Atomic migration in phase change materials
Authors:
- 1 December 2013
- conference paper
- Published by Institute of Electrical and Electronics Engineers (IEEE)
- No. 01631918,p. 22.3.1-22.3.4
Abstract
During normal operation of Phase Change Memory (PCM) cells active materials undergo very high electrical and thermal stresses that cause a motion of the different atoms leading to composition variation which has a fundamental impact on performance and reliability. In order to address this issue we introduce here a comprehensive 3D physical model for mass transport in chalcogenide materials. In addition to the driving force for atom diffusion coming from concentration gradient and electric field, the model also accounts for the effect of temperature gradient and phase segregation. This new diffusion model is coupled with a calibrated electro-thermal-phase change model, thus providing a unified framework for the self-consistent simulation of both the electro-thermal and the phase/material change problems. The model is applied to the study of different types of PCM cells showing good agreement with experiments and demonstrating in particular the fundamental role played by the temperature profile.Keywords
This publication has 9 references indexed in Scilit:
- Breakdown of Stokes–Einstein relation in the supercooled liquid state of phase change materialsPhysica Status Solidi (b), 2012
- Voltage polarity effects in Ge2Sb2Te5-based phase change memory devicesJournal of Applied Physics, 2011
- Atomic migration in molten and crystalline Ge2Sb2Te5 under high electric fieldApplied Physics Letters, 2009
- Threshold switching and phase transition numerical models for phase change memory simulationsJournal of Applied Physics, 2008
- Phase separation behavior of Ge2Sb2Te5 line structure during electrical stress biasingApplied Physics Letters, 2008
- Why molecules move along a temperature gradientProceedings of the National Academy of Sciences, 2006
- Crystallization Behavior and Physical Properties of Sb-Excess Ge[sub 2]Sb[sub 2+x]Te[sub 5] Thin Films for Phase Change Memory (PCM) DevicesJournal of the Electrochemical Society, 2006
- Phase-field model for the dopant redistribution during solid phase epitaxial regrowth of amorphized siliconMaterials Science and Engineering: B, 2004
- Phase diagram of the ternary system Ge-Sb-TeThermochimica Acta, 1986