Foreword ....................................................... xi
Preface ...................................................... xiii
Acknowledgments ............................................... xvi
List of Constants ............................................ xvii
1 Introduction ............................................... 1
1.1 Matter and The Mass Spectrometer ........................... 1
1.2 Secondary Ion Mass Spectrometry ............................ 4
1.2.1 History ............................................. 6
1.2.2 Physical Basis ...................................... 8
1.2.2.1 Sensitivity and Detection Limits ................ 9
1.2.3 Application Fields ................................. 12
1.3 Summary ................................................... 18
SECTION I. PRINCIPLES .......................................... 21
2 Properties of Atoms, Ions, Molecules, and Solids .......... 23
2.1 The Atom .................................................. 23
2.1.1 Atomic Structure .................................. 23
2.1.1.1 Atomic Mass .................................... 25
2.1.1.2 Atomic Density ................................. 27
2.2 Electronic Structure of Atoms and Ions .................... 27
2.2.1 Stationary States .................................. 28
2.2.1.1 Quantum Numbers ................................ 28
2.2.1.2 Spectroscopic and X-ray Notation ............... 29
2.2.1.3 Ionization Potential and Electron Affinity ..... 31
2.2.2 Bonding and the Resulting Properties of Solids ..... 32
2.2.2.1 Bands and the Density of States ................ 34
2.2.2.2 Work Function .................................. 35
2.2.2.3 Image Field .................................... 36
2.2.2.4 Electronic Excitation .......................... 36
2.3 Summary ................................................... 42
3 Sputtering and Ion Formation .............................. 44
3.1 The Fundamentals of SIMS .................................. 44
3.1.1 Secondary Ion Generation ........................... 45
3.2 Sputtering ................................................ 46
3.2.1 Sputtering by Ion Impact ........................... 47
3.2.1.1 Linear Cascade Model ........................... 50
3.2.1.2 Other Sputtering Models ........................ 54
3.2.1.3 Simulations .................................... 60
3.2.2 Sputter Rates and Sputter Yields ................... 67
3.2.2.1 Sputter Yield Dependence on Primary Ion
Conditions ..................................... 69
3.2.2.2 Sputter Yield Dependence on Substrate .......... 76
3.2.3 Sputter-induced damage ............................. 81
3.2.3.1 Recoil Implantation, Cascade Mixing,
Diffusion, and Segregation ..................... 83
3.2.3.2 Substrate Amorphization and
Re-crystallization ............................. 85
3.2.3.3 Surface Roughening and Surface Smoothing ....... 86
3.3 Ionization/Neutralization ................................. 88
3.3.1 Ion-Solid Interactions ............................. 90
3.3.2 Secondary Ion Yields ............................... 93
3.3.2.1 Ionization Potential and Electron Affinity ..... 95
3.3.2.2 Matrix Effects ................................. 97
3.3.2.3 Electronic Excitation ......................... 113
3.3.3 Models for Atomic Secondary Ions .................. 121
3.3.3.1 LTE Formalism ................................. 123
3.3.3.2 Bond Breaking Model ........................... 124
3.3.3.3 Kinetic Emission Model ........................ 129
3.3.4 Models for Molecular Secondary Ions ............... 130
3.3.4.1 Models for Molecular Ion Emission in SIMS ..... 132
3.3.4.2 Models for Molecular Ion Emission in
MALD1 ......................................... 135
3.4 Summary .................................................. 138
SECTION II PRACTICES .......................................... 145
4 Instrumentation Used in SIMS ............................. 147
4.1 The Science of Measurement ............................... 147
4.1.1 SIMS in its various forms ........................ 148
4.1.1.1 Static SIMS ................................... 148
4.1.1.2 Dynamic SIMS .................................. 149
4.1.1.3 Cluster Ion SIMS .............................. 150
4.2 Hardware ................................................. 151
4.2.1 Vacuum ............................................ 152
4.2.1.1 Vacuum and the Kinetic Theory of Gases ........ 153
4.2.1.2 Pumping Systems ............................... 156
4.2.2 Primary Ion Columns ............................... 159
4.2.2.1 Ion Sources ................................... 161
4.2.3 Secondary Ion Columns ............................. 167
4.2.3.1 Mass Filters .................................. 170
4.2.3.2 Energy Filters ................................ 182
4.2.3.3 Detectors ..................................... 184
4.3 Summary .................................................. 191
5 Data Collection and Processing ........................... 195
5.1 The Art of Measurement ................................... 195
5.1.1 Data Formats and Definitions ..................... 196
5.1.1.1 Mass Spectra .................................. 197
5.1.1.2 Depth Profiling ............................... 201
5.1.1.3 Imaging ....................................... 204
5.2 Sample Preparation and Handling .......................... 208
5.2.1 Preparation in the Materials Sciences ............. 209
5.2.2 Preparation in the Earth Sciences ................. 210
5.2.3 Preparation in the Biosciences .................... 212
5.2.4 Sample Handling ................................... 213
5.3 Data Collection .......................................... 215
5.3.1 Secondary Ion Mass, Energy, and Intensity
Scales ............................................ 216
5.3.1.1 Referencing the Mass, Energy, and Intensity
Scales ........................................ 216
