Preface to First Edition xi
Preface to Second Edition xiii
Acknowledgements xvii
1 Electron Spectroscopy: Some Basic Concepts 1
1.1 Analysis of Surfaces 1
1.2 Notation 3
1.2.1 Spectroscopists’ Notation 3
1.2.2 X?ray Notation 4
1.3 X?ray Photoelectron Spectroscopy 4
1.4 Auger Electron Spectroscopy (AES) 8
1.5 Scanning Auger Microscopy 12
1.6 The Depth of Analysis in Electron Spectroscopy 13
1.7 Comparison of XPS and AES/SAM 16
1.8 The Availability of Surface Analytical Equipment 17
2 Electron Spectrometer Design 19
2.1 Introduction 19
2.2 The Vacuum System 19
2.3 X?ray Sources for XPS 22
2.3.1 Choice of X?ray Anode 23
2.3.2 X?ray Monochromators 27
2.3.3 Synchrotron Sources 30
2.4 The Electron Gun for AES 31
2.4.1 Electron Sources 31
2.4.1.1 Thermionic Emitter 32
2.4.1.2 Lanthanum Hexaboride Emitter 32
2.4.1.3 Cold Field Emitter 32
2.4.1.4 Hot Field Emitter 33
2.4.1.5 Comparison of Electron Emitters for AES 34
2.4.2 The Electron Column 35
2.4.3 Spot Size 35
2.5 Analysers for Electron Spectroscopy 37
2.5.1 The Cylindrical Mirror Analyser 38
2.5.2 The Hemispherical Sector Analyser 41
2.5.2.1 CAE Mode of Operation 42
2.5.2.2 CRR Mode of Operation 44
2.5.2.3 Comparison of CAE and CRR Modes 46
2.5.2.4 The Transfer Lens 47
2.5.3 Calibration of the Electron Spectrometer Energy Scale 48
2.6 Near Ambient Pressure XPS 49
2.7 Detectors 52
2.7.1 Channel Electron Multipliers 52
2.7.2 Microchannel Plates 54
2.7.3 Two?Dimensional Detectors 54
2.7.3.1 The Resistive?Anode Detector 55
2.7.3.2 The Delay?Line Detector 55
2.8 Small Area XPS 56
2.8.1 Lens?Defined Small Area XPS 56
2.8.2 Source-defined Small Area Analysis 57
2.9 XPS Imaging and Mapping 57
2.9.1 Serial Acquisition 58
2.9.2 Parallel Acquisition 59
2.9.2.1 Parallel Imaging Using a Hemispherical Spectrometer 59
2.9.2.2 Parallel Imaging Using a Spherical Mirror Analyser 60
2.9.2.3 Spatial Resolution and Chemical Imaging 61
2.10 Angle Resolved XPS 64
2.11 Automation 66
3 The Electron Spectrum: Qualitative and Quantitative Interpretation 69
3.1 Introduction 69
3.2 Qualitative Analysis 69
3.2.1 Unwanted Features in Electron Spectra 72
3.2.2 Data Acquisition 72
3.2.2.1 Core Level Spectra 72
3.2.2.2 Valence Band Spectra 73
3.3 Chemical State Information 74
3.3.1 X?ray Photoelectron Spectroscopy 74
3.3.2 Peak Fitting of XPS Spectra 78
3.3.3 Auger Electron Spectroscopy 81
3.3.4 X?AES 82
3.3.5 Chemical State Plots 84
3.3.6 Shakeup Satellites 86
3.3.7 Multiplet Splitting 87
3.3.8 Plasmons 87
3.4 Quantitative Analysis 88
3.4.1 Quantification in XPS 89
3.4.1.1 Calculating Atomic Concentration 89
3.4.1.2 Measuring Peak Intensity 92
3.4.2 Quantification in AES 94
4 Compositional Depth Profiling 97
4.1 Introduction 97
4.2 Non?destructive Depth Methods 98
4.2.1 Measurements at a Single Emission Angle 98
4.2.2 Angle Resolved XPS Measurements 99
4.2.3 Measurement of Overlayer Thickness Using ARXPS 101
4.2.4 Elastic Scattering 103
4.2.5 Multilayer Thickness Calculations Using ARXPS 104
