Table of Contents
Preface Emmanuel Defaÿ xiii
Chapter 1 The Thermodynamic Approach Emmanuel Defaÿ 1
1.1 Background 1
1.2 The functions of state 2
1.3 Linear equations, piezoelectricity 6
1.4 Nonlinear equations, electrostriction 8
1.5 Thermodynamic modeling of the ferroelectric-paraelectric phase transition 9
1.5.1 Assumption on the elastic Gibbs energy 9
1.5.2 Second-order transition 12
1.5.3 Effect of stress 18
1.5.4 First-order transition 20
1.6 Conclusion 24
1.7 Bibliography 25
Chapter 2 Stress Effect on Thin Films Pierre-Eymeric Janolin 27
2.1 Introduction 27
2.2 Modeling the system under consideration 27
2.3 Temperature-misfit strain phase diagrams for monodomain films 28
2.3.1 Phase diagram construction from the Landau-Ginzburg-Devonshire theory 29
2.3.2 Calculations limitations 34
2.4 Domain stability map 35
2.4.1 Presentation and description of the framework of study 36
2.4.2 Main contributions to the total energy of a film 36
2.4.3 Influence of thickness 39
2.4.4 Macroscopic elastic energy for each type of tetragonal domain 39
2.4.5 Indirect interaction energy 40
2.4.6 Domain structures at equilibrium 42
2.4.7 Domain stability map 43
2.5 Temperature-misfit strain phase diagram for polydomain films 48
2.6 Discussion of the nature of the "misfit strain" 50
2.6.1 Mechanical misfit strain 50
2.6.2 Thermodynamic misfit strain 51
2.6.3 As an illustration 51
2.7 Conclusion 52
2.8 Experimental validation of phase diagrams: state of the art 52
2.9 Case study 53
2.10 Results 53
2.10.1 Evolution of the lattice parameters 53
2.10.2 Associated stresses and strains 56
2.11 Comparison between the experimental data and the temperature-misfit strain phase diagrams 60
2.11.1 Thin film of PZT 60
2.11.2 Thin layer of PbTiO3 63
2.12 Conclusion 65
2.13 Bibliography 66
Chapter 3 Deposition and Patterning Technologies Chrystel Deguet Gwenaël Le Rhun Bertrand Vilquin Emmanuel Defaÿ 71
3.1 Deposition method 71
3.1.1 Cathodic sputtering 71
3.1.2 Ion beam sputtering 74
3.1.3 Pulsed laser deposition 75
3.1.4 The sol-gel process 77
3.1.5 The MOCVD 79
3.1.6 Molecular beam epitaxy 81
3.2 Etching 86
3.2.1 Wet etching 86
3.2.2 Dry etching 86
3.3 Contamination 86
3.4 Monocrystalline thin-film transfer 87
3.4.1 Smart Cut™ technology 88
3.4.2 Bonding/thinning 89
3.4.3 Interest in the material in a thin layer 91
3.4.4 State of the art of the domain/applications 91
3.4.5 An exemplary implementation 94
3.5 Design of experiments 96
3.5.1 The assumptions 97
3.5.2 Reproducibility 99
3.5.3 How can we reduce the number of experiments? 100
3.5.4 A DOE example: PZT RF magnetron sputtering deposition 102
3.6 Conclusion 107
3.7 Bibliography 108
Chapter 4 Analysis Through X-ray Diffraction of Polycrystalline Thin Films Patrice Gergaud 111
4.1 Introduction 111
4.2 Some reminders of x-ray diffraction and crystallography 112
4.2.1 Nature of X-rays 112
4.2.2 X-ray scattering and diffraction 113
4.3 Application to powder or polycrystalline thin-films 122
4.4 Phase analysis by X-ray diffraction 126
4.4.1 Grazing incidence diffraction 128
4.4.2 De-texturing 131
4.4.3 Quantitative analysis 131
4.5 Identification of coherent domain sizes of diffraction and micro-strains 132
4.5.1 Analysis methodologies 134
