Nitride Semiconductors: Handbook on Materials and Devices

Nitride Semiconductors Handbook on Materials and Devices......Page 4
Contents......Page 8
Preface......Page 20
List of Contributors......Page 22
Part 1 Material......Page 26
1 High-Pressure Crystallization of GaN......Page 28
1.1 Introduction......Page 29
1.2.1 Thermodynamics – Properties of GaN-Ga-N(2) System......Page 30
1.2.2 Dissolution Kinetics of N(2) and Crystal Growth Mechanism......Page 33
1.2.3 What Happens with GaN at High Temperature when the N(2) Pressure is too Low?......Page 37
1.2.4 Crystallization of GaN Using High Nitrogen Pressure Solution Growth (HNPSG) Method – Experimental......Page 38
1.2.5.1 Crystals Grown without Intentional Seeding......Page 39
1.2.5.2 Seeded Growth of GaN by HNPS Method......Page 43
1.2.6.1 Point Defects......Page 46
1.2.6.2 Extended Defects......Page 49
1.3.2 Metalorganic Chemical Vapor Epitaxy on GaN Substrates in HPRC Unipress......Page 51
1.3.3 Molecular Beam Epitaxy......Page 57
1.4.2 Light Emitting Diodes Fabricated on Bulk GaN in HPRC......Page 60
1.4.3 Laser Diode Structures......Page 61
1.5 Conclusions......Page 65
1.7 References......Page 66
2 Epitaxial Lateral Overgrowth of GaN......Page 70
2.1.1 Introduction......Page 71
2.1.2.1 2D Growth Mode (GaN/Sapphire)......Page 73
2.1.2.2 3D Growth Mode (GaN/Sapphire)......Page 74
2.1.3.1 Extended Defects......Page 76
2.1.3.3 Defect-Related Optical Properties......Page 77
2.1.3.5 Electronic Properties of Defects......Page 79
2.2.2 Rationale......Page 81
2.2.3 Experimental......Page 83
2.3.1.1 Morphology and Defects......Page 84
2.3.1.2 Structural Assessment......Page 88
2.3.1.3 Kinetics......Page 89
2.3.1.4 In-Depth Optical Assessment of MOVPE ELO GaN......Page 90
2.3.2 HVPE......Page 91
2.3.2.1 In-Depth Assessment of HVPE ELO GaN......Page 92
2.3.2.2 Stripe Openings along <1120>......Page 93
2.3.2.4 (C(2)H(5))(2)GaCl as Ga Source......Page 97
2.3.2.5 Stress Generation......Page 98
2.3.3 Sublimation......Page 99
2.3.4.3 Maskless ELO......Page 100
2.3.5 Improvements of the Standard ELO Method......Page 101
2.3.6 Pendeo-Epitaxy......Page 102
2.4.1 Experimental (MOVPE)......Page 105
2.4.2.1 Cathodoluminescence......Page 109
2.4.2.2 Luminescence of GaN by Epitaxial Lateral Overgrowth......Page 113
2.4.2.4 Deep Level Transient Spectroscopy (DLTS)......Page 114
2.4.2.5 Strain Distribution......Page 115
2.4.3 Assessment of HVPE......Page 116
2.4.4 ELO and Yellow Luminescence......Page 118
2.5.1 3S-ELO......Page 120
2.5.2 Further Improvements......Page 121
2.6 Theoretical Analysis of ELO......Page 122
2.7 Acknowledgments......Page 123
2.8 References......Page 124
3 Plasma-Assisted Molecular Beam Epitaxy of III–V Nitrides......Page 132
3.1 Introduction......Page 133
3.2.1 The Different Sources......Page 134
3.2.2 The Nitrogen Plasma......Page 136
3.2.3 Characterization of the HD25 RF Source by Optical Emission Spectroscopy......Page 140
3.2.4 Which is the Best Source?......Page 143
3.3.1 Structure of the GaN {0001} Surfaces......Page 145
3.3.2 GaN Substrate Preparation......Page 152
3.3.3.1 Growth Chemistry......Page 156
3.3.3.3 Ga Adsorption and Desorption......Page 157
3.3.3.4 Growth Rates as a Function of III and V Fluxes......Page 159
3.3.3.5 The GaN Growth Regimen – a Phase Diagram......Page 160
3.3.4 Characteristics and Optimization of the (0001) GaN Growth......Page 165
3.3.4.1 Description of RFMBE Experiments......Page 166
3.3.4.2 Characterization of Materials Properties......Page 167
3.3.4.4 Conclusions......Page 170
3.3.5 Doping of GaN......Page 171
3.4.1 Substrates for PAMBE GaN Heteroepitaxy......Page 173
3.4.2 Important Issues in the Heteroepitaxy of GaN-on-Al(2)O(3) (0001)......Page 174
