Regensburg 2016 – scientific programme
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DS: Fachverband Dünne Schichten
DS 35: Thin Film Characterisation: Structure Analysis and Composition II
DS 35.11: Talk
Wednesday, March 9, 2016, 17:45–18:00, H8
Study of amorphous chalcogenide alloys by optical and electrical investigation — •Ju-Young Cho1 and Matthias Wuttig1,2 — 1I. Physikalisches Institut (IA), RWTH Aachen University, 52056 Aachen, Germany — 2JARA-FIT, RWTH Aachen University, Germany
Amorphous phase change materials (PCMs) show unusual phenomena compared to ordinary covalent glass. Amorphous PCMs usually show significantly different local chemical order as compared with their crystalline phase, while ordinary covalent glass exhibits a similar local chemical order as compared with its crystalline counterpart. Unraveling the local structure and the relevant characteristics is highly rewarding task because this is a key to understand the unique features of the amorphous PCMs, e.g. the extremely rapid crystallization, high fragility as well as temporal drift of the electrical resistance.
When alloying PCMs, constitute elements and compositional variation significantly affect the local chemical order of amorphous PCMs. This dependency becomes more obvious when PCMs and non-PCMs are alloyed. In this study, we have performed FT-IR and Raman spectroscopy, Van der Pauw and X-ray reflectivity measurements of co-sputtered amorphous chalcogenide alloy films with various compositions and elements to exploit the change in the structural properties as well as the crystallization kinetics of PCMs. The resulting insight will reveal the correlation between the local chemical order and the properties varying with composition, possibly enabling the prediction of phase change memory characteristics.