Phase‐change memories

Abstract

Phase Change Materials are adopted in optical data storage and are currently evolving to become the active material of a new viable non‐volatile memory technology which is expected to eventually replace no‐longer‐scaling Flash memory technologies. Phase‐Change Memories store their information as the material phase of a chalcogenide metal alloy (high‐resistive amorphous, respectively low‐resistive crystalline phase), the most important compound being Ge2Sb2Te5 (GST). To give insight in this important evolution, the paper describes the different aspects of Phase‐Change Memories. It starts from basic operation principle and fundamental material properties (Sections 2 and 3). Vital to their operation are not only the vitrification and crystallization properties of the chalcogenide material, but also the phenomenon of electronic threshold switching enabling low‐voltage Joule heating in the amorphous phase. Understanding and modeling of these effects are described in Section 4. Cell concepts and integration technology aspects, including optimization schemes aimed at reducing the program current are covered in Section 5. Finally, the excellent reliability and scaling properties of Phase‐Change Memories are discussed in Sections 6 and 7. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)

First-principles calculation of lattice thermal conductivity in crystalline phase change materials: GeTe, Sb2Te3 , and Ge2Campi1, Paulatto2, Fugallo3 et al. 2017Phys. Rev. B10817850View full textAdd to dashboardCite

“…Chalcogenide alloys are attracting an increasing interest for their use in optical data storage [digital versatile disk (DVD)] and, more recently, in electronic nonvolatile memories [phase change memories (PCMs)] [1][2][3][4][5]. These applications rest on a fast and reversible transformation between the amorphous and crystalline phases upon heating.…”

Defect models and electrical storage mechanism in GeSbTe phase change materials

“…One of the leading contenders to replace Flash non-volatile memories is the Phase change Random Access Memory (PRAM) [1][2][3][4][5]. This uses phase change materials (PCMs) such as Ge 2 Sb 2 Te 5 , which are switched between their amorphous and crystalline states.…”

Nonlinear DC and Dispersive Conductivity of Ion Conducting Glasses and Glass Ceramics

“…For instance, phase change materials, such as chalcogenide glasses, are being used as non-volatile memory devices [7]. In these materials, local heating induced by an electric field transforms the highly resistive amorphous material into a low-resistive crystalline state.…”