3.4.3.2 Observation and Analysis of Interfacial Defect Content......Page 176
3.4.4 Effect of Al(2)O(3) Nitridation on the Polarity and Microstructure of GaN Epilayers......Page 181
3.4.5 Conclusions......Page 187
3.5.1 Growth Model for Ternary III-Nitrides......Page 188
3.5.2 InGaN......Page 190
3.5.2.1 Phase Separation and Ordering of InGaN......Page 191
3.5.2.2 Effect of Atomic Hydrogen on the Incorporation of In......Page 192
3.5.3 AlGaN......Page 194
3.5.3.2 UV Detectors......Page 196
3.5.4 GaN/AlGaN MQWs for Intersubband Transitions......Page 199
3.5.4.1 Electron Scattering Time between Subbands......Page 203
3.5.5 AlGaN/GaN Heterostructures for Electronic Devices......Page 204
3.5.5.1 AlGaN/GaN HFETs......Page 205
3.6 Conclusions and Perspectives......Page 206
3.8 References......Page 207
4 Growth of Gallium Nitride by Hydride Vapor Phase Epitaxy......Page 218
4.1.1 Introduction......Page 219
4.1.2 Principle of HVPE......Page 220
4.1.3 Use of HVPE......Page 221
4.1.4 Problems Associated with GaN Growth......Page 222
4.2 Thermodynamical Study......Page 223
4.2.1 Thermodynamical Characteristics......Page 224
4.2.2 Partition Functions of the Molecules......Page 227
4.2.3 Calculation of the Partial Pressures......Page 230
4.2.4 Thermodynamical Study of the GaN Deposit......Page 231
4.3.1 Introduction......Page 232
4.3.2 Relations Between the {001} GaAs and (00.1) GaN Epitaxy......Page 233
4.3.3 Statistical Treatment of the Dynamic Equilibrium Surface-Vapor Phase......Page 234
4.3.4 Mass-Transfer Phase......Page 240
4.3.5 Crystal Growth Phase......Page 241
4.3.5.1 H(2) Growth Mechanism......Page 242
4.3.5.2 GaCl(3) Growth Mechanism......Page 244
4.3.6 Search for the Model Parameters......Page 245
4.3.7 Search for the Mass Transfer and Parasitic Nucleation Effects......Page 249
4.3.8.1 Experimental Results......Page 252
4.3.8.2 Third Growth Mechanism......Page 255
4.3.9 Discussion......Page 256
4.4 Results......Page 258
4.6 References......Page 261
5 Growth and Properties of InN......Page 266
5.1 Introduction......Page 267
5.2.1 Introduction......Page 269
5.2.2.1 Role of Different Nitrogen Species in PAMBE......Page 270
5.2.2.2 Maintenance of Stoichiometric Conditions During InN Growth by PAMBE......Page 271
5.2.3.1 Growth and Epilayer Morphology......Page 273
5.2.3.2 Interface with Sapphire, XRD Characterization and Hall Measurements......Page 276
5.2.4 Summary......Page 281
5.3.2 MOMBE as a Growth Technique for InN......Page 282
5.3.3.3 Nitridation......Page 283
5.3.4.1 Influence of Growth Temperature......Page 284
5.3.4.2 Influence of V/III Ratio......Page 285
5.3.5.1 Raman Measurements......Page 288
5.3.5.3 Hall Measurements......Page 289
5.4.1 Introduction......Page 290
5.4.2 Experimental......Page 291
5.4.3 Surface Morphology and Growth Rate of MOVPE InN......Page 292
5.4.4 Electrical Properties of MOVPE InN......Page 295
5.5.1 Introduction......Page 299
5.5.2.1 First-Order Raman Scattering......Page 300
5.5.2.2 Phonon Dispersion in InN......Page 303
5.5.3.1 Characterization of Samples......Page 305
5.5.3.2 Absorption and Luminescence in InN......Page 306
5.5.3.3 Luminescence and Absorption of Crystals with High Electron Concentrations......Page 307
5.5.3.5 Concentration Dependence of PL Band and Absorption Coefficient......Page 309
5.5.3.6 Photoluminescence Excitation and Photomodulated Reflectance Spectra......Page 310
5.5.3.7 Optical Spectra of In(x)Ga(1–x)N Layers......Page 311
5.5.3.8 Wide-Gap InN-based Samples......Page 312
5.5.3.9 Postgrowth Treatment of InN Samples......Page 313
5.5.4 Summary......Page 314
5.7 Acknowledgments......Page 315
5.8 References......Page 316
6.1 Introduction......Page 320
6.2.1 Thermodynamic Equilibrium......Page 321
6.3.1 Nonpolar Surfaces......Page 324
6.3.1.1 Wurtzite GaN (1100)......Page 325
