Role of activation energy in resistance drift of amorphous phase change materials

The time evolution of the resistance of amorphous thin films of the phase change materials Ge2Sb2Te5, GeTe and AgIn-Sb2Te is measured during annealing at T=80°C. The annealing process is interrupted by several fast temperature dips to determine the changing temperature dependence of the resistance. This procedure enables us to identify to what extent the resistance increase over time can be traced back to an increase in activation energy EA or to a rise of the prefactor R*. We observe that, depending on the material, the dominating contribution to the increase in resistance during annealing can be either a change in activation energy (Ge2Sb2Te5) or a change in prefactor (AgIn-Sb2Te). In the case of GeTe, both contribute about equally. We conclude that any phenomenological model for the resistance drift in amorphous phase change materials that is based on the increase of one parameter alone (e.g. the activation energy) cannot claim general validity.

[1]  Syo Matsumura,et al.  Structural relaxation of amorphous silicon carbide. , 2002, Physical review letters.

[2]  Shih-Hung Chen,et al.  Phase-change random access memory: A scalable technology , 2008, IBM J. Res. Dev..

[3]  Byoungil Lee,et al.  Resistance and Threshold Switching Voltage Drift Behavior in Phase-Change Memory and Their Temperature Dependence at Microsecond Time Scales Studied Using a Micro-Thermal Stage , 2011, IEEE Transactions on Electron Devices.

[4]  Daniel Krebs,et al.  The influence of resistance drift on measurements of the activation energy of conduction for phase-change material in random access memory line cells , 2012 .

[5]  D. Ielmini,et al.  Recovery and Drift Dynamics of Resistance and Threshold Voltages in Phase-Change Memories , 2007, IEEE Transactions on Electron Devices.

[6]  G. F. Iriarte.  Growth of nickel silicide (NiSix) nanowires by silane decomposition , 2011 .

[7]  Y.J. Song,et al.  Two-bit cell operation in diode-switch phase change memory cells with 90nm technology , 2008, 2008 Symposium on VLSI Technology.

[8]  D. Ielmini,et al.  Modeling of Threshold-Voltage Drift in Phase-Change Memory (PCM) Devices , 2012, IEEE Transactions on Electron Devices.

[9]  Daniele Ielmini,et al.  Statistics of Resistance Drift Due to Structural Relaxation in Phase-Change Memory Arrays , 2010, IEEE Transactions on Electron Devices.

[10]  M. Wuttig,et al.  Stoichiometry dependence of resistance drift phenomena in amorphous GeSnTe phase-change alloys , 2013 .

[11]  Guido Torelli,et al.  A Bipolar-Selected Phase Change Memory Featuring Multi-Level Cell Storage , 2009, IEEE Journal of Solid-State Circuits.

[12]  A. Pirovano,et al.  A physics-based model of electrical conduction decrease with time in amorphous Ge2Sb2Te5 , 2009 .

[13]  Andrea L. Lacaita,et al.  Temperature acceleration of structural relaxation in amorphous Ge2Sb2Te5 , 2008 .

[14]  Yang Zhao,et al.  Steel stress monitoring sensor based on elasto-magnetic effect and using magneto-electric laminated composite , 2012 .

[15]  D. Jeong,et al.  Multi-level cell storage with a modulated current method for phase-change memory using Ge-doped SbTe , 2011 .

[16]  Kumar Virwani,et al.  Observation and modeling of polycrystalline grain formation in Ge2Sb2Te5 , 2012 .

[17]  Hideki Horii,et al.  A microscopic model for resistance drift in amorphous Ge2Sb2Te5 , 2011 .

[18]  P. Fantini,et al.  Band gap widening with time induced by structural relaxation in amorphous Ge2Sb2Te5 films , 2012 .

[19]  D. Ielmini,et al.  Reliability Impact of Chalcogenide-Structure Relaxation in Phase-Change Memory (PCM) Cells—Part II: Physics-Based Modeling , 2009, IEEE Transactions on Electron Devices.

[20]  Daniele Ielmini,et al.  Evidence for trap-limited transport in the subthreshold conduction regime of chalcogenide glasses , 2007 .

[21]  S. Poon,et al.  Generation of dangling bonds by high temperature annealing and hopping conduction in amorphous silicon films , 1980 .

[22]  P Jost,et al.  Disorder-induced localization in crystalline phase-change materials. , 2011, Nature materials.

[23]  A. Pirovano,et al.  Statistical and scaling behavior of structural relaxation effects in phase-change memory (PCM) devices , 2009, 2009 IEEE International Reliability Physics Symposium.

[24]  J. Robertson,et al.  Reduction in defect density by annealing in hydrogenated tetrahedral amorphous carbon , 1998 .

