Systematically discusses the growth method, material properties, and applications for key semiconductor materials
MOVPE is a chemical vapor deposition technique that produces single or polycrystalline thin films. As one of the key epitaxial growth technologies, it produces layers that form the basis of many optoelectronic components including mobile phone components (GaAs), semiconductor lasers and LEDs (III-Vs, nitrides), optical communications (oxides), infrared detectors, photovoltaics (II-IV materials), etc. Featuring contributions by an international group of academics and industrialists, this book looks at the fundamentals of MOVPE and the key areas of equipment/safety, precursor chemicals, and growth monitoring. It covers the most important materials from III-V and II-VI compounds to quantum dots and nanowires, including sulfides and selenides and oxides/ceramics.
Sections in every chapter of Metalorganic Vapor Phase Epitaxy (MOVPE): Growth, Materials Properties and Applications cover the growth of the particular materials system, the properties of the resultant material, and its applications. The book offers information on arsenides, phosphides, and antimonides; nitrides; lattice-mismatched growth; CdTe, MCT (mercury cadmium telluride); ZnO and related materials; equipment and safety; and more. It also offers a chapter that looks at the future of the technique.
- Covers, in order, the growth method, material properties, and applications for each material
- Includes chapters on the fundamentals of MOVPE and the key areas of equipment/safety, precursor chemicals, and growth monitoring
- Looks at important materials such as III-V and II-VI compounds, quantum dots, and nanowires
- Provides topical and wide-ranging coverage from well-known authors in the field
- Part of the Materials for Electronic and Optoelectronic Applications series
Metalorganic Vapor Phase Epitaxy (MOVPE): Growth, Materials Properties and Applications is an excellent book for graduate students, researchers in academia and industry, as well as specialist courses at undergraduate/postgraduate level in the area of epitaxial growth (MOVPE/ MOCVD/ MBE).
Table of Contents
List of Contributors xv
Foreword xvii
Series Preface xix
Preface xxi
Safety and Environment Disclaimer xxiii
1 Introduction to Metalorganic Vapor Phase Epitaxy 1
S.J.C. Irvine and P. Capper
1.1 Historical Background of MOVPE 1
1.2 Basic Reaction Mechanisms 4
1.3 Precursors 8
1.4 Types of Reactor Cell 9
1.5 Introduction to Applications of MOVPE 11
1.5.1 AlN for UV Emitters 11
1.5.2 GaAs/AlGaAs VCSELS 11
1.5.3 Multijunction Solar Cells 12
1.5.4 GaAs and InP Transistors for High‐Frequency Devices 13
1.5.5 Infrared Detectors 14
1.5.6 Photovoltaic and Thermophotovoltaic Devices 14
1.6 Health and Safety Considerations in MOVPE 15
1.7 Conclusions 16
References 16
2 Fundamental Aspects of MOVPE 19
G.B. Stringfellow
2.1 Introduction 19
2.2 Thermodynamics 20
2.2.1 Thermodynamics of MOVPE Growth 20
2.2.2 Solid Composition 24
2.2.3 Phase Separation 29
2.2.4 Ordering 31
2.3 Kinetics 35
2.3.1 Mass Transport 35
2.3.2 Precursor Pyrolysis 36
2.3.3 Control of Solid Composition 37
2.4 Surface Processes 40
2.4.1 Surface Reconstruction 41
2.4.2 Atomic‐Level Surface Processes 42
2.4.3 Effects of Surface Processes on Materials Properties 44
2.4.4 Surfactants 46
2.5 Specific Systems 52
2.5.1 AlGaInP 52
2.5.2 Group III Nitrides 53
2.5.3 Novel Alloys 56
2.6 Summary 59
References 60
3 Column III: Phosphides, Arsenides, and Antimonides 71
H. Hardtdegen and M. Mikulics
3.1 Introduction 71
