Preface xi
Acknowledgments xv
1 Introduction to Gallium Nitride Properties and Applications 1
Fabrizio Roccaforte and Mike Leszczynski
1.1 Historical Background 1
1.2 Basic Properties of Nitrides 4
1.2.1 Microstructure and Related Issues 7
1.2.2 Optical Properties 13
1.2.3 Electrical Properties 16
1.2.4 Two-Dimensional Electron Gas (2DEG) in AlGaN/GaN Heterostructures 19
1.3 Applications of GaN-Based Materials 23
1.3.1 Optoelectronic Devices 24
1.3.2 Power- and High-Frequency Electronic Devices 26
1.4 Summary 30
Acknowledgments 31
References 31
2 GaN-Based Materials: Substrates, Metalorganic Vapor-Phase Epitaxy, and Quantum Well Properties 41
Ferdinand Scholz, Michal Bockowski, and Ewa Grzanka
2.1 Introduction 41
2.2 Bulk GaN Growth 42
2.2.1 Hydride Vapor-Phase Epitaxy (HVPE) 43
2.2.2 Sodium Flux Growth Method 45
2.2.3 Ammonothermal Growth 46
2.3 MOVPE Growth 51
2.3.1 Basics About Nitride MOVPE 54
2.3.2 Epitaxy on Foreign Substrates 58
2.3.2.1 Sapphire as a Foreign Substrate 58
2.3.2.2 GaN on SiC and Si 60
2.3.3 Defect Reduction by ELOG, FACELO, etc. 62
2.3.4 In Situ ELOG by SiN Deposition 64
2.3.5 Doping of Nitrides 64
2.3.6 Growth of Other Binary and Ternary Nitrides 67
2.4 InGaN QWs: Growth and Decomposition 72
2.4.1 Growth of InGaN QWs on Polar, Nonpolar, and Semipolar GaN Substrates 72
2.4.2 Origins of In Fluctuations 75
2.4.3 Homogenization of InGaN QWs 78
2.4.4 Decomposition of the QWs 79
2.5 Summary 82
Acknowledgments 82
References 83
3 GaN-Based HEMTs for Millimeter-wave Applications 99
Kathia Harrouche and Farid Medjdoub
3.1 Introduction 99
3.2 Targeted Applications for GaN Millimeter-wave Devices 99
3.2.1 High-Power Amplification 100
3.2.2 Broadband Amplifiers 102
3.2.3 5G 103
3.2.3.1 GaN for 5G 104
3.2.3.2 GaN Base Station PAs 106
3.2.3.3 Moving Forward to 6G 108
3.3 GaN-based Material Designs for Millimeter-wave Applications 108
3.3.1 Intrinsic Characteristics and Comparison with Other Materials for RF Devices 108
3.3.2 Specific Material Systems for RF Devices 114
3.4 Device Design and Fabrication of Millimeter-wave GaN Devices 116
3.4.1 Description of Key Processing Steps for Various GaN Device Designs 116
3.4.1.1 Device Scaling for Millimeter Wave 116
3.4.1.2 T-shaped Gate Design 116
3.4.1.3 Advanced Ohmic Contact Technology 117
3.4.1.4 N-polar GaN HEMTs 118
3.4.1.5 AlN-Based Device Performances 119
3.4.1.6 InAlGaN-Based Device Performances 121
3.4.2 State-of-the-art Millimeter-wave GaN Transistors 122
3.5 Overview of MMIC Power Amplifiers 123
3.5.1 MMIC Technology Using III-N Devices 123
3.5.1.1 IIIâ"V Material-Based MMIC Technology 123
3.5.1.2 Power Amplifiers 124
3.5.1.3 Low-Noise Amplifier 125
3.5.2 MMIC Examples from Ka-band to D-band Frequencies 125
3.6 Summary 126
References 127
4 Technologies for Normally-off GaN HEMTs 137
Giuseppe Greco, Patrick Fiorenza, Ferdinando Iucolano, and Fabrizio Roccaforte
4.1 Introduction 137
4.1.1 Threshold Voltage in AlGaN/GaN HEMTs 138
