Laser-induced phase transitions of Ge2Sb2Te5 thin films used in optical and electronic data storage and in thermal lithography

Abstract

Amorphous thin films of Ge2Sb2Te5, sputter-deposited on a ZnS-SiO2 dielectric layer, are investigated for the purpose of understanding the structural phase-transitions that occur under the influence of tightly-focused laser beams. Selective chemical etching of recorded marks in conjunction with optical, atomic force, and electron microscopy as well as local electron diffraction analysis are used to discern the complex structural features created under a broad range of laser powers and pulse durations. Clarifying the nature of phase transitions associated with laser-recorded marks in chalcogenide Ge2Sb2Te5 thin films provides useful information for reversible optical and electronic data storage, as well as for phase-change (thermal) lithography.