Wide Bandgap Semiconductors for Power Electronics

Peter Wellmann, PhD is Professor at the University of Erlangen-Nuremberg, Department of Materials for Electronics and Energy Technology, Germany.Noboru Ohtani, PhD, is Professor at the School of Engineering and Director of the R&D Center for SiC Materials and Processes at Kwansei Gakuin University, Hyogo, Japan.Roland Rupp, PhD, was Senior Principal SiC Technology at Infineon AG in Munich, Germany, where he has built up and coordinated the development of SiC technology for power applications.

• Volume 1Preface xiiiPart I Silicon Carbide (SiC) 11 Dislocation Formation During Physical Vapor Transport Growth of 4H-SiC Crystals 3Noboru Ohtani1.1 Introduction 31.2 Formation of Basal Plane Dislocations During PVT Growth of 4H-SiC Crystals 51.2.1 Plan-View X-ray Topography Observations of Growth Front 51.2.2 Cross-Sectional X-ray Topography Observations of Growth Front 91.2.3 Characteristic BPD Distribution in PVT-Grown 4H-SiC Crystals 131.2.4 BPD Multiplication During PVT Growth 151.3 Dislocation Formation During Initial Stage of PVT Growth of 4H-SiC Crystals 181.3.1 Preparation of 4H-SiCWafers with Beveled Interface Between Grown Crystal and Seed Crystal 181.3.2 Determination of Grown-Crystal/Seed Interface by Raman Microscopy 191.3.3 X-ray Topography Observations of Dislocation Structure at Grown-Crystal/Seed Interface 221.3.4 Formation Mechanism of BPD Networks and Their Migration into Seed Crystal 231.4 Conclusions 28References 302 Industrial Perspectives of SiC Bulk Growth 33Adrian R. Powell2.1 Introduction 332.2 SiC Substrates for GaN LEDs 332.3 SiC Substrates for Power SiC Devices 342.4 SiC Substrates for High-Frequency Devices 352.5 Cost Considerations for Commercial Production of SiC 352.6 Raw Materials 362.7 Reactor Hot Zone 372.8 System Equipment 392.9 Yield 392.10 Turning Boules intoWafers 412.11 Crystal Grind 412.12 Wafer Slicing 422.13 Wafer Polish 442.14 Summary 44Acknowledgments 45References 453 Homoepitaxial Growth of 4H-SiC on Vicinal Substrates 47Birgit Kallinger3.1 Introduction 473.2 Fundamentals of 4H-SiC Homoepitaxy for Power Electronic Devices 473.2.1 4H-SiC Polytype Replication for Homoepitaxial Growth on Vicinal Substrates 483.2.2 Homoepitaxial Growth by Chemical Vapor Deposition (CVD) Process 523.2.3 Doping in Homoepitaxial Growth 533.3 Extended Defects in Homoepitaxial Layers 553.3.1 Classification of Extended Defects According to Glide Systems in 4H-SiC 563.3.2 Dislocation Reactions During Epitaxial Growth 573.3.3 Characterization Methods for Extended Defects in 4H-SiC Epilayers 593.4 Point Defects and Carrier Lifetime in Epilayers 623.4.1 Classification and General Properties of Point Defects in 4H-SiC 623.4.2 Basics on Recombination Carrier Lifetime in 4H-SiC 643.4.3 Carrier Lifetime-Affecting Point Defects 653.4.4 Carrier Lifetime Measurement in Epiwafers and Devices 683.5 Conclusion 69Acknowledgments 70References 704 Industrial Perspective of SiC Epitaxy 75Albert A. Burk, Jr., Michael J. O’Loughlin, Denis Tsvetkov, and Scott Ustin4.1 Introduction 754.2 Background 764.3 The Basics