4.2 GaN HEMT âCascodeâ 140
4.3 âTrueâ Normally-off HEMT Technologies 142
4.3.1 Recessed-gate HEMT 142
4.3.2 Fluorinated HEMT 145
4.3.3 Recessed-gate Hybrid MISHEMT 149
4.3.4 p-GaN Gate HEMT 155
4.4 Other Approaches 163
4.5 Summary 164
Acknowledgments 165
References 165
5 Vertical GaN Power Devices 177
Srabanti Chowdhury and Dong Ji
5.1 Introduction 177
5.2 Vertical GaN Devices for Power Conversion 177
5.3 Vertical GaN Transistors 178
5.3.1 Current Aperture Vertical Electron Transistor (CAVET) 178
5.3.2 Vertical MOSFETs 182
5.4 High-Voltage Diodes in GaN 185
5.5 Avalanche Electroluminescence in GaN Pâ"N Diodes 186
5.6 Impact Ionization Coefficients in GaN 188
5.6.1 Impact of Impact Ionization Studies on Predictive Modeling 193
5.7 Summary 193
Acknowledgments 193
References 194
6 Reliability Issues in GaN Electronic Devices 199
Milan apajna and Christian Koller
6.1 Introduction 199
6.1.1 Reliability Testing and Failure Analysis of GaN HEMTs 200
6.2 Reliability of GaN HEMTs for RF Applications 204
6.2.1 AlGaN/GaN HEMTs 204
6.2.1.1 Trapping Effects 204
6.2.1.2 Gate-edge Degradation 207
6.2.1.3 Hot Electron Degradation 209
6.2.2 InAlN/GaN HEMTs 211
6.2.2.1 Hot Electron Degradation 212
6.2.2.2 Role of Hot Phonons 214
6.2.3 Thermal Issues in RF GaN HEMTs 215
6.3 Reliability and Robustness of GaN Power Switching Devices 219
6.3.1 Parasitic Effects in the Carbon-Doped GaN Buffer 221
6.3.1.1 Insulation of GaN Buffer by Carbon Doping 221
6.3.1.2 Time-Dependent âDielectricâ Breakdown (TDDB) of the GaN Buffer 223
6.3.1.3 Dynamic RDS,ON Due to Buffer Trapping 225
6.3.2 Gate Degradation in p-GaN Switching HEMTs 230
6.3.3 Vth Instabilities in GaN MISHEMTs 233
6.3.3.1 Studies of PBTI in MISHEMTs 237
6.4 Summary 241
Acknowledgments 241
References 241
7 Light-Emitting Diodes 253
Amit Yadav, Hideki Hirayama, and Edik U. Rafailov
7.1 Introduction 253
7.2 State-of-the-Art GaN LEDs 254
7.2.1 Blue LEDs 258
7.2.2 Green LEDs 262
7.3 GaN White LEDs: Approaches and Properties 264
7.3.1 Monolithic LEDs 267
7.3.2 Phosphor-Covered LEDs 271
7.4 AlGaN Deep UV LEDs 275
7.4.1 Growth of High-Quality AlN and Increasing in Internal Quantum Efficiency (IQE) 278
7.4.2 AlGaN-based UVC LEDs 281
7.4.3 Increasing the Light Extraction Efficiency (LEE) 282
7.5 Summary 287
Acknowledgments 288
References 288
8 Laser Diodes Grown by Molecular Beam Epitaxy 301
Greg Muziol, Henryk Turski, Marcin Siekacz, Marta Sawicka, and Czeslaw Skierbiszewski
8.1 Introduction 301
8.2 III-N Growth Fundamentals by Plasma-Assisted MBE 303
8.2.1 Role of N-Flux for Efficient InGaN QWs 304
8.3 Wide InGaN QWs â" Beyond Quantum-Confined Stark Effect 305
8.4 Long-Living Laser Diodes on Bulk Ammono-GaN 313
8.5 Laser Diodes with Tunnel Junctions 316
8.5.1 Stacks of Vertically Interconnected Laser Diodes 319
8.5.2 Distributed Feedback Laser Diodes 321
8.6 Summary 324
Acknowledgments 324
References 325
9 Edge Emitting Laser Diodes and Superluminescent Diodes 333