6.3.1.3 Cubic GaN (110)......Page 326
6.3.1.4 General Trends......Page 327
6.3.2.1 GaN (001) Surface......Page 328
6.3.3 Polar Wurtzite Surfaces......Page 331
6.3.3.1 GaN (0001) Surface......Page 332
6.3.3.2 GaN (0001) Surface......Page 333
6.3.3.3 GaN (1101) Surface......Page 335
6.3.4.1 General Trends......Page 336
6.3.4.2 Comparison with Traditional Semiconductors......Page 337
6.4 Adatom Kinetics......Page 338
6.4.1 Diffusion of Adatoms on Equilibrium GaN Surfaces......Page 339
6.5 Consequences for Growth......Page 340
6.6 Acknowledgments......Page 341
6.7 References......Page 342
Part 2 Defects and Interfaces......Page 344
7.1 Introduction......Page 346
7.2.1 Defect Characterization by a Volterra-like Approach......Page 349
7.2.2 Defect Characterization by Circuit Mapping......Page 351
7.2.2.1 Circuits in Perfect Crystals......Page 353
7.2.2.3 Circuit Mapping of Interfacial Defects......Page 356
7.3 Crystalline Structures and Experimental Details......Page 358
7.4.1 Threading Dislocations......Page 362
7.4.2 Stacking-fault Dislocations......Page 366
7.4.3 Interfacial Dislocations and Dislocation Models of Interfacial Structure......Page 370
7.5 Inversion and Stacking Disorder in Relation to Epitaxial Structure......Page 374
7.6.1 Interactions of Inversion Domain Boundaries with Stacking Faults......Page 381
7.6.2 Double-positioning Twinning......Page 386
7.6.3 Junction Lines between Hexagonal and Cubic Nitride Phases......Page 392
7.7 Conclusions......Page 394
7.9 Appendix: The Frank Coordinate System for Hexagonal and Trigonal Crystallography......Page 395
A.1 Projection from a Higher Dimension......Page 396
A.2 Crystallographic Calculations......Page 397
A.3 Reciprocal Space......Page 398
A.4 Matrix Algebra......Page 399
7.10 References......Page 400
8 Extended Defects in Wurtzite GaN Layers: Atomic Structure, Formation, and Interaction Mechanisms......Page 404
8.1 Introduction......Page 405
8.2.1.1 Sapphire......Page 407
8.2.1.2 Silicon Carbide......Page 408
8.2.3 Epitaxial Relationships......Page 410
8.2.4 Bicrystallographic Analysis of Interfacial Defects......Page 411
8.2.5 Growth on SiC......Page 414
8.2.5.2 Defects at Interface Steps......Page 415
8.2.6.1 Geometrical Modeling of the First Monolayers Growth......Page 418
8.2.6.2 Planar Defects......Page 423
8.2.6.4 Steps......Page 424
8.3.2 Threading Dislocations......Page 426
8.3.4 Grain Boundaries......Page 428
8.3.4.1 The Σ=19 Boundary......Page 429
A. The Σ=7 Symmetric Boundary......Page 431
8.3.4.3 The Σ=31 Symmetric Boundary......Page 434
8.3.5 Formation......Page 436
8.4.1 Basal Stacking Faults......Page 437
8.4.2.1 Morphology of the {1120} Stacking Faults Inside the Epitaxial Layers......Page 440
8.4.2.2 Identification of the Stacking Fault Atomic Structure......Page 441
A. On (0001) 6H-SiC Surface......Page 444
B. On (0001) Sapphire......Page 445
8.4.2.4 Relative Stability of the Atomic Configurations......Page 446
8.5 Inversion Domain Boundaries......Page 447
8.5.1 Identification of the Inversion Domains......Page 448
8.5.2 Atomic Models of the Boundary......Page 450
8.5.3 Atomic Structures of the Boundary......Page 451
8.5.4 Atomic Structure of Boundary Plane and Epitaxial Layer Morphology......Page 454
8.5.5 Interaction with Basal Stacking Faults......Page 455
8.5.6 Formation......Page 457
8.6 Discussion and Conclusions......Page 458
8.8 References......Page 461
9.1 Introduction......Page 464
9.2 Suitable Images for Quantitative Analysis......Page 467
9.3 Digitization......Page 469
9.4 Noise......Page 471
9.5.2 Assumptions......Page 476
9.5.3.1 Overview......Page 477
B. Noise Reduction......Page 478
C. Detection of the Lattice Sites......Page 480
E. Lattice Distortion in Discrete and Quasicontinuum Form......Page 481
