The Electrical Characterization of Semiconductors: Majority Carriers and Electron States
P. BLOOD and J.W. ORTON
Philips Research Laboratories, Redhill, SurreyRHI 5HA, UK
ACADEMIC PRESS Harcourt Brace Jovanovich. Publishers London San Diego New York Boston Sydney Tokyo Toronto
Contents
Preface viii List of Commonly Used Symbols xi
1 Introduction 1 1.1 Semiconductor Characterization 1 1.2 Majority Carrier Properties and Electron States 6
2 Measurement of Resistivity 13 2.1 Introduction 13 2.2 Samples with Ohmic Contacts 14 2.3 The Four-Point Probe 26 2.4 Spreading Resistance 53 2.5 Contactless Methods 74 2.6 Relationship Between Carrier Density, Mobility and
Resistivity 82 2.7 Summary 89
3 Galvanomagnetic Effects 93 3.1 Introduction 93 3.2 The Hall Effect—Elementary Survey 95 3.3 Non-uniform Current Distribution 108 3.4 More Advanced Theory 114 3.5 The Hall Scattering Factor 122 3.6 Detailed Analysis of Temperature-dependent Hall Data 131 3.7 Magnetoresistance—Measurement of Carrier Mobility 151 3.8 Measurements on High Resistivity Material—Semi-
insulating GaAs 159 3.9 Measurements on Two-dimensional Electron Gas
Structures 167 3.10 Summary 177
4 Resistivity and Hall Effect Profiling of Non-uniform Material 181 4.1 Introduction : '. 181 4.2 Layer Removal 182 4.3 Resistivity Profiling with the Four-point Probe 188 4.4 Hall Effect Profiling 191 4.5 Magnetoresistance Mobility Profiling 203 4.6 Spreading Resistance Profiling 206
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vi Contents
4.7 Summary 217
5 Capacitance-Voltage Profiling 220
5.1 Introduction 220 5.2 Depletion Capacitance 221 5.3 Profiling Methods 242 5.4 Summary 264
6 Interpretation of Capacitance-Voltage Profiles 266 6.1 Introduction 266 6.2 Departures from the Depletion Approximation 267 6.3 Instrumental Depth Resolution and Accuracy 282 6.4 Capacitance-Voltage Profiling of Multilayer and
Quantum Well Structures 288 6.5 Influence of Deep States 295 6.6 Relation between Hall Effect and Capacitance-Voltage
Measurements 308 6.7 Influence of the Test Diode 315 6.8 Verification of Capacitance-Voltage Profiles 331
7 Deep States in Depletion Regions 336 7.1 Introduction 336 7.2 Rate Equations 339 7.3 Observation of Deep States 350 7.4 Behaviour of Deep States in Depletion Regions 355 7.5 Depletion Capacitance and Deep States 369 7.6 Space Charge Transients 371 7.7 Transient Currents in Depletion Regions 380 7.8 Currents in Undepleted Samples: Transient Conductivity 393 7.9 Summary 397
8 Deep Level Transient Spectroscopy of Majority Carrier Traps 399 8.1 Introduction 399 8.2 Deep Level Transient Spectroscopy 400 8.3 Material Characterization by DLTS 413 8.4 Interpretation of Arrhenius Plot 426 8.5 Performance of Rate Window Systems 439 8.6 Other Applications of DLTS Techniques 456 8.7 Summary 464
9 Other Techniques for Study of Majority Carrier Traps 466 9.1 Introduction 466
Contents vii
9.2 Thermally Stimulated Conductivity, Current and Capacitance 467
9.3 Photo-Induced Current Transient Spectroscopy 478 9.4 Admittance Spectroscopy 492 9.5 Capacitance Transients at Large Trap Concentrations . 517 9.6 Summary 522
10 Thermal Emission from Minority Carrier Traps 524 10.1 Introduction 524 10.2 Optical DLTS (ODLTS) 525 10.3 Junction DLTS 554 10.4 Minority Carrier Transient Spectroscopy (MCTS) 581 10.5 Summary 594
11 Deep State Carrier Capture Cross Sections 596 11.1 Introduction 596 11.2 Majority Carrier Capture at a Majority Carrier Trap.. 600 11.3 Minority Carrier Capture at a Minority Carrier Trap . 636 11.4 Double Pulse Techniques 642 11.5 Summary 646
12 Depth Profiling of Deep States 649 12.1 Introduction 649 12.2 C(F) Methods 650 12.3 Capacitance-Voltage Profiler Methods 654 12.4 Trap Profiling using DLTS Systems 661 12.5 Reverse Pulse Deep Level Transient Spectroscopy
(RDLTS) 674 12.6 Summary 679
13 Optically Induced Emission from Deep States 681 13.1 Introduction 681 13.2 Use of Depletion Regions 683 13.3 Steady State Methods 687 13.4 Optically Induced Charge Transients 696 13.5 Deep Level Optical Spectroscopy (DLOS) 698 13.6 Optical Admittance Spectroscopy 705 13.7 Summary 708
References 711
Index 727
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