of SiC Epitaxy 764.4 SiC Epi Historical Origins 784.5 Planetary Multi-wafer Epitaxial Reactor Design Considerations 804.5.1 Rapidly Rotating Reactors 814.5.2 Horizontal Hot-Wall Reactors 824.6 Latest High-Throughput Epitaxial Reactor Status 824.7 Benefits and Challenges for Increasing Growth Rate in all Reactors 864.8 IncreasingWafer Diameters, Device Processing Considerations, and Projections 864.9 Summary 89Acknowledgment 90References 905 Status of 3C-SiC Growth and Device Technology 93Peter Wellmann, Michael Schöler, Philipp Schuh, Mike Jennings, Fan Li, Roberta Nipoti, Andrea Severino, Ruggero Anzalone, Fabrizio Roccaforte, Massimo Zimbone, and Francesco La Via5.1 Introduction, Motivation, Short Review on 3C-SiC 935.2 Nucleation and Epitaxial Growth of 3C-SC on Si 955.2.1 Growth Process 955.2.2 Defects 985.2.3 Stress 1025.3 Bulk Growth of 3C-SiC 1035.3.1 Sublimation Growth of (111)-oriented 3C-SiC on Hexagonal SiC Substrates 1045.3.2 Sublimation Growth of 3C-SiC on 3C-SiC CVD Seeding Layers 1055.3.3 Continuous Fast CVD Growth of 3C-SiC on 3C-SiC CVD Seeding Layers 1105.4 Processing and Testing of 3C-SiC Based Power Electronic Devices 1175.4.1 Prospects for 3C-SiC Power Electronic Devices 1175.4.2 3C-SiC Device Processing 1175.4.3 MOS Processing 1185.4.4 3C-SiC/SiO2 Interface Passivation 1205.4.5 Surface Morphology Effects on 3C-SiC Thermal Oxidation 1215.4.6 Thermal Oxidation Temperature Effects for 3C-SiC 1225.4.7 Ohmic Contact Metalization 1235.4.8 N-type 3C-SiC Ohmic Contacts 1265.4.9 Ion Implantation 1265.5 Summary 127Acknowledgements 127References 1276 Intrinsic and Extrinsic Electrically Active Point Defects in SiC 137Ulrike Grossner, Joachim K. Grillenberger, Judith Woerle, Marianne E. Bathen, and Johanna Müting6.1 Characterization of Electrically Active Defects 1416.1.1 Deep Level Transient Spectroscopy 1416.1.1.1 Profile Measurements 1436.1.1.2 Poole–Frenkel Effect 1436.1.1.3 Laplace DLTS 1436.1.2 Low-energy Muon Spin Rotation Spectroscopy 1446.1.2.1 μSR and Semiconductors 1446.1.3 Density Functional Theory 1456.2 Intrinsic Electrically Active Defects in SiC 1466.2.1 The Carbon Vacancy, VC 1476.2.2 The Silicon Vacancy, VSi 1526.3 Transition Metal and Other Impurity Levels in SiC 1536.4 Summary 159References 1637 Dislocations in 4H-SiC Substrates and Epilayers 169Balaji Raghothamachar and Michael Dudley7.1 Introduction 1697.2 Dislocations in Bulk 4H-SiC 1707.2.1 Micropipes (MPs) and Closed-core Threading Screw Dislocations (TSDs) 1707.2.2 Basal Plane Dislocations (BPDs) 1717.2.3 Threading Edge Dislocations (TEDs) 1717.2.4 Interaction between BPDs and TEDs 1717.2.4.1 Hopping Frank–Read Source of BPDs 1717.2.5 Threading Mixed Dislocations (TMDs) in 4H-SiC 1737.2.5.1 Reaction Between Threading Dislocations with Burgers Vectors of −c+a and c+a Wherein the Opposite c-Components Annihilate Leaving Behind the Two a-Components 1747.2.5.2 Reaction Between Threading Dislocations with Burgers Vectors of –c and c+a Leaving Behind the a-Component 1757.2.5.3 Reaction Between Opposite-sign Threading Screw Dislocations with Burgers Vectors c and −c 1757.2.5.4 