3.2 Precursors for Column III Phosphides, Arsenides, and Antimonides 73
3.3 GaAs‐Based Materials 74
3.3.1 (AlGa)As/GaAs Properties and Deposition 74
3.3.2 GaInP, (AlGa)InP/GaAs Properties and Deposition 79
3.4 InP‐Based Materials 82
3.4.1 InP Properties and Deposition 82
3.4.2 AlInAs/GaInAs/AlGaInAs Properties and Deposition 83
3.4.3 AlInAs/GaInAs/InP Heterostructures 84
3.4.4 InxGa1-xAsyP1-y Properties and Deposition 84
3.5 Column III Antimonides Properties and Deposition 86
3.5.1 Deposition of InSb, GaSb, and AlSb 87
3.5.2 Deposition of Ternary Column III Alloys (AlGa)Sb and (GaIn)Sb 89
3.5.3 Deposition of Ternary Column V Alloys In(AsSb), GaAsSb 89
3.5.4 Deposition of Quaternary Alloys 90
3.5.5 Epitaxy of Electronic Device Structures 90
3.5.6 Epitaxy of Optoelectronic Device Structures 95
3.6 In Situ Optical Characterization/Growth Control 100
3.7 Conclusions 100
References 101
4 Nitride Semiconductors 109
A. Dadgar and M. Weyers
4.1 Introduction 109
4.2 Properties of III‐Nitrides 110
4.3 Challenges in the Growth of III‐Nitrides 111
4.3.1 Lattice and Thermal Mismatch 111
4.3.2 Ternary Alloys: Miscibility and Compositional Homogeneity 113
4.3.3 Gas‐Phase Prereactions 115
4.3.4 Doping of III‐Nitrides 117
4.4 Substrates 120
4.4.1 Heteroepitaxy on Foreign Substrates 122
4.4.2 GaN Growth on Sapphire 125
4.4.3 III‐N Growth on SiC 126
4.4.4 GaN Growth on Silicon 127
4.5 MOVPE Growth Technology 130
4.5.1 Precursors 130
4.5.2 Reactors and In Situ Monitoring 130
4.6 Economic Importance 136
4.6.1 Optoelectronic Devices 137
4.6.2 Electronic Devices 138
4.7 Conclusions 138
References 138
5 Metamorphic Growth and Multijunction III‐V Solar Cells 149
N.H. Karam, C.M. Fetzer, X.‐Q. Liu, M.A. Steiner, and K.L. Schulte
5.1 Introduction to MOVPE for Multijunction Solar Cells 149
5.1.1 III‐V PV Solar Cell Opportunities and Applications 149
5.1.2 Metamorphic Multijunction Solar Cells 151
5.1.3 Reactor Technology for Metamorphic Epitaxy 154
5.2 Upright Metamorphic Multijunction (UMM) Solar Cells 154
5.2.1 Introduction and History of Upright Metamorphic Multijunctions 154
5.2.2 MOVPE Growth Considerations of UMM 156
5.2.3 Growth and Device Results 158
5.2.4 Challenges and Future Outlook 162
5.3 Inverted Metamorphic Multijunction (IMM) Solar Cells 162
5.3.1 Introduction and History of Inverted Metamorphic Multijunctions 162
5.3.2 MOVPE Growth Considerations of IMM 164
5.3.3 Growth and Device Results 167
5.3.4 Challenges and Future Outlook 169
5.4 Conclusions 169
References 170
6 Quantum Dots 175
E. Hulicius, A. Hospodková, and M. Zíková
6.1 General Introduction to the Topic 175
6.1.1 Definition and History 175
6.1.2 Paradigm of Quantum Dots 176
6.1.3 QD Types 176
6.2 AIIIBV Materials and Structures 178
6.2.1 QDs Embedded in the Structure 178
6.2.2 Semiconductor Materials for Embedded QDs 180
6.3 Growth Procedures 181
6.3.1 Comparison of MBE‐ and MOVPE‐Grown QDs 181
6.3.2 Growth Parameters 182
6.3.3 QD Surrounding Layers 185
6.4 In Situ Measurements 193
6.4.1 Reflectance Anisotropy Spectroscopy of QD Growth 193
6.4.2 Other Supporting In Situ Measurements 197
6.5 Structure Characterization 198
6.5.1 Optical: Photo‐, Magnetophoto‐, Electro‐luminescence, and Spin Detection 198
6.5.2 Microscopies - AFM, TEM, XSTM, BEEM/BEES 200
6.5.3 Electrical: Photocurrent, Capacitance Measurements 202
6.6 Applications 203
6.6.1 QD Lasers, Optical Amplifiers, and LEDs 204
6.6.2 QD Detectors, FETs, Photovoltaics, and Memories 205
6.7 Summary 208
6.8 Future Perspectives 208
Acknowledgment 209
References 209