4.6 Identification of crystallographic textures by X-ray diffraction 139
4.6.1 Texture analysis by a symmetric diffractogram 140
4.6.2 Pole figures and orientations distribution function 143
4.6.3 Measurement principle 143
4.6.4 Orientations distribution function 144
4.7 Determination of strains/stresses by X-ray diffraction 146
4.7.1 X-ray diffraction and strain 146
4.7.2 Determination of stresses from strains 148
4.7.3 Specificity of the X-ray diffraction in stress analysis 151
4.7.4 Equipment 153
4.7.5 Example of stress identification by the sin2ψ method 154
4.7.6 Precaution in the case of thin films 154
4.7.7 Application example for a BaxTiO3 film 155
4.8 Bibliography 156
Chapter 5 Physicochemical and Electrical Characterization Gwenaël Le Rhun Brahim Dkhil Pascale Gemeiner 159
5.1 Introduction 159
5.2 Useful characterization techniques 159
5.2.1 Electron microscopy 160
5.2.2 Spectroscopy analysis 162
5.3 Ferroelectric measurement 170
5.3.1 Sawyer-Tower assembly 171
5.3.2 "Virtual ground" assembly 173
5.4 Dielectric measurement 177
5.5 Bibliography 180
Chapter 6 Radio-Frequency Characterization Thierry Lacrevaz 183
6.1 Introduction 183
6.2 Notions and basic concepts associated with HF 184
6.2.1 Introduction to the phenomena associated with HF signals 184
6.2.2 Lumped or distributed behavior of an electric circuit 186
6.2.3 Notion of quadripoles: two-port circuits or four-terminal network [MÉS 85] 187
6.2.4 Basic theoretical elements of transmission lines: HF electric model 191
6.2.5 HF electric model of a parallel MIM capacitor 195
6.2.6 Signal flow graph [BOR 93] 197
6.2.7 Scattering waves 198
6.2.8 Scattering parameters: S-parameters 199
6.2.9 Vector network analyzer (VNA) 202
6.3 Frequency analysis: HF characterization of materials 204
6.3.1 Objectives 204
6.3.2 Issues of HF measurements through a VNA 204
6.3.3 Calibration of the measuring system 206
6.3.4 Extraction of the propagation exponent of the transmission line: de-embedding associated with the TRL calibration 208
6.3.5 Extraction results of the complex permittivity of materials SrTiO3andPbZrTiO3 210
6.4 Bibliography 211
Chapter 7 Leakage Currents in PZT Capacitors Emilien Bouyssou 213
7.1 Introduction 213
7.2 Leakage current in metal/insulator/metal structures 215
7.2.1 Metal/insulator contact: definitions 215
7.2.2 Conduction mechanisms limited by the interfaces 219
7.2.3 Conduction mechanisms limited by the bulk of film 222
7.3 Problem of leakage current measurement 225
7.3.1 Relaxation current and true leakage current 226
7.3.2 Drift of true leakage current 230
7.3.3 Discussion 232
7.4 Characterization of the relaxation current 233
7.4.1 Origin of the relaxation current 233
7.4.2 Modeling of relaxation currents 234
7.4.3 Conclusion 237
7.5 Literature review of true leakage current in PZT 237
7.6 Dynamic characterization of true leakage current: I(t, T) 239
7.6.1 Study of the resistance degradation 241
7.6.2 Study of the resistance restoration phenomenon 256
7.6.3 Conclusion 262
7.7 Static characterization of the true leakage current: I(V,T) 263
7.7.1 Space-charge influenced-injection model 263
7.7.2 Quantitative description of the model 264
7.7.3 Static modeling Jmin(V) and Jmax(V) 267
7.8 Conclusion 273
7.9 Bibliography 275