4.2.6 Compositional Depth Profiles from ARXPS Measurements 107
4.2.7 Variation of Analysis Depth with Electron Kinetic Energy 110
4.2.8 Background Analysis 112
4.3 Depth Profiling by Sputtering with Energetic Ions 115
4.3.1 The Sputtering Process 115
4.3.2 Experimental Method 116
4.3.3 The Nature of the Ion Beam 118
4.3.3.1 Noble Gas Ions 118
4.3.3.2 Cluster Ions 119
4.3.3.3 Metal Ions 121
4.3.4 Sputter Yield and Etch Rate 122
4.3.5 Factors Affecting the Etch Rate 123
4.3.5.1 Material 123
4.3.5.2 Ion Current 123
4.3.5.3 Ion Energy 123
4.3.5.4 Nature of the Ion Beam 124
4.3.5.5 Angle of Incidence 124
4.3.6 Factors Affecting the Depth Resolution 124
4.3.6.1 Ion Beam Characteristics 124
4.3.6.2 Crater Quality 125
4.3.6.3 Beam Impurities 125
4.3.6.4 Information Depth 126
4.3.6.5 Original Surface Roughness 127
4.3.6.6 Induced Roughness 127
4.3.6.7 Preferential Sputtering 127
4.3.6.8 Redeposition of Sputtered Material 128
4.3.7 Calibration 128
4.3.8 Ion Gun Design 128
4.3.8.1 Electron Impact Ion Guns 128
4.3.8.2 Argon?Cluster Ion Guns 129
4.3.8.3 Liquid Metal Ion Guns 131
4.4 Sectioning 131
4.4.1 FIB Sectioning 131
4.4.2 Angle Lapping 132
4.4.3 Ball Cratering 133
5 Multi?technique Analysis 135
5.1 Introduction 135
5.2 Ultraviolet Photoelectron Spectroscopy (UPS) 135
5.3 Low Energy Ion Scattering Spectroscopy (LEISS) 137
5.4 Reflection Electron Energy Loss Spectroscopy (REELS) 139
5.4.1 Elastic Scattering 140
5.4.2 Inelastic Scattering 141
5.5 Work Function Measurements 142
5.6 Energy Dispersive X?ray Analysis (EDX) 143
6 The Sample 145
6.1 Sample Handling 145
6.2 Sample Preparation 147
6.3 Sample Mounting 149
6.4 Sample Stability 149
6.5 Contamination and Damage During Analysis 151
6.6 Controlling Sample Charging 152
6.6.1 Sample Charging in XPS 152
6.6.2 Sample Charging in AES 154
7 Applications of Electron Spectroscopy in Materials Science 157
7.1 Introduction 157
7.2 Metallurgy 157
7.2.1 Grain Boundary Segregation 158
7.2.2 Electronic Structure of Metallic Alloys 160
7.2.3 Surface Engineering 163
7.3 Corrosion Science 168
7.4 Ceramics 176
7.5 Microelectronics and Semiconductor Materials 181
7.5.1 Mapping Semiconductor Devices Using AES 182
7.5.2 XPS Failure Analysis of Microelectronic Devices 186
7.5.3 Depth Profiling of Semiconductor Materials 188
7.5.3.1 Transistor Gate Dielectrics 188
7.5.3.2 Inorganic Chemical State Profiling 189
7.5.3.3 Organic Semiconductor Profiling 190
7.6 Polymeric Materials 193
7.7 Adhesion Science 202
7.8 Nanotechnology 210
7.9 Biology 215
7.10 Energy 219
8 Comparison of XPS and AES with Other Analytical Techniques 223
Glossary 229
Bibliography 239
Appendix 1 247
Auger Electron Energies 247
Appendix 2 249
Table of Binding Energies Accessible with Al Kα Radiation 250
Appendix 3 255
Documentary Standards in Surface Analysis 255
The Scope of TC201 255
The Purpose of TC201 255
International Standards Relevant to Electron Spectroscopies 256
Index 259