7 III‐V Nanowires and Related Nanostructures: From Nitrides to Antimonides 217
H.J. Joyce
7.1 Introduction to Nanowires and Related Nanostructures 217
7.2 Geometric and Crystallographic Properties of III‐V Nanowires 219
7.2.1 Crystal Phase 219
7.2.2 Growth Direction, Morphology, and Side‐Facets 220
7.3 Particle‐Assisted MOVPE of Nanowires 222
7.3.1 The Phase of the Particle 222
7.3.2 The Role of the Particle 224
7.3.3 Axial and Radial Growth Modes 226
7.3.4 Self‐Assisted Growth 228
7.4 Selective‐Area MOVPE of Nanowires and Nanostructures 228
7.4.1 The Role of the Mask 229
7.4.2 Axial and Radial Growth Modes 230
7.5 Alternative Techniques for MOVPE of Nanowires 231
7.6 Novel Applications of Nanowires 231
7.7 Concluding Remarks 233
References 234
8 Monolithic III/V integration on (001) Si substrate 241
B. Kunert and K. Volz
8.1 Introduction 241
8.2 III/V‐Si Interface 243
8.2.1 Si Surfaces 243
8.2.2 Interface Formation in the Presence of Impurities and MO Precursors 247
8.2.3 Atomic III/V on Si Interface Structure 249
8.2.4 Antiphase Domains 251
8.2.5 III/V Growth on Si(001) 252
8.3 Heteroepitaxy of Bulk Layers on Si 255
8.3.1 Lattice‐Matched Growth on Si 257
8.3.2 Metamorphic Growth on Blanket Si 258
8.3.3 Selective‐Area Growth (SAG) on Si 264
8.4 Conclusions 282
References 282
9 MOVPE Growth of Cadmium Mercury Telluride and Applications 293
C.D. Maxey, P. Capper, and I.M. Baker
9.1 Requirement for Epitaxy 293
9.2 History 294
9.3 Substrate Choices 295
9.3.1 Orientation 296
9.3.2 Substrate Material 296
9.4 Reactor Design 297
9.4.1 Process Abatement Systems 298
9.5 Process Parameters 299
9.6 Metalorganic Sources 299
9.7 Uniformity 300
9.8 Reproducibility 302
9.9 Doping 302
9.10 Defects 304
9.11 Annealing 307
9.12 In Situ Monitoring 308
9.13 Background for Applications of MOVPE MCT 308
9.13.1 Introduction to Infrared Imaging and Atmospheric Windows 308
9.13.2 MCT Infrared Detector Market in the Modern Era 309
9.14 Manufacturing Technology for MOVPE Photodiode Arrays 311
9.14.1 Mesa Heterojunction Devices (MHJ) 311
9.14.2 Wafer‐Scale Processing 312
9.15 Advanced MCT Technologies 312
9.15.1 Small‐Pixel Technology 313
9.15.2 Higher Operating Temperature (HOT) Device Structures 313
9.15.3 Two‐Color Array Technology 314
9.15.4 Nonequilibrium Device Structures 316
9.16 MOVPE MCT for Scientific Applications 316
9.16.1 Linear‐Mode Avalanche Photodiode Arrays (LmAPDs) in MOVPE 316
9.17 Conclusions and Future Trends for MOVPE MCT Arrays 320
Definitions 321
References 322
10 Cadmium Telluride and Related II‐VI Materials 325
G. Kartopu and S.J.C. Irvine
10.1 Introduction and Historical Background 325
10.2 CdTe Homoepitaxy 327
10.3 CdTe Heteroepitaxy 327
10.3.1 InSb 327
10.3.2 Sapphire 328
10.3.3 GaAs 329
10.3.4 Silicon 330
10.4 Low‐Temperature Growth and Alternative Precursors 330
10.5 Photoassisted MOVPE 332
10.6 Plasma‐Assisted MOVPE 333
10.7 Polycrystalline MOCVD 333
10.8 In Situ Monitoring of CdTe 334
10.8.1 Mechanisms for Laser Reflectance (LR) Monitoring 335
10.9 MOCVD of CdTe for Planar Solar Cells 337
10.9.1 CdS and CdZnS Window Layers 338
10.9.2 CdTe Absorber Layer 338
10.9.3 CdCl2 Treatment Layer 342
10.9.4 Photovoltaic Planar Devices 343
10.10 Core‐Shell Nanowire Photovoltaic Devices 345
10.11 Inline MOCVD for Scaling of CdTe 347
10.12 MOCVD of CdTe for Radiation Detectors 350
References 351
11 ZnO and Related Materials 355
V. Muñoz‐Sanjosé and S.J.C. Irvine
11.1 Introduction 355
11.2 Sources for the MOCVD Growth of ZnO and Related Materials 356
11.2.1 Metalorganic Zinc Precursors 356
11.2.2 Metalorganic Cadmium Precursors 360