Chapter 8 Integrated Capacitors Emmanuel Defaÿ 281
8.1 Introduction 281
8.2 Potentiality of perovskites for RF devices: permittivity and losses 283
8.2.1 RF MTM capacitors of STO and PZT 284
8.2.2 Coplanar line waveguides on PZT 288
8.2.3 How to perform a good integrated capacitor at RF frequencies? 292
8.3 Bi-dielectric capacitors with high linearity 294
8.3.1 Introduction 294
8.3.2 Design 295
8.3.3 Technology 296
8.3.4 Results 296
8.4 STO capacitors integrated on CMOS substrate by AIC technology 298
8.4.1 Introduction 298
8.4.2 Technology 298
8.4.3 Electrical tests 301
8.4.4 Conclusion 303
8.5 Bibliography 303
Chapter 9 Reliability of PZT Capacitors Emilien Bouyssou 305
9.1 Introduction 305
9.2 Accelerated aging of metal/insulator/metal structures 307
9.2.1 The electrical stresses 307
9.2.2 The breakdown 310
9.2.3 Statistical treatment of breakdown 312
9.3 Accelerated aging of PZT capacitors through CVS tests 316
9.3.1 Literature review 316
9.3.2 Statistical study of time-to-breakdown data 318
9.3.3 Discussion: characterization strategy 320
9.4 Lifetime extrapolation of PZT capacitors 325
9.4.1 Determination of the temperature acceleration factor 325
9.4.2 Determination of voltage acceleration 327
9.5 Conclusion 335
9.6 Bibliography 336
Chapter 10 Ferroelectric Tunable Capacitors Benoit Guigues 341
10.1 Introduction 341
10.2 Overview of the tunable capacitors 342
10.2.1 Applications requiring a tunable element 342
10.2.2 The tunable capacitors 343
10.2.3 Which material to choose? 350
10.3 Types of actual tunable capacitors 355
10.3.1 MTM capacitor 355
10.3.2 Planar capacity 363
10.3.3 Anisotropy effects 364
10.4 Toward new tunable capacitors 366
10.4.1 Composite ferroelectric materials 366
10.4.2 Hybrid tunable capacitor 372
10.5 Bibliography 375
Chapter 11 FRAM Ferroelectric Memories: Basic Operations, Limitations, Innovations and Applications Christophe Muller 379
11.1 Taxonomy of non-volatile memories 379
11.1.1 Present and future solutions 379
11.1.2 Difficult penetration of a highly competitive market 381
11.2 FRAM memories: basic operations and limitations 383
11.2.1 Charge storage in a ferroelectric capacitor 383
11.2.2 Ferroelectric materials 384
11.3 Technologies available in 2011 387
11.4 Technological innovations 388
11.4.1 3D ferroelectric capacitors 3 89
11.4.2 Ferroelectric field effect transistors 391
11.4.3 What about ferroelectric polymers? 393
11.5 Some application areas of FRAM technology 394
11.5.1 An alternative to EEPROM memories 394
11.5.2 Ferroelectric devices for RFID systems 395
11.6 Conclusion 396
11.7 Bibliography 397
Chapter 12 Integration of Multiferroic BiFeO3 Thin Films into Modern Microelectronics Xiaohong Zhu 403
12.1 Introduction 403
12.2 Preparation methods 407
12.2.1 Pulsed laser deposition 408
12.2.2 Chemical solution deposition 411
12.2.3 RF magnetron sputtering 414
12.3 Ferroelectricity and magnetism 416
12.3.1 Ferroelectricity 416
12.3.2 Magnetism 422
12.3.3 Magnetoelectric coupling 424
12.4 Device applications 427
12.4.1 Non-volatile ferroelectric memories 427
12.4.2 Spintronics 428
12.4.3 Terahertz radiation 432
12.4.4 Switchable ferroelectric diodes and photovoltaic devices 433
12.5 Bibliography 436
List of Authors 443
Index 445
