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DS: Fachverband Dünne Schichten

DS 20: Application of Thin Films

DS 20.2: Talk

Tuesday, March 15, 2011, 10:30–10:45, GER 38

The influence of the crystallinity of TiO₂ on the resistive switching behavior of memristor devices — •Hannes Mähne¹, Stefan Slesazeck¹, Stefan Jakschik¹, and Thomas Mikolajick^1,2 — ¹NaMLab gGmbH, Dresden, Germany — ²Institut für Halbleiter und Mikrosystemtechnik, TU Dresden, Germany

Since 1970, Chua postulates the existing of a memristor and HP found the first device in 2008, a lot of research has been done. Several research groups using successfully titanium oxide without detailed understanding of the switching mechanism. The following work fill a gap of information and create a link between the crystalline structure of TiO₂ and its switching parameters. In this work used structure consists of Si substrate with thermally grown SiO₂ and deposited Ti as adhesion layer before Pt was sputtered as an inert bottom electrode. After deposition of TiO₂, by RF sputtering from a TiO₂ target with additional 2 sccm O₂, the material is in an amorphous phase. To get different phases the samples are annealed in a RTP oven at 500^∘C and 700^∘C in Ar atmosphere and with O₂. The top electrode material was evaporated aluminum. To create a temperature stable bottom electrode, several bottom layer stacks are tested and results in a thick Pt layer on a preoxidized Ti adhesion layer. Otherwise the bottom electrode becomes damaged. A reason for this behavior is that thin Pt becomes crystalline and holes are created. Next to this, temperatures above 700^∘C causes cracks in the TiO₂ films. The change in crystallinity results in a change from a oxygen migration like switching in amorphous to a filament like switching behavior in the crystalline samples.