5.3.1.2 Charge Buildup ................................ 218
5.3.1.3 Isobaric Interferences ........................ 221
5.3.2 Instrument Operation Modes ........................ 225
5.3.2.1 Primary Ion Beam Operation Modes .............. 225
5.3.2.2 Secondary Ion Imaging Modes ................... 231
5.3.2.3 The O2 Leak Methodology ....................... 233
5.3.2.4 Depth Profiling and Related Aspects ........... 234
5.4 Data Processing .......................................... 248
5.4.1 Spectral Identification ........................... 249
5.4.1.1 Atomic and Unfragmented Molecular Emissions ... 249
5.4.1.2 Heavily Fragmented Molecular Emissions ........ 250
5.4.2 Quantification of the Depth Scale ................. 251
5.4.2.1 Ex situ Methods ............................... 254
5.4.2.2 In situ Methods ............................... 256
5.4.3 Quantification of the Concentration Scale ......... 259
5.4.3.1 The RSF Method ................................ 260
5.4.3.2 Fabrication of Reference Materials ............ 265
5.5 Summary .................................................. 268
Appendix A .................................................... 273
A.l Periodic Table of the Elements ........................... 273
A.2 Isotopic Masses, Natural Isotope Abundances, Atomic
Weights, and Mass Densities of the Elements .............. 273
A.3 1st and 2nd Ionization Potentials and Electron
Affinities of the Elements ............................... 280
A.4 Work-Function Values of Elemental Solids ................. 283
A.5 SIMS Detection Limits of Selected Elements ............... 286
A.6 Charged Particle Beam Transport .......................... 288
A.6.1 Ion Beam Trajectories .............................. 288
A.6.1.1 Liouville's Theorem ........................... 289
A.6.1.2 Phase Space Dynamics .......................... 289
A.6.1.3 Ray Tracing Methods ........................... 289
A.6.2 Optical Properties ................................ 290
A.6.2.1 Aberrations ................................... 290
A.6.2.2 Diffraction and the Diffraction Limit ......... 292
A.7 Some Statistical Distributions of Interest ............... 293
A.7.1 Gaussian Distribution ............................. 294
A.7.2 Poisson Distribution .............................. 294
A.7.3 Lorentzian Distributions .......................... 294
A.8 SIMS Instrument Designs .................................. 294
A.8.1 Physical Electronics 6600 ......................... 295
A.8.2 ASI SHRIMP I, II, and IV .......................... 296
A.8.3 SHRIMP RG ......................................... 297
A.8.4 Cameca IMS-1280 ................................... 298
A.8.5 Cameca IMS 7f ..................................... 299
A.8.6 Cameca nanoSIMS 50 ................................ 300
A.8.7 Ion-Tof TOF-SIMS 5 ................................ 302
A.8.8 Physical Electronics mno-SIMS ..................... 303
A.8.9 Ionoptika J105-3D Chemical Imager ................. 303
A.8.10 Q-Star Chemical Imager ............................ 304
A.8.11 SIMS Instrument Capability Table .................. 305
A.8.12 SIMS Instrument/Component Vendor List ............. 308
A.9 Additional SIMS Methods of Interest ...................... 311
A.9.1 Matrix Transferable RSFs .......................... 312
A.9.2 The Infinite Velocity Method ...................... 313
A.9.3 Lattice Valency Model ............................. 314
A.9.4 PCOR-SIMS™ Method ................................. 315
A.10 Additional Spectroscopic/Spectrometric Techniques ........ 316
A.10.1 Photon Spectroscopies ............................. 317
A.10.1.1 IR, RAIRS, ATR, and DRIFTS .................... 317
A.10.1.2 Raman, SERS, and TERS ......................... 318
A.10.1.3 EDX, WDS, and LEXES ........................... 319
A.10.1.4 XRF and TXRF .................................. 320
A.10.1.5 VASE .......................................... 320
A.10.2 Electron Spectroscopies ........................... 321
A.10.2.1 XPS and UPS ................................... 321
A.10.2.2 AESandSAM ..................................... 321
A.10.2.3 EELS, REELS, and HREELS ....................... 322
A.10.3 Ion Spectroscopies/Spectrometries ................. 322
A.10.3.1 GD-MS, GD-OES, and 1CP-MS ..................... 322
A.10.3.2 MALDI and ESI-MS .............................. 323
A.10.3.3 SNMS and RIMS ................................. 324
A.10.3.4 APT ........................................... 324
A.10.3.5 Ion Scattering Methods ........................ 325
A.10.3.6 ERD, NRA, NAA, and PIXE ....................... 326
A.11 Additional Microscopies .................................. 327
A.ll.l SEM ............................................... 328
A.11.2 HIM ............................................... 328
A.11.3 ТЕМ ............................................... 329
A.11.4 SPM (AFM and STM)-Based Techniques ................ 329
A.12 Diffraction/Reflection Techniques of Interest ............ 331
A.12.1 XRD and GID ....................................... 332
A.12.2 GID ............................................... 332
A.12.3 XRR ............................................... 333
A.12.4 LEED .............................................. 333
A.12.5 RHEED ............................................. 333
A.12.6 Neutron Diffraction ............................... 333
Technique Acronym List ........................................ 335
Abbreviations Commonly used in SIMS ........................... 338
Glossary of Terms ............................................. 340
Questions and Answers ......................................... 347
References .................................................... 350
Index ......................................................... 359
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