Nucleation of Opposite Pair of c+a Dislocations and Their Deflection 1757.2.5.5 Deflection of Threading c+a, c and Creation of Stacking Faults 1777.2.6 Prismatic Slip during PVT growth 4H-SiC Boules 1807.2.7 Relationship Between Local Basal Plane Bending and Basal Plane Dislocations in PVT-grown 4H-SiC SubstrateWafers 1817.2.8 Investigation of Dislocation Behavior at the Early Stage of PVT-grown 4H-SiC Crystals 1817.3 Dislocations in Homoepitaxial 4H-SiC 1847.3.1 Conversion of BPDs into TEDs 1847.3.2 Susceptibility of Basal Plane Dislocations to the Recombination-Enhanced Dislocation Glide in 4H Silicon Carbide 1847.3.3 Nucleation of TEDs, BPDs, and TSDs at Substrate Surface Damage 1887.3.4 Nucleation Mechanism of Dislocation Half-Loop Arrays in 4H-SiC Homo-Epitaxial Layers 1917.3.5 V- and Y-shaped Frank-type Stacking Faults 1927.4 Summary 192Acknowledgments 195References 1958 Novel Theoretical Approaches for Understanding and Predicting Dislocation Evolution and Propagation 199Binh Duong Nguyen and Stefan Sandfeld8.1 Introduction 1998.2 General Modeling and Simulation Approaches 2008.3 Continuum Dislocation Modeling Approaches 2018.3.1 Alexander–Haasen Model 2018.3.2 Continuum Dislocation Dynamics Models 2028.3.2.1 The Simplest Model: Straight Parallel Dislocation with the Same Line Direction 2038.3.2.2 The “Groma” Model: Straight Parallel Dislocations with Two Line Directions 2038.3.2.3 The Kröner–Nye Model for Geometrically Necessary Dislocations 2048.3.2.4 Three-dimensional Continuum Dislocation Dynamics (CDD) 2048.4 Example 1: Comparison of the Alexander–Haasen and the Groma Model 2068.4.1 Governing Equations 2068.4.2 Physical System and Model Setup 2068.4.3 Results and Discussion 2098.5 Example 2: Dislocation Flow Between Veins 2118.5.1 A Brief Introduction to Dislocation Patterning and the Similitude Principle 2118.5.2 Physical System and Model Setup 2138.5.3 Geometry and Initial Values 2148.5.4 Results and Discussion 2158.6 Summary and Conclusion 219References 2209 Gate Dielectrics for 4H-SiC Power Switches: Understanding the Structure and Effects of Electrically Active Point Defects at the 4H-SiC/SiO2 Interface 225Gregor Pobegen and Thomas Aichinger9.1 Introduction 2259.2 Electrical Impact of Traps on MOSFET Characteristics 2259.2.1 Sub threshold Sweep Hysteresis 2269.2.2 Preconditioning Measurement 2319.2.3 Bias Temperature Instability 2339.2.4 Reduced Channel Electron Mobility 2359.3 Microscopic Nature of Electrically Active Traps Near the Interface 2379.3.1 The PbC Defect and the Subthreshold Sweep Hysteresis 2379.3.2 The Intrinsic Electron Trap and the Reduced MOSFET Mobility 2389.3.3 Point Defect Candidates for BTI 2409.4 Conclusions and Outlook 242References 24310 Epitaxial Graphene on Silicon Carbide as a Tailorable Metal–Semiconductor Interface 249Michael Krieger and Heiko B. Weber10.1 Introduction 24910.2 Epitaxial Graphene as a Metal 24910.3 Fabrication and Structuring of Epitaxial Graphene 25010.3.1 Epitaxial Growth by Thermal Decomposition 25010.3.2 Intercalation 25110.3.3 Structuring of Epitaxial Graphene Layers and Partial Intercalation 