3 RD EDITION Semiconductor Devices Physics and Technology S. M. SZE EtronTech Distinguished Chair Professor College of Electrical and Computer Engineering National Chiao Tung University Hsinchu, Taiwan M. K. LEE Professor Department of Electrical Engineering National Sun Yat-sen University Kaohsiung, Taiwan JOHN WILEY & SONS, INC. Acquisitions Editor Dan Sayre Marketing Manager Christopher Ruel Senior Editorial Assistant Katie Singleton Editorial Program Assistant Samantha Mendel Production Manager Micheline Frederick Cover Designer Wendy Lai Pre-press Service Robots & Cupcakes This book was typeset in Times Roman by the authors and printed and bound by Quad Graphics/Versailles. The cover was printed by Quad Graphics/Versailles. cover photo: © 2010 IEEE. Reprinted, with permission, from IEDM Technical Digest, S. Whang et. al, "Novel 3-dimensional Dual Control-gate with Surrounding Floating-gate (DC-SF) NAND flash cell for 1Tb file storage application." 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Contents Preface vii CHAPTER 4 Acknowledgments ix Bipolar Transistors and Related Devices 123 CHAPTER 0 1 4.1 Transistor Action 124 Introduction 4.2 Static Characteristics of Bipolar Transistors 129 0.1 Semiconductor Devices 1 4.3 Frequency Response and Switching of 0.2 Semiconductor Technology 6 Bipolar Transistors 137 Summary 12 4.4 Nonideal Effects 142 4.5 Heterojunction Bipolar Transistors 146 PART I 4.6 Thyristors and Related Power Devices 149 SEMICONDUCTOR PHYSICS Summary 155 CHAPTER 1 CHAPTER 5 Energy Bands and Carrier Concentration in MOS Capacitor and MOSFET 160 Thermal Equilibrium 15 5.1 Ideal MOS Capacitor 160 1.1 Semiconductor Materials 15 5.2 SiO-Si MOS Capacitor 169 2 1.2 Basic Crystal Structures 17 5.3 Carrier Transport in MOS Capacitors 174 1.3 Valence Bonds 22 5.4 Charge-Coupled Devices 177 1.4 Energy Bands 23 5.5 MOSFET Fundamentals 180 1.5 Intrinsic Carrier Concentration 29 Summary 192 1.6 Donors and Acceptors 34 Summary 40 CHAPTER 6 Advanced MOSFET and Related Devices 195 CHAPTER 2 6.1 MOSFET Scaling 195 Carrier Transport Phenomena 43 6.2 CMOS and BiCMOS 205 2.1 Carrier Drift 43 6.3 MOSFET on Insulator 210 2.2 Carrier Diffusion 53 6.4 MOS Memory Structures 214 2.3 Generation and Recombination Processes 56 6.5 Power MOSFET 223 2.4 Continuity Equation 62 Summary 224 2.5 Thermionic Emission Process 68 2.6 Tunneling Process 69 CHAPTER 7 2.7 Space-Charge Effect 71 MESFET and Related Devices 228 2.8 High-Field Effects 73 7.1 Metal-Semiconductor Contacts 229 Summary 77 7.2 MESFET 240 7.3 MODFET 249 PART II Summary 255 SEMICONDUCTOR DEVICES CHAPTER 8 CHAPTER 3 Microwave Diodes; Quantum-Effect and p-n Junction 82 Hot-Electron Devices 258 3.1 Thermal Equilibrium Condition 83 8.1 Microwave Frequency Bands 259 3.2 Depletion Region 87 8.2 Tunnel Diode 260 3.3 Depletion Capacitance 95 8.3 IMPATT Diode 260 3.4 Current-Voltage Characteristics 99 8.4 Transferred-Electron Devices 265 3.5 Charge Storage and Transient Behavior 108 8.5 Quantum-Effect Devices 269 3.6 Junction Breakdown 111 8.6 Hot-Electron Devices 274 3.7 Heterojunction 117 Summary 277 Summary 120 v CHAPTER 9 14.4 Range of Implanted Ions 483 Light Emitting Diodes and Lasers 280 14.5 Implant Damage and Annealing 490 9.1 Radiative Transitions and Optical Absorption 280 14.6 Implantation-Related Processes 495 9.2 Light-Emitting Diodes 286 Summary 501 9.3 Various Light-Emitting Diodes 291 CHAPTER 15 9.4 Semiconductor Lasers 302 Integrated Devices 505 Summary 319 15.1 Passive Components 507 CHAPTER 10 15.2 Bipolar Technology 511 Photodetectors and Solar Cells 323 15.3 MOSFET Technology 516 10.1 Photodetectors 323 15.4 MESFET Technology 529 10.2 Solar Cells 336 15.5 Challenges for Nanoelectronics 532 10.3 Silicon and Compound-Semiconductor Solar Cells 343 Summary 537 10.4 Third-Generation Solar Cells 348 APPENDIX A 10.5 Optical Concentration 352 Summary 352 List of Symbols 541 APPENDIX B PART III International Systems of Units (SI Units) 543 SEMICONDUCTOR TECHNOLOGY APPENDIX C CHAPTER 11 Unit Prefixes 544 Crystal Growth and Epitaxy 357 11.1 Silicon Crystal Growth from the Melt 357 APPENDIX D 11.2 Silicon Float-Zone Proces 363 Greek Alphabet 545 11.3 GaAs Crystal-Growth Techniques 367 11.4 Material Characterization 370 APPENDIX E 11.5 Epitaxial-Growth Techniques 377 Physical Constants 546 11.6 Structures and Defects in Epitaxial 384 APPENDIX F Layers Summary 388 Properties of Important Element and Binary Compound Semiconductors at 300 K 547 CHAPTER 12 APPENDIX G Film Formation 392 12.1 Thermal Oxidation 392 Properties of Si and GaAs at 300 K 548 12.2 Chemical Vapor Deposition of Dielectrics 400 APPENDIX H 12.3 Chemical Vapor Deposition of Polysilicon 409 Derivation of the Density of States in a Semiconductor 549 12.4 Atom Layer Deposition 412 12.5 Metallization 414 APPENDIX I Summary 425 Derivation of Recombination Rate for Indirect Recombination 553 CHAPTER 13 Lithography and Etching 428 APPENDIX J 13.1 Optical Lithography 428 Calculation of the Transmission Coefficient for 13.2 Next-Generation Lithographic Methods 441 a Symmetric