Scanning electron microscope for in situ study of crystallization of Ge2Sb2Te5 in phase-change memory.
By introducing electrical connections into the chamber of a scanning electron microscope (SEM) via its holder assembly, it has become feasible to in situ observe and electrically characterize electronic devices. The in situ SEM was applied to investigate electric-pulse-induced behavior of Ge(2)Sb(2)Te(5) in a lateral phase-change memory cell. Randomly distributed nuclei with sizes from 20 to 80 nm were initiated at a low voltage pulse. Initially, grain growth depended strongly on pulse amplitude at around 60.3 nm/V and then a weak pulse amplitude dependence was observed at around 13.5 nm/V. Device resistance during crystallization dropped by two to three orders of magnitude with two falling steps, which probably resulted from amorphous to face-centered-cubic and subsequently to hexagonal transitions, respectively.
Yin
You
Y
Department of Production Science and Technology, Graduate School of Engineering, Gunma University, 1-5-1 Tenjin, Kiryu, Gunma 376-8515, Japan. yinyou@el.gunma-u.ac.jp
Niida
Daisuke
D
Ota
Kazuhiro
K
Sone
Hayato
H
Hosaka
Sumio
S