Flexible Electronics Applications of Ge-Rich and Se-Substituted Phase-Change Materials in Nonvolatile Memories

Abstract

Flexible electronics which are easy to manufacture and integrate into everyday items require suitable memory technology that can function on flexible surfaces. Herein, the properties of Ge-rich GeSbTe (GST) and Se-substituted GeSbSeTe (GSST) phase-change alloys are investigated for application as nonvolatile write-once and rewritable memories in flexible electronics. These materials have a higher crystallization temperature than the archetypal composition of Ge2Sb2Te5 and hence better data retention properties. Moreover, their high crystallization temperature provides for a particularly straightforward implementation of a write-once memory configuration. Material properties of Ge-rich GST and GSST are measured as a function of temperature using four-point probe electrical testing, Raman spectroscopy, and X-ray diffraction. Following this, the switching of flexible memory devices is investigated through both simulation and experiment. More specifically, crossbar memory devices fabricated using Ge-rich GST are experimentally fabricated and tested, while the operation of GSST pore cell structures suitable for flexible memory applications is demonstrated through simulation.