Phase Transformations and Switching of Chalcogenide Phase-change Material Films Prepared by Pulsed Laser Deposition
September 14th, 2017 XINXING SUN Leibniz Institute of Surface Modification

Chalcogenide phase-change materials (PCMs) exhibit distinct rapid changes in optical and electrical properties upon repeatable switching between amorphous and crystalline structure, and are thus attractive for optical data storage and emerging non-volatile memory (PCRAM) applications. This talk will describe two projects from his Ph.D. work related to PCMs. In the first project, a non-volatile optical multilevel switching in GeTe phase-change films prepared by pulsed laser deposition was identified to be feasible and accurately controllable at a timescale of nanoseconds. Moreover, correlating the dynamics of the optical switching process and the structural information demonstrated not only exactly how fast phase change processes take place, but also, importantly, allowed the determination of the rapid kinetics of phase transformation on the microscopic scale. In the second project, the electrical memory switching behavior of Ge2Sb2Te5 phase-change thin films was investigated. Bipolar electrical switching of PCM memory cells at the nanoscale can be achieved and improvements of the performance in terms of RESET/SET operation voltage, On/Off resistance ratio and cycling endurance are demonstrated. The polarity-dependent resistance switching processes can be visualized simultaneously by topography and current images. The local microstructure on the nanoscale of such memory cells and the corresponding local chemical composition were correlated.

Seminar, September 14, 2017, 12:00. Seminar Room

Hosted by Simon Wall