9.5.4 The Geometric-Phase Method......Page 487
9.5.5 Peak Finding Versus Geometric Phase......Page 491
9.6 Foil-Thickness Effect......Page 492
9.7 From Strain to Stress......Page 497
9.8 Local Chemical Composition......Page 500
9.9 Atomic-Structure Retrieval......Page 503
9.9.1 Artefact-free Sample and Signal-to-Noise Ratio......Page 504
9.9.3 Preprocessing of Image Data and Image Simulations......Page 505
9.9.5 Determination of the Imaging Parameters......Page 506
9.9.7 Precision of the Structure Retrieval......Page 507
9.10 Discussion and Conclusions......Page 508
9.11 Acknowledgments......Page 509
9.12 References......Page 510
Part 3 Processing and Devices......Page 514
10 Ohmic Contacts to GaN......Page 516
10.1 Introduction......Page 517
10.2 Principles of Metal-Semiconductor Contacts......Page 518
10.3 Measurement Techniques......Page 521
10.4 Experimental Studies of Ohmic Contacts to n-Type GaN......Page 522
10.5 Experimental Studies of Ohmic Contacts to p-Type GaN......Page 532
10.7 Directions for Future Research......Page 547
10.8 Acknowledgments......Page 548
10.9 References......Page 549
11.1 Introduction......Page 554
11.2 Historical Overview......Page 555
11.3 White LEDs......Page 559
11.4 UV LEDs......Page 561
11.5 Violet LDs......Page 566
11.6 Summary......Page 567
11.8 References......Page 569
12 GaN-Based Modulation-Doped FETs and Heterojunction Bipolar Transistors......Page 572
12.1 Introduction......Page 573
12.2 Electron Transport Properties in GaN and GaN/AIGaN Heterostructures......Page 575
12.2.1 Bulk Mobility in GaN......Page 577
12.2.2 Polarization Effects, Mobility and Electron Concentration in 2 DEG Systems......Page 581
12.2.3 Partial Strain Relaxation......Page 592
12.2.4 Low-field Transport in 2 DEG Systems......Page 595
12.2.5 High-Field Transport......Page 599
12.3 Modulation-Doped Field Effect Transistors (MODFETs)......Page 601
12.3.1 MODFET Model......Page 602
12.3.1.1 Drain Current Model in MODFETs......Page 608
12.3.1.2 I–V Characteristics......Page 610
12.3.2 Experimental Considerations......Page 611
12.3.3 Schottky Barriers for Gates......Page 614
12.3.4 Contacts to GaN......Page 617
12.3.5 Experimental Performance of GaN MODFETs......Page 619
12.3.6 Power Amplifiers......Page 626
12.3.7 Anomalies in GaN/AlGaN MODFETs......Page 628
12.3.8.1 Low-Frequency Noise......Page 633
12.3.8.2 High-Frequency Noise......Page 636
12.4 Heterojunction Bipolar Transistors......Page 639
12.5 Conclusions......Page 642
12.6 Acknowledgments......Page 643
12.7 References......Page 644
13.1 Introduction......Page 652
13.2 UV to Visible Contrast......Page 656
13.3.1 Silicon-Based UV Photodiodes......Page 657
13.3.2 SiC-Based UV Photodetectors......Page 659
13.4.1.1 Spectral Response......Page 660
13.4.1.2 Time Response......Page 664
13.4.1.3 Effect of a Frequency Modulation of the Incident Optical Signal......Page 665
13.4.2.1 Electrical Properties......Page 666
13.4.2.2 Responsivity......Page 667
13.4.2.3 Time Response......Page 668
13.4.2.4 Noise and Detectivity......Page 669
13.4.2.6 Application of AlGaN Photodetectors to the Simulation of the Biological Effects of UV Light......Page 670
13.4.3 Metal-Semiconductor-Metal (MSM) Photodiodes......Page 671
13.4.3.1 Electrical Properties......Page 672
13.4.3.2 Spectral Response......Page 673
13.4.3.3 Time Response......Page 674
13.4.4 p-n and p-i-n Photodiodes......Page 675
13.4.4.1 Spectral Response......Page 676
13.4.4.2 Time Response......Page 677
13.4.4.4 p-i-n Photodiodes on ELOG GaN......Page 678
13.4.4.5 GaN-Based Avalanche Photodiodes......Page 679
13.4.5.1 Bipolar Phototransitors......Page 680
13.5 Conclusions......Page 681
13.7 References......Page 682
Subject Index......Page 686