[25]  Kailash Gopalakrishnan,et al.  Overview of candidate device technologies for storage-class memory , 2008, IBM J. Res. Dev..

[26]  Yeonwoong Jung,et al.  Extremely low drift of resistance and threshold voltage in amorphous phase change nanowire devices , 2010 .

[27]  Temporal Changes of Parameters in Phase Change Memory , 2008, 2008 International Symposium on VLSI Technology, Systems and Applications (VLSI-TSA).

[28]  M. Kastner.  Compositional Trends in the Optical Properties of Amorphous Lone-Pair Semiconductors , 1973 .

[29]  M. Kund,et al.  Nanosecond switching in GeTe phase change memory cells , 2009 .

[30]  Martin Salinga,et al.  Role of activation energy in resistance drift of amorphous phase change materials , 2014, Front. Phys..

[31]  M. Breitwisch,et al.  Estimation of amorphous fraction in multilevel phase change memory cells , 2009, 2009 Proceedings of the European Solid State Device Research Conference.

[32]  H. Laborit,et al.  [Experimental study]. , 1958, Bulletin mensuel - Societe de medecine militaire francaise.

[33]  Field-accelerated structural relaxation in the amorphous state of phase change memory , 2013 .

[34]  K. Kelton,et al.  Kinetics of structural relaxation in several metallic glasses observed by changes in electrical resistivity , 1984 .

[35]  D. Ielmini,et al.  Modeling of Threshold Voltage Drift in Phase Change Memory (PCM) Devices , 2012, 2012 4th IEEE International Memory Workshop.

[36]  C. Lam,et al.  Resistance drift in phase change memory , 2012, 2012 IEEE International Reliability Physics Symposium (IRPS).

[37]  C. M. Garner,et al.  Amorphous Thin Films , 1973 .

[38]  M. Wuttig,et al.  Phase-change materials for rewriteable data storage. , 2007, Nature materials.

[39]  Matthias Wuttig,et al.  Impact of DoS changes on resistance drift and threshold switching in amorphous phase change materials , 2012 .

[40]  D. Ielmini,et al.  Temperature- and time-dependent conduction controlled by activation energy in PCM , 2010, 2010 International Electron Devices Meeting.

[41]  D. Adler,et al.  Valence-Alternation Model for Localized Gap States in Lone-Pair Semiconductors , 1976 .

[42]  Daniele Ielmini,et al.  Physical origin of the resistance drift exponent in amorphous phase change materials , 2011 .

[43]  Young‐Chang Joo,et al.  Study on the Resistance Drift in Amorphous Ge2Sb2Te5 According to Defect Annihilation and Stress Relaxation , 2012 .

[44]  D. Ielmini,et al.  Role of mechanical stress in the resistance drift of Ge2Sb2Te5 films and phase change memories , 2011 .

[45]  V. Karpov,et al.  Localized states in glasses , 1989 .

[46]  L. J. V. D. Pauw.  A METHOD OF MEASURING SPECIFIC RESISTIVITY AND HALL EFFECT OF DISCS OF ARBITRARY SHAPE , 1991 .

[47]  M. Wuttig,et al.  Charge transport in phase change materials , 2013 .

[48]  Kenneth F. Kelton,et al.  Structural Aspects of Metallic Glasses , 2007 .

[49]  D. Ielmini,et al.  Reliability Impact of Chalcogenide-Structure Relaxation in Phase-Change Memory (PCM) Cells—Part I: Experimental Study , 2009, IEEE Transactions on Electron Devices.

[50]  M. Wuttig,et al.  Electrical transport and switching in phase change materials , 2010 .

[51]  D. Ielmini,et al.  Physical interpretation, modeling and impact on phase change memory (PCM) reliability of resistance drift due to chalcogenide structural relaxation , 2007, 2007 IEEE International Electron Devices Meeting.

[52]  S. Lai,et al.  Current status of the phase change memory and its future , 2003, IEEE International Electron Devices Meeting 2003.

[53]  E. Eleftheriou,et al.  Drift-Tolerant Multilevel Phase-Change Memory , 2011, 2011 3rd IEEE International Memory Workshop (IMW).

[54]  I. Karpov,et al.  Fundamental drift of parameters in chalcogenide phase change memory , 2007 .

[55]  David Turnbull,et al.  Calorimetric studies of crystallization and relaxation of amorphous Si and Ge prepared by ion implantation , 1985 .

[56]  D. Ielmini,et al.  Physical mechanism and temperature acceleration of relaxation effects in phase-change memory cells , 2008, 2008 IEEE International Reliability Physics Symposium.

[57]  A. Pirovano,et al.  Low-field amorphous state resistance and threshold voltage drift in chalcogenide materials , 2004, IEEE Transactions on Electron Devices.