Szymon Stanczyk, Anna Kafar, Dario Schiavon, Stephen Najda, Thomas Slight, and Piotr Perlin
9.1 Laser Diode: History and Development 333
9.1.1 Optoelectronics Background 333
9.1.2 Gallium Nitride Technology Breakthroughs 335
9.1.3 Development of Nitride Laser Diodes 337
9.2 Distributed Feedback Laser Diodes 342
9.3 Superluminescent Diodes 348
9.3.1 History of Superluminescent Diode Development 348
9.3.2 Basic SLD Properties 351
9.3.3 Challenges for SLD Optimization 353
9.4 Semiconductor Optical Amplifiers 354
9.5 Summary 357
References 358
10 Green and Blue Vertical-Cavity Surface-Emitting Lasers 367
Yang Mei, Rong-Bin Xu, Huan Xu, and Bao-Ping Zhang
10.1 Introduction 367
10.1.1 Properties and Application of GaN VCSELs 367
10.1.2 Brief History and Current Status of GaN VCSELs 368
10.1.3 GaN VCSELs with Different DBRs 369
10.1.3.1 GaN VCSELs with Hybrid DBR Structure 370
10.1.3.2 GaN VCSELs with Double Dielectric DBR Structure 371
10.2 Efficiency of Heat Dissipation of Different Device Structures 372
10.2.1 Simulation of Heat Profile of the Device 372
10.2.2 Dependence of Rth on Cavity Length 373
10.3 Green VCSELs Based on InGaN QDs 375
10.3.1 Advantages of QDs Compared with QWs 375
10.3.2 Growth and Optical Properties of InGaN QDs 377
10.3.3 Fabrication Process of VCSELs 379
10.3.4 Properties of QD Green VCSELs 379
10.4 Green VCSELs Based on Cavity-Enhanced Emission of Localized States in Blue Emitting InGaN QWs 380
10.4.1 Cavity Effect 380
10.4.2 Properties of Cavity-Enhanced Green VCSELs 381
10.5 Dual-Wavelength Lasing Based on QD-in-QW Active Structure 384
10.5.1 Characteristics of QD-in-QW Structure 384
10.5.2 Lasing Characteristics of VCSELs 386
10.6 Blue VCSELs with Different Lateral Confinements 386
10.6.1 Design of Index-Guided Structure 386
10.6.2 Emission Properties of VCSELs with Lateral Confinement 388
10.7 Summary 389
References 390
11 Integration of 2DMaterials with Nitrides for Novel Electronic and Optoelectronic Applications 397
Filippo Giannazzo, Emanuela Schilir², Raffaella Lo Nigro, Pawel Prystawko, and Yvon Cordier
11.1 Introduction 397
11.2 Fabrication of 2D Material Heterostructures with Nitride Semiconductors 400
11.2.1 Transfer of 2D Materials Grown on a Foreign Substrate 400
11.2.2 Direct Growth of 2D Materials on Group III-Nitrides 403
11.2.3 2D Materials as Templates for the Growth of Nitride Semiconductor Films 407
11.3 Electronic Devices Based on 2D Materials/GaN Heterojunctions 413
11.3.1 Band-to-band Tunneling Diodes Based on MoS2/GaN Heterojunctions 413
11.3.2 Hot Electron Transistors with Graphene Base and Al(Ga)N/GaN Emitter 414
11.4 Optoelectronic Devices Based on 2D Material Junctions with GaN 421
11.4.1 GaN LEDs with Graphene-Transparent Conductive Electrodes 421
11.4.2 MoS2/GaN Deep UV Photodetectors 427
11.5 Applications of Graphene for Thermal Management in GaN HEMTs 428
11.6 Summary 431
Acknowledgments 431
References 432
Index 439
