Raoux / Wuttig Phase Change Materials

Science and Applications
1. Auflage 2010
ISBN: 978-0-387-84874-7
Verlag: Springer
Format: PDF
Kopierschutz: 1 - PDF Watermark

E-Book, Englisch, 463 Seiten

'Phase Change Materials: Science and Applications' provides a unique introduction of this rapidly developing field. Clearly written and well-structured, this volume describes the material science of these fascinating materials from a theoretical and experimental perspective. Readers will find an in-depth description of their existing and potential applications in optical and solid state storage devices as well as reconfigurable logic applications. Researchers, graduate students and scientists with an interest in this field will find 'Phase Change Materials' to be a valuable reference.

Autoren/Hrsg.

Raoux, Simone

Wuttig, Matthias

Inhaltsverzeichnis

1;Foreword;5
2;Preface;8
3;Contents;10
4;Abbreviations;17
5;1. History of Phase Change Memories;21
5.1;1.1 The Discovery of Phase Change Materials;21
5.2;1.2 Early Electronic Computers and Memory Systems;22
5.3;1.3 Pioneers in Phase Change Memory;24
5.4;1.4 Early Attempts with Phase Change Memory;29
5.5;1.5 Rebirth of Phase Change Memory;30
5.6;References;34
6;Part I:Material Science: Theoryand Experiment;35
6.1;2. Density Functional Theory Calculations for Phase Change Materials;36
6.1.1;2.1 Introduction;36
6.1.2;2.2 The Theorem of Hohenberg and Kohn;37
6.1.3;2.3 The Kohn-Sham Equation;39
6.1.4;2.4 The Local Density Approximation;41
6.1.5;2.5 Beyond Density Functional Theory;42
6.1.6;2.6 Application of DFT in the Field of Phase Change Materials;43
6.1.6.1;2.6.1 Structure Determination;44
6.1.6.2;2.6.2 Electronic Properties;48
6.1.7;References;55
6.2;3. Nature of Glasses;58
6.2.1;3.1 Introduction;58
6.2.2;3.2 Thermodynamics of the Glass Transition;60
6.2.3;3.3 Glass Transition from Dynamics;62
6.2.4;3.4 Glass Forming Tendency;63
6.2.4.1;3.4.1 Compositional Trends of the Glass TransitionTemperature;65
6.2.5;3.5 Calorimetric Measurement of the Glass Transition Temperature and Related Thermal Properties;67
6.2.6;3.6 Three Generic Classifications of Glasses and Glass Transitions;70
6.2.7;3.7 Elastic Phases in Ionic and Super-ionic Glasses;73
6.2.8;3.8 Ideal Glasses and Self-organization of Networks;73
6.2.9;3.9 Does the View Below the Glass Transition Temperature Correlate with the View above the Glass Transition Temperature?;75
6.2.10;3. 10 Glass Formation in Hydrogen Bonded Networks;76
6.2.11;3.11 Epilogue;78
6.2.12;References;78
6.3;4. Structure of Amorphous Ge-Sb-Te Solids;82
6.3.1;4.1 Introduction;82
6.3.2;4.2 Structural Order in Amorphous Materials;83
6.3.2.1;4.2.1 Short-range Order;83
6.3.2.2;4.2.2 Medium-range Order;84
6.3.2.3;4.2.3 Long-range Structure;85
6.3.3;4.3 Experimental Structural Probes;86
6.3.4;4.4 Structural Modeling;87
6.3.5;4.5 The Structure of Amorphous Phase-change Materials;88
6.3.5.1;4.5.1 Experimental Studies;88
6.3.5.2;4.5.2 Simulational Studies;91
6.3.6;4.6 Summary;97
6.3.7;References;98
6.4;5. Experimental Methods for Material Selection in Phase-change Recording;100
6.4.1;5.1 Introduction;100
6.4.2;5.2 Reversible Switching;101
6.4.3;5.3 Phase-change Materials;103
6.4.3.1;5.3.1 Crystallization by Nucleation and Growth;105
6.4.3.2;5.3.2 Crystallization Dominated by Crystal Growth;107
6.4.4;5.4 Archival Life Stability;108
6.4.5;5.5 Crystallization Rate;110
