Synthesis and properties of phase-change Ge-Sb nanoparticles

We report on the synthesis and characterization of Ge ₁₅Sb ₈₅ phase-change nanoparticles by magnetron plasma sputtering and inert-gas condensation inside an ultra-high vacuum compatible system. Electrical and optical properties of Sb-rich nanoparticles for phase-change memory applications have been examined. The results show that phase-change properties of Ge ₁₅Sb ₈₅ material still exist for nanoparticles of 8.0 nm size. The amorphous to crystalline transformation proceeds at moderately elevated temperature (∼473 K) which shows that Ge ₁₅Sb ₈₅ nanoparticles are a good candidate for phase-change memory applications in terms of long data retention time. The observed phase transition in Ge ₁₅Sb ₈₅ nanoparticles is promising for down scaling the size of phase change solid-state memory devices.