Smallest (∼10 nm) phase-change marks in amorphous and crystalline Ge2Sb2Te5 films

Electrical nano-scale crystallization and amorphization in amorphous and crystalline Ge₂Sb₂Te₅ films have been studied using scanning probe microscopes. In scanning tunneling microscopes, the phase changes can be induced, not by tunneling currents, but by conducting currents flowing through contacted probes. In an atomic force microscope, metallic cantilevers can produce phase-change marks with minimal sizes of ∼10 nm. The crystallization and amorphization processes show different dependences upon thickness of Ge₂Sb₂Te₅ films. These features are discussed from thermo-dynamical and microscopic structural points-of-view.