Dynamic Observation of Phase Transformation Behaviors in Indium (III) Selenide Nanowire-Based Phase Change Memory

Huang, Yu-Ting, Chun-Wei Huang, Jui-Yan Chen, Yi-Hsin Ting, Kuo-Chang Lu, Yu-Lun Chueh and Wen-Wei Wu, 2014

Image courtesy of ACS Nano

Abstract

Phase change random access memory (PCRAM) has been extensively investigated for its potential applications in next-generation nonvolatile memory. In this study, indium(III) selenide (In2Se3) was selected due to its high resistivity ratio and lower programming current. Au/In2Se3-nanowire/Au phase change memory devices were fabricated and measured systematically in an in situ transmission electron microscope to perform a RESET/SET process under pulsed and dc voltage swept mode, respectively. During the switching, we observed the dynamic evolution of the phase transformation process. The switching behavior resulted from crystalline/amorphous change and revealed that a long pulse width would induce the amorphous or polycrystalline state by different pulse amplitudes, supporting the improvement of the writing speed, retention, and endurance of PCRAM.

Impact Statement

The observation of dynamic changes in the phase transformation of indium (III) selenide (In2Se3) after Au/In2Se3-nanowire/Au phase change memory devices underwent a RESET/SET process in a TEM. The researchers used both pulsed and DC voltage swept modes. The switching showed that a long pulse width could force the transformation to amorphous or polycrystalline states depending on the pulse amplitudes. This discovery could aid the improvement of PCRAM writing speed, endurance and retention.