszentrum Jülich GmbH, Jülich, Germany — 2Institut für Werkstoffe der Elektrotechnik II, RWTH Aachen University, Germany — 3JARA - Fundamentals of Future Information Technology, Jülich, Germany
Resistively switching thin oxide films based on the valence change mechanism (VCM) have attracted great attention for the potential use in future nonvolatile information storage. The oxide thin film resistance can be tuned by applying appropriate voltages, where the different resistance state encodes the digital information. The VCM cell stack typically consists of Metal-Insulator-Metal structure, whereas the I-layer is a thin oxide layer, e.g. TiOx, HfOx, TaOx or SrTiOx. The resistance change is initiated by migration of ions such as oxygen vacancies within the oxide layer and a subsequent valence change in the cation sublattice. It takes place locally along nanoscale filaments within the I-layer. VCM cells exhibit a highly nonlinear switching kinetics which origins in the temperature accelerated drift of oxygen vacancies. In this paper switching kinetics data of SrTiOx based devices at varying ambient temperature are presented that cover >10 orders of magnitude in switching time. The switching kinetics data is analyzed using a multidimensional electro-thermal simulation model. It is demonstrated that the switching kinetics are driven by the electric power rather than the applied voltage or electric field. The electric power is dissipated as Joule heat that accelerates the ion movement.