6.4.6;5.6 Material Optimization;112
6.4.7;5.7 Outlook;116
6.4.8;References;117
6.5;6. Scaling Properties of Phase Change Materials;118
6.5.1;6.1 Introduction;118
6.5.2;6.2 Thin Films of Phase Change Materials;119
6.5.2.1;6.2.1 Crystallization Temperature as a Function of Film Thickness;120
6.5.2.2;6.2.2 Crystallization Rate as a Function of Film Thickness;124
6.5.2.3;6.2.3 Change in Optical Constants and Electrical and Thermal Parameters as a Function of Film Thickness;127
6.5.2.4;6.2.4 Limits of Storage Density in Thin Films;128
6.5.3;6.3 Phase Change Nanowires;130
6.5.4;6.4 Phase Change Nanoparticles;133
6.5.5;6.5 Scaling in Time – Switching Speed of Phase Change Materials;137
6.5.6;References;139
6.6;7. Crystallization Kinetics;144
6.6.1;7.1 Theory;144
6.6.1.1;7.1.1 Homogeneous Crystal Nucleation;144
6.6.1.1.1;7.1.1.1 Thermodynamics of Cluster Formation (Gibbs, 1878);145
6.6.1.1.2;7.1.1.2 Model Based on Equilibrium Distribution of Clusters (Volmer and Weber, 1926);146
6.6.1.1.3;7.1.1.3 Steady State Model (Becker and Döring, 1935);147
6.6.1.1.4;7.1.1.4 The Kinetic Pre-factor of the Nucleation Rate (Turnbull and Fisher, 1949);148
6.6.1.2;7.1.2 Heterogeneous Crystal Nucleation;152
6.6.1.3;7.1.3 Crystal Growth;154
6.6.1.3.1;7.1.3.1 Interface-controlled Growth;155
6.6.1.3.2;7.1.3.2 Growth Controlled by Long-range Diffusion;156
6.6.2;7.2 Measurements;157
6.6.2.1;7.2.1 Crystallization Parameters Around the Glass Transition Temperature;157
6.6.2.2;7.2.2 Crystallization Parameters Close to the Melting Temperature;161
6.6.3;References;164
6.7;8. Short and Long-Range Order in Phase Change Materials;168
6.7.1;8.1 Historical Background;168
6.7.1.1;8.1.1 Glass Formation Process;169
6.7.2;8.2 Long-Range Order;170
6.7.2.1;8.2.1 GeTe;171
6.7.2.2;8.2.2 Ge-Sb-Te Alloys;173
6.7.2.2.1;8.2.2.1 Metastable Ge-Sb-Te Alloys;173
6.7.2.2.2;8.2.2.2 High-Pressure Effects on Metastable Ge-Sb-Te Alloys;175
6.7.2.2.3;8.2.2.3 Ge-Sb-Te Equilibrium Structures;176
6.7.2.2.4;8.2.2.4 Sb-Te Alloys;177
6.7.3;8.3 Short-Range Order;179
6.7.3.1;8.3.1 X-ray Absorption;179
6.7.3.1.1;8.3.1.1 Short-range Order in Crystalline GeTe;183
6.7.3.1.2;8.3.1.2 Short-range Order in Amorphous GeTe;184
6.7.3.1.3;8.3.1.3 Short-range Order in Crystalline Ge2Sb2Te5;186
6.7.3.2;8.3.2 Short Range Order in Sb-Te Alloys;189
6.7.3.2.1;8.3.2.1 Conclusions;190
6.7.4;References;190
6.8;9. Optical and Electrical Properties of Phase Change Materials;194
6.8.1;9.1 Introduction;194
6.8.2;9.2 Optical Constants and Optical Bandgap;195
6.8.2.1;9.2.1 Determination of the Optical Constants and Absorption Coefficient;195
6.8.2.1.1;9.2.1.1 Transmission and Reflection Measurements;196
6.8.2.1.2;9.2.1.2 Ellipsometry;196
6.8.2.1.3;9.2.1.3 Optical Contrast between Amorphous and Crystalline Phases;197
6.8.2.2;9.2.2 Optical Bandgap;198
6.8.2.3;9.2.3 Infrared Absorption: Band Tails and Free Carrier Absorption;200
6.8.2.3.1;9.2.3.1 Urbach Edge;200
6.8.2.3.2;9.2.3.2 Free Carrier Absorption;201
6.8.2.4;9.2.4 Effects of Composition and Preparation Conditions;201
6.8.3;9.3 Photo-induced Effects;203
6.8.3.1;9.3.1 Photo-induced Current and Optical Nonlinearity;203
6.8.3.2;9.3.2 Photo-Oxidation;204
6.8.4;9.4 Conductivity and Phase Transformation;205
6.8.4.1;9.4.1 Temperature-dependence of Resistivity;205
6.8.4.2;9.4.2 Intermediate States: Percolation and Multilevel Recording;206
6.8.4.3;9.4.3 Effects of Composition and Processing Conditions;207
