Laser-induced phase transitions of Ge₂Sb₂Te ₅ thin films used in optical and electronic data storage and in thermal lithography

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.