11.2.3 Metalorganic Magnesium Precursors 360
11.2.4 Precursors for Oxygen 361
11.2.5 Precursors for Doping 363
11.3 Substrates for the MOCVD Growth of ZnO and Related Materials 364
11.3.1 ZnO Single Crystals and ZnO Templates as Substrates 365
11.3.2 Sapphire (Al2O3) 367
11.3.3 Silicon 369
11.3.4 Glass Substrates 372
11.4 Some Techniques for the MOCVD Growth of ZnO and Related Materials 373
11.4.1 Atmospheric and Low‐Pressure Conditions in Conventional MOCVD Systems 374
11.4.2 MOCVD‐Assisted Processes 376
11.5 Crystal Growth of ZnO and Related Materials 380
11.5.1 Crystal Growth by MOCVD of ZnO Layers 380
11.5.2 Crystal Growth of ZnO Nanostructures 393
11.5.3 Crystal Growth of ZnO‐Related Materials 398
11.5.4 Doping of ZnO and Related Materials 400
11.6 Conclusions 405
Acknowledgments 406
References 406
12 Epitaxial Systems for III‐V and III‐Nitride MOVPE 423
W. Lundin and R. Talalaev
12.1 Introduction 423
12.2 Typical Engineering Solutions Inside MOVPE Tools 424
12.2.1 Gas‐Blending System 424
12.2.2 Exhaust System 433
12.2.3 Reactors 435
12.3 Reactors for MOVPE of III‐V Materials 438
12.3.1 General Features of III‐V MOVPE 438
12.3.2 From Simple Horizontal Flow to Planetary Reactors 439
12.3.3 Close‐Coupled Showerhead (CCS) Reactors 445
12.3.4 Rotating‐Disk Reactors 447
12.4 Reactors for MOVPE of III‐N Materials 451
12.4.1 Principal Differences between MOVPE of Classical III‐Vs and III‐Ns 451
12.4.2 Rotating‐Disk Reactors 454
12.4.3 Planetary Reactors 455
12.4.4 CCS Reactors 458
12.4.5 Horizontal Flow Reactors for III‐N MOVPE 459
12.5 Twenty‐Five Years of Commercially Available III‐N MOVPE Reactor Evolution 462
References 464
13 Ultrapure Metal‐Organic Precursors for MOVPE 467
D.V. Shenai‐Khatkhate
13.1 Introduction 467
13.1.1 MOVPE Precursor Classes and Impurities 468
13.2 Stringent Requirements for Suitable MOVPE Precursors 472
13.3 Synthesis and Purification Strategies for Ultrapure MOVPE Precursors 472
13.3.1 Synthetic Strategies for Ultrapure MOVPE Precursors 472
13.3.2 Purification Strategies for MOVPE Precursors 476
13.4 MOVPE Precursors for III‐V Compound Semiconductors 483
13.4.1 Group III MOVPE Precursors 483
13.4.2 Group V MOVPE Precursors 488
13.5 MOVPE Precursors for II‐VI Compound Semiconductors 493
13.5.1 Group II MOVPE Precursors 493
13.5.2 Group VI MOVPE Precursors 496
13.6 MOVPE Dopants for Compound Semiconductors 499
13.7 Environment, Health, and Safety (EHS) Aspects of MOVPE Precursors 500
13.7.1 General Aspects and Considerations 500
13.7.2 Employee and Environment Exposure Aspects 501
13.7.3 Employee and Workplace Exposure Limits 502
13.8 Conclusions and Future Trends 502
Acknowledgments 503
References 503
14 Future Aspects of MOCVD Technology for Epitaxial Growth of Semiconductors 507
T. Detchprohm, J.‐H. Ryou, X. Li, and R.D. Dupuis
14.1 Introduction - Looking Back 507
14.2 Future Equipment Development 510
14.2.1 Production MOCVD 510
14.2.2 R&D MOCVD 511
14.2.3 MOCVD for Ultrawide‐Bandgap III‐Nitrides 512
14.2.4 MOCVD for Emerging Materials 513
14.2.5 Democratization of MOCVD 514
14.3 Future Applications for MOCVD Research in Semiconductor Materials 515
14.3.1 Heteroepitaxy 515
14.3.2 Nanostructural Materials 527
14.3.3 Poly, Amorphous, and Other Materials 532
14.4 Past, Present, and Future Commercial Applications 535
14.4.1 LEDs 535
14.4.2 Lasers 536
14.4.3 OEICs 536
14.4.4 High‐Speed Electronics 536
14.4.5 High‐Power Electronics 537
14.4.6 Solar Cells 537
14.4.7 Detectors 538
14.5 Summary and Conclusions 538
Acknowledgments 539
References 539
Index 549
