O-doped Si2Sb2Te5 nano-composite phase change material for application of chalcogenide random access memory
Ting Zhang1, Zhitang Song, Bo Liu
1State Key Laboratory of Functional Materials for Informatics, Laboratory of Nanotechnology, Shanghai Institute of Micro-System and Information Technology, Chinese Academy of Sciences, Shanghai 200050, China.
Abstract:
A method to prepare nano-composite phase change material was proposed and demonstrated by oxygen doping into Si2Sb2Te5 material. According to transmission electron microscope images, Si-Sb-Te-rich domains are separated from each other by SiOx-rich domains within the material. A proper dose of O-doping into Si2Sb2Te5 significantly reduces the grain size of the phase change material. Average size of Si-Sb-Te-rich domains is about 10 nm. Such separation will limit the phase-change to a relatively small volume. The reduction of grain size further results in the promotion of data retention and thermal stability of the material. Memory device based on O-doped Si2Sb2Te5 nano-composite phase change material, with a bottom electrode contact of 260 nm in diameter, was fabricated and characterized. The memory cell shows a better electrical performance compared with the Ge2Sb2Te5 based one.