25210.4 Epitaxial Graphene as Tailorable Metal/Semiconductor Contact 25310.4.1 Ohmic Contacts 25410.4.2 Schottky Contacts 25610.5 Monolithic Epitaxial Graphene Electronic Devices and Circuits 25710.5.1 Discrete Epitaxial Graphene Devices 25710.5.2 Monolithic Integrated Circuits 25910.6 Novel Experiments on Light–Matter Interaction Enabled by Epitaxial Graphene 26010.6.1 High-Frequency Operation and Ultimate Speed Limits of Schottky Diodes 26010.6.2 Transparent Electrical Access to SiC for Novel Quantum Technology Applications 26310.7 Conclusion 264Acknowledgments 265References 26511 Device Processing Chain and Processing SiC in a Foundry Environment 271Arash Salemi, Minseok Kang, Woongje Sung, and Anant K. Agarwal11.1 Introduction 27111.2 DMOSFET Structure 27111.3 Process Integration of SiC MOSFETs 27311.3.1 Lithography 28311.3.2 SiC Etching 28311.3.3 Ion Implantation and Activation Annealing 29011.3.4 Oxidation and Oxide 29311.3.5 Post Oxidation Annealing 29611.3.6 Poly-Si Deposition 29811.3.7 Backside Thinning andWaffle Substrates 30011.3.8 Ohmic Contacts and Metallization 30111.3.9 Polyimide Deposition 30211.4 Commercial Foundries for Si and SiC Devices 30311.4.1 Cost Model 30311.4.1.1 Cost Roadmap for WBG Devices 30311.4.2 New Equipment and Processing Requirements 30511.5 Dedicated Foundries vs. Commercial Foundries 306References 30712 Unipolar Device in SiC: Diodes and MOSFETs 319Sei-Hyung Ryu12.1 Introduction 31912.2 Unipolar Diodes – 4H-SiC JBS Diodes 32012.2.1 Optimization of 4H-SiC JBS Diodes 32312.2.1.1 Injection from the p+ Regions for Surge Operation 32412.2.1.2 Trench JBS Diodes 32612.2.1.3 Use of LowWork Function Metal for Anode Metal 32712.3 Unipolar Switches: Power MOSFETs 32912.3.1 4H-SiC Power MOSFET Structures 33212.3.1.1 DMOSFETs 33212.3.1.2 Trench MOSFETs 33712.3.2 Advanced Power MOSFET Structures in 4H-SiC 34212.3.2.1 Superjunction MOSFETs in 4H-SiC 34212.3.2.2 Integrated JBS Diodes in 4H-SiC Power MOSFETs 34512.4 Summary 346References 348Volume 213 Ultra-High-Voltage SiC Power Device 353Yoshiyuki Yonezawa and Koji Nakayama14 SiC Reliability Aspects 387Josef Lutz and Thomas Basler15 Industrial Systems Using SiC Power Devices 433Nando Kaminski16 Special Focus on HEV and EV Applications: Activities of Automotive Industries Applying SiC Devices for Automotive Applications 467Kimimori Hamada, Keiji Toda, Hiromichi Nakamura, Shigeharu Yamagami, and Kazuhiro Tsuruta17 Point Defects in Silicon Carbide for Quantum Technology 503András Csóré and Adam GaliPart II Gallium Nitride (GaN), Diamond, and Ga2O3 52918 Ammonothermal and HVPE Bulk Growth of GaN 531Robert Kucharski, Tomasz Sochacki, Boleslaw Lucznik, Mikolaj Amilusik, Karolina Grabianska, Malgorzata Iwinska, and Michal Bockowski19 GaN on Si: Epitaxy and Devices 555Hidekazu Umeda20 Growth of Single Crystal Diamond Wafers for Future Device Applications 583Matthias Schreck21 Diamond Wafer Technology, Epitaxial Growth, and Device Processing 633Hideaki Yamada, Hiromitsu Kato, Shinya Ohmagari, and Hitoshi Umezawa22 Gallium Oxide: Material Properties and Devices 659Masataka HigashiwakiIndex 681