6.8.5;9.5 Electronic Transport Properties and Band Structure;208
6.8.5.1;9.5.1 Characterization of Transport Properties;208
6.8.5.1.1;9.5.1.1 Hall Measurements;208
6.8.5.1.2;9.5.1.2 Thermoelectric Effect;209
6.8.5.2;9.5.2 Hexagonal Ge2Sb2Te5;210
6.8.5.3;9.5.3 Face-centered-cubic Ge2Sb2Te5;212
6.8.5.4;9.5.4 Amorphous Ge2Sb2Te5;213
6.8.6;9.6 Perspective for the Future;213
6.8.7;References;214
6.9;10. Development of Materials for Third Generation Optical Storage Media;218
6.9.1;10.1 Introduction;218
6.9.2;10.2 Requirements for a Phase-change Material;219
6.9.3;10.3 Why Chalcogenide Semiconductors for Optical Memory?;221
6.9.4;10.4 Merits and Demerits of the Te Based Eutectic Alloys;222
6.9.5;10.5 Merits and Demerits of the Te-based Single Phase Materials;225
6.9.6;10.6 From Eutectic to Single Phase Compositions;227
6.9.7;10.7 Discovery of the GeTe-Sb2Te3 Pseudo-binary System;228
6.9.8;10.8 Importance of the Cubic Structure and Vacancies;232
6.9.9;10.9 Secrets of the Present Phase-change Materials I;234
6.9.10;10.10 Materials for Blue Laser and Multi-layer Applications;238
6.9.11;10.11 Secrets of Present Phase-change Materials II;241
6.9.12;10.12 Conclusions;242
6.9.13;References;243
6.10;11. Novel Deposition Methods;246
6.10.1;11.1 Chemical Vapor Phase Deposition;246
6.10.2;11.2 Electrodeposition;252
6.10.3;11.3 Solution-phase Deposition;257
6.10.4;11.4 Nanomaterials;260
6.10.5;11.5 Conclusions;262
6.10.6;References;263
7;Part II: Applications: Optical, Solid State Memory and Reconfigurable Logic;268
7.1;12. Optical Memory: From 1st to 3rd Generation and its Future;269
7.1.1;12.1 Introduction;269
7.1.2;12.2 Three Generations of Optical Media;270
7.1.2.1;12.2.1 The First Generation: Compact Discs (CDs);271
7.1.2.2;12.2.2 The Second Generation: Digital Versatile Disks (DVDs);271
7.1.2.3;12.2.3 The Third Generation: Blu-ray Discs (BDs);274
7.1.2.3.1;12.2.3.1 Blu-ray Discs;274
7.1.3;12.3 The Basic Principle of Optical Recording;275
7.1.4;12.4 Phase-change Optical Recording and Related Technologies;278
7.1.4.1;12.4.1 Phase-Change Optical Storage;278
7.1.4.1.1;12.4.1.1 Principle of Phase-Change Optical Storage;278
7.1.4.1.2;12.4.1.2 Phase-Change Materials;281
7.1.4.1.3;12.4.1.3 Development of Phase-Change Optical Storage Media;282
7.1.4.1.4;12.4.1.4 Disc Structure of Phase-Change Optical Disc;285
7.1.4.1.5;12.4.1.5 Models of Phase-Change Induced by Moving Laser Beam;287
7.1.4.2;12.4.2 Techniques for Phase-Change Optical Storage;288
7.1.4.2.1;12.4.2.1 Short Wavelength Laser Diodes;289
7.1.4.2.2;12.4.2.2 Large Numerical Aperture (NA);289
7.1.4.2.3;12.4.2.3 Land/Groove Recording;289
7.1.4.2.4;12.4.2.4 Write Strategy;290
7.1.4.2.5;12.4.2.5 Cross Talk;291
7.1.4.2.6;12.4.2.6 Super Resolution;292
7.1.4.2.7;12.4.2.7 Multilevel Phase-Change Recording;293
7.1.4.2.8;12.4.2.8 Dual Layer Phase-change Optical Recording;293
7.1.4.2.9;12.4.2.9 Superlattice-like Phase-change Optical Disc;294
7.1.4.2.10;12.4.2.10 Initialization Free Phase-change Optical Disc;295
7.1.4.2.11;12.4.2.11 Near-field Phase-Change Optical Storage;297
7.1.5;12.5 The Future of Optical Storage;297
7.1.6;References;300
7.2;13. 4th Generation Optical Memories Based on Super-resolution Near-field structure (Super-RENS) and Near-field Optics;303
7.2.1;13.1 Introduction;303
7.2.2;13.2 Diffraction Limit and Near-Field Optics;304
7.2.3;13.3 Small Aperture and Non-propagating Photons;306
