Dresden 2009 – wissenschaftliches Programm

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MM: Fachverband Metall- und Materialphysik

MM 33: Phase Transitions I

MM 33.2: Vortrag

Mittwoch, 25. März 2009, 15:00–15:15, IFW B

Crystallization kinetics in materials for PCRAM — •Andreas Kaldenbach, Martin Salinga, Carl Schlockermann, and Matthias Wuttig — I. Institute of Physics (IA), RWTH Aachen University, 52056 Aachen, Germany

Phase-Change RAM is one of the most promising candidates for next generation electrical memory devices. One of its key features is the non-volatility of the stored data, which is due to a permanent structural rearrangement in the used phase change materials: the switching between a highly resistive amorphous state and a low resistance crystalline one. Although already utilized in memory applications, the fundamental mechanism of crystallization kinetics in these materials is still not fully understood. A continuous investigation of the temperature dependence of crystal nucleation and growth is very challenging, since crystallization speed of phase change materials is extremely fast at temperatures between glass transition temperature and the melting point. Until now, this difficulty has been bypassed by extrapolating data taken near the glass transition temperature or close to the melting point, where crystallization is rather slow.

The described experimental gap will be closed by a currently developed setup combining optical and electrical measurements to investigate the crystallization kinetics on a nanosecond timescale. It uses a pulsed laser to thermally induce the switching and a probe laser to measure the changing reflectivity during the switching process. Experimental results from the new setup will be compared with existing theories.