Fabrication of phase-change Ge2Sb2Te5 nano-rings.

Phase-change material Ge2Sb2Te5 rings with nanometer-scale thickness have been fabricated using the photo-thermal effect of a focused laser beam followed by differential chemical etching. Laser irradiation conditions and etching process parameters are varied to control the geometric characteristics of the rings. We demonstrate the possibility of arranging the rings in specific geometric patterns, and also their release from the original substrate.