7.2.4;13.4 Super-resolution Near-field Structure (Super-RENS) Principle to Retrieve Non-propagating Light;308
7.2.5;13.5 Origin of the Strong Scattered Signals for 4th Generation Super-RENS Disks;310
7.2.6;13.6 Beyond Super-RENS;314
7.2.7;References;315
7.3;14. Phase Change Memory Device Modeling;317
7.3.1;14.1 Introduction;317
7.3.2;14.2 Device Operation;318
7.3.3;14.3 Modeling of Electrical Conduction in the Amorphous Phase;320
7.3.4;14.4 Threshold Switching in the Amorphous Chalcogenide;324
7.3.5;14.5 Modeling the Electrical Conduction in the Crystalline Chalcogenide;326
7.3.6;14.6 Electro-thermal Modeling of the Programming Characteristics;327
7.3.7;14.7 Modeling the Amorphous to Crystalline Phase Transformation;332
7.3.8;14.8 Modeling the Structural Relaxation in the Amorphous Phase;338
7.3.9;14.9 Summary and Outlook;343
7.3.10;References;345
7.4;15. Phase Change Random Access Memory Advanced Prototype Devices and Scaling;348
7.4.1;15.1 Introduction;348
7.4.2;15.2 Device Scaling by Reducing the Electrode Contact Area;349
7.4.2.1;15.2.1 The Heater Structure;350
7.4.2.1.1;15.2.1.1 Additional Adhesion Layer;351
7.4.2.1.2;15.2.1.2 Size Effect of the Phase Change Material;352
7.4.2.1.3;15.2.1.3 Different Phase Change Materials;353
7.4.2.1.4;15.2.1.4 Process Integration Issues for Scaling;353
7.4.2.2;15.2.2 The Edge Contact Structure;354
7.4.2.3;15.2.3 ?Trench Structure;355
7.4.2.4;15.2.4 The Ring Structure;355
7.4.3;15.3 Device Scaling by Reducing the Phase Change Material Volume;356
7.4.3.1;15.3.1 The Pillar Structure;357
7.4.3.2;15.3.2 The Line Structure;358
7.4.3.3;15.3.3 The Bridge Structure;359
7.4.4;15.4 Other Prototype Devices;360
7.4.4.1;15.4.1 Scaling Both the Material and the Contact;361
7.4.4.2;15.4.2 Multi-level Cell;362
7.4.4.3;15.4.3 Confined Structure;362
7.4.5;15.5 Advanced Device Testing;364
7.4.6;15.6 Summary;366
7.4.7;References;367
7.5;16. Phase Change Memory Cell Concepts and Designs;372
7.5.1;16.1 Introduction;372
7.5.2;16.2 Technology Overview;373
7.5.3;16.3 Phase Change Memory Cell Electrical Characterization;378
7.5.4;16.4 Phase Change Memory Cell Reliability;385
7.5.4.1;16.4.1 Data Retention Characterization;386
7.5.4.2;16.4.2 Retention Behavior with Device Scaling;393
7.5.4.3;16.4.3 Cycling Endurance;394
7.5.5;16. 5 Summary and Outlook;395
7.5.6;References;396
7.6;17. Phase Change Random Access Memory Integration;398
7.6.1;17.1 Introduction;398
7.6.2;17.2 Phase Change Random Access Memory Design Basics;399
7.6.3;17.3 Review of Desired Phase Change Memory CellCharacteristics;403
7.6.4;17.4 The Access Device;407
7.6.5;17.5 Device Design Considerations;410
7.6.5.1;17.5.1 The Mushroom Cell without or with Bottom RingElectrode;410
7.6.5.2;17.5.2 The Pillar Cell;414
7.6.5.3;17.5.3 The ?Trench Cell;416
7.6.5.4;17.5.4 The Pore Cell;416
7.6.6;17.6 Multi-Level Phase Change Random Access Memory;420
7.6.7;17.7 Concluding Remarks;423
7.6.8;References;423
7.7;18. Reconfigurable Logic;426
7.7.1;18.1 Introduction;426
7.7.2;18.2 Digital System Basics;427
7.7.3;18.3 Simple Configurable Digital Systems;431
7.7.4;18.4 Considerations in Computation Architectures;436
7.7.5;18. 5 Multi-valued Systems;437
7.7.6;18.6 Threshold Logic;439
7.7.7;18.7 Artificial Neural Networks;442
7.7.8;18.8 Other Analog-domain Programmable Systems;443
7.7.9;18.9 Conclusions;446
7.7.10;References;446
8;Author Bios;448
9;Index;454