Resonant-Tunneling Diode 555 13.3 Wet Chemical Etching 447 13.4 Dry Etching 450 APPENDIX K Summary 462 Basic Kinetic Theory of Gases 557 CHAPTER 14 APPENDIX L Impurity Doping 466 Answers to Selected Problems 559 14.1 Basic Diffusion Process 467 14.2 Extrinsic Diffusion 476 Photo credits 563 14.3 Diffusion-Related Processes 480 Index 565 vi Preface The book is an introduction to the physical principles of modern semiconductor devices and their advanced fabrication technology. It is intended as a text for undergraduate students in applied physics, electrical and electronics engineering, and materials science. It can also serve as a reference for graduate students and practicing engineers as well as scientists who are not familiar with the subject or need an update on device and technology developments. WHAT’S NEW IN THE THIRD EDITION (cid:114) 35% of the material has been revised or updated. We have added many sections of current interest such as CMOS image sensors, FinFET, 3rd generation solar cells, and atomic layer deposition. In addition, we have omitted or reduced sections of less important topics to maintain the overall book length. (cid:114) We have expanded the treatment of MOSFET and related devices to two chapters because of their importance in electronic applications. We have also expanded the treatment of photonic devices to two chapters because of their importance in communication and alternative energy sources. (cid:114) To improve the development of each subject, sections that contain graduate-level mathematics or physical concepts have been omitted or moved to the Appendixes,. TOPICAL COVERAGE (cid:114) Chapter 0 gives a brief historical review of major semiconductor devices and key technology developments. The following text is organized in three parts. (cid:114) Part I, Chapters 1–2, describes the basic properties of semiconductors and their conduction processes, with special emphasis on the two most important semiconductors, silicon (Si) and gallium arsenide (GaAs). The concepts in Part I , which will be used throughout the book, require a background knowledge of modern physics and college calculus. (cid:114) Part II, Chapters 3–10, discusses the physics and characteristics of all major semiconductor devices. We begin with the p–n junction, the key building block of most semiconductor devices. We proceed to bipolar and field-effect devices and then cover microwave, quantum-effect, hot- electron, and photonic devices. (cid:114) Part III, Chapters 11–15, deals with processing technology from crystal growth to impurity doping. We present the theoretical and practical aspects of the major steps in device fabrication with an emphasis on integrated devices. vii KEY FEATURES Each chapter includes the following features: (cid:114) The chapter starts with an overview of the topical contents. A list of covered learning goals is also provided. (cid:114) The third edition contains many worked-out examples that apply basic concepts to specific problems. (cid:114) A chapter summary at the end of each chapter summarizes the important concepts and helps the student review the content before tackling the homework problems that follow. (cid:114) The book includes about 250 homework problems. Answers to odd-numbered problems with numerical solutions are provided in Appendix L. COURSE DESIGN OPTIONS The third edition can provide greater flexibility in course design. The book contains enough material for a full-year sequence in device physics and processing technology. Assuming three lectures per week, a two- semester sequence can cover Chapters 0–7 in the first semester, leaving Chapters 8–15 for the second semester. For a three-quarter sequence, the logical breakpoints are Chapters 0–5, Chapters 6–10, and Chapters 11–15. A two-quarter sequence can cover Chapters 0–5 in the first quarter. The instructor has several options for the second quarter. For example, covering Chapters 6, 12, 13, 14 and 15 produces a strong emphasis on MOSFET and related process technologies, while covering Chapters 6–10 emphasizes all major devices. For a one-quarter course on semiconductor device processing, the instructor can cover Section 0.2 and Chapters 11–15. A one-semester course on basic semiconductor physics and devices can cover Chapters 0–7. A one- semester course on microwave and photonic devices can cover Chapters 0–3, and 7–10. For students with some familiarity with semiconductor fundamentals, a one-semester course on MOSFET physics and technology can cover Chapters 0, 5, 6, and 11–15. Of course, there are many other course design options depending on the teaching schedule and the instructor’s choice of topics. TEXTBOOK SUPPLEMENTS (cid:114) Instructor’s Manual. A complete set of detailed solutions to all the end-of- chapter problems has been prepared. These solutions are available free to all adopting faculty. (cid:114) The figures used in the text are available to instructors in electronic format, from the publisher. More information is available at the publisher’s website: http: //www.wiley.com/college/sze viii