Cluster Secondary Ion Mass Spectrometry Principles and Applications

Christine M. Mahoney, PhD, is a recognized expert and leader in the field of Secondary Ion Mass Spectrometry (SIMS). Throughout her career, she has focused primarily on the application of SIMS to molecular targets, and has played a significant role in the development of cluster SIMS for polymer depth profiling applications. She received her PhD in analytical chemistry from SUNY Buffalo in 1993. She spent the following eight years at the National Institute of Standards and Technology (NIST), where much of her molecular depth profiling work was performed. Christine is currently employed as a senior research scientist at the Environmental Molecular Sciences Laboratory (EMSL) at Pacific Northwest National Laboratory (PNNL), where she continues to lead research in the field of SIMS.

1.1 Secondary Ion Mass Spectrometry in a nutshell 

1.1.1  SIMS imaging 

1.1.2  SIMS depth profiling

1.2  Basic Cluster SIMS Theory: 

1.3  Cluster SIMS:  An early history

1.3.1  Nonlinear sputter yield enhancements

1.3.2  Molecular Depth Profiling

1.4  Recent Developments

1.5  About this book

1.6 References 

1.7 Chapter 1 Figure Captions: .

Chapter 2. Cluster SIMS of Organic Materials: Theoretical Insights 

2.1  Introduction 

2.2 Molecular Dynamics Simulations of Sputtering with Clusters 

2.2.1 The cluster effect 

2.2.2 Computer simulations and the molecular dynamics “experiment” 

2.2.3 Light and heavy element clusters, and the importance of mass matching 

2.2.4 Structural effects in organic materials 

2.2.4.1 Amorphous molecular solids and polymers 

2.2.4.2 Organic crystals 

2.2.4.3  Thin organic layers on metal substrates 

2.2.4.4  Hybrid metal-organic samples 

2.2.5  Induced chemistry 

2.2.6 Multiple hits and depth profiling 

2.2.7  From small polyatomic projectiles to massive clusters 

2.2.7.1  Light-element clusters 

2.2.7.2.  Large argon clusters 

2.2.7.2.  Massive gold clusters 

2.3  Other models 

2.3.1 Analytical models: From linear collision cascades to fluid dynamics 

2.3.2   Recent developments and hybrid approaches 

2.4  Conclusions 

2.5  References 

2.6  Chapter 2 Figure Captions: 

Chapter 3. Ion Sources used for Secondary Ion Mass Spectrometry 

3.1  Introduction 

3.2  Research Needs that have influenced the Development of Primary Ion Sources for Sputtering 

3.3  Functional Aspects of Various Ion Sources 

3.3.1  Energy spread in the beam 

3.3.2  Point-source ionization: 

3.3.3  Stable emission 

3.3.4  Ion Reactivity 

3.3.5  Source Lifetime 

3.3.6  Penetration Depth and Surface Energy Spread of the Projectile 

3.4  Atomic Ion Sources 

3.4.1  Field Emission 

3.4.2  Radio Frequency Ionization 

3.4.3  Electron Impact 

3.4.4  Thermal Ionization 

3.4.5  DC-glow discharge 

3.4.6  Sputtering 

3.5  Molecular Ion Sources 

3.5.1  Field Emission 

3.5.2  Radio Frequency Discharge 

3.5.3  Electron Impact 

3.5.4  DC glow discharge 

3.5.5  Sputtering 

3.6  Cluster Ion Sources 

3.6.1  Jets and Electron Impact (massive gas clusters) 

3.6.2  Field Emission 

3.7  Summary 

3.8  References 

3.9  Figure captions 

Chapter 4. Surface Analysis of Organic Materials with Polyatomic Primary Ion Sources 

4.1  Introduction 

4.2  Cluster Sources in Static SIMS 

4.2.1 A brief introduction to Static SIMS 

4.2.2  Analysis beyond the static limit 

4.2.3  Increased Ion Yields 

4.2.4  Decreased Charging 

4.2.5  Surface Cleaning 

4.3  Experimental Considerations 

4.3.1 When to Employ Cluster Sources as Opposed to Atomic Sources 

4.3.2  Type of Cluster Source Used 

4.3.2.1 Liquid Metal Ion Gun (LMIG) 

4.3.2.2 C60+ for mass spectral analysis and imaging applications 

4.3.2.3. The Gas Cluster Ion Beam (GCIB) 

4.3.2.4.  Au4004+ 

4.3.2.5.  Other sources

4.3.3 Cluster Size Considerations 

4.3.4  Beam energy 

4.3.5  Sample temperature 

4.3.6 Matrix-enhanced and metal-assisted cluster SIMS 

4.3.7  Matrix Effects 

4.3.8  Other important factors 

4.4  Data analysis methods 

4.4.1  Principal Components Analysis 

4.4.1.1  Basic principles of PCA 

4.4.1.2  Examples of PCA in the literature 

4.4.2 Gentle SIMS (G-SIMS) 

4.5  Other relevant surface mass spectrometric based methods 

4.5.2  Desorption Electrospray Ionization (DESI) 

4.5.3  Plasma desorption ionization methods 

4.5.4  Electrospray droplet impact source for SIMS 

4.6  Advanced Mass Spectrometers for SIMS 

4.7  Conclusions 

4.8  Appendix 

4.8.1 Useful Lateral Resolution 

4.9 References 

4.10  Chapter 4 Figure Captions: 

Chapter 5. Molecular Depth profiling with cluster ion beams 

5.1 Introduction 

5.2 Historical Perspectives 

5.3 Depth profiling in heterogeneous systems 

5.3.1  Introduction 

5.3.2  Quantitative depth profiling 

5.3.3  Reconstruction of 3-D images 

5.3.4  Matrix effects in heterogeneous systems 

5.4 Erosion Dynamics Model of Molecular Sputter Depth Profiling 

5.4.1 Parent molecule dynamics 

5.4.2 Constant erosion rate 

5.4.3 Fluence dependent erosion rate 

5.4.4 Using mass spectrometric signal decay to measure damage parameters 

5.4.5  Surface transients 

5.4.6  Fragment dynamics 

5.4.7  Conclusions 

5.5 The chemistry of atomic ion beam irradiation in organic materials 

5.5.1  Introduction 

5.5.2  Understanding the basics of ion irradiation effects in molecular solids

5.5.3  Ion beam irradiation and the gel-point

5.5.4  The chemistry of cluster ion beams

5.5.5  Chemical structure changes and corresponding changes in depth profile shapes

5.6  Optimization of experimental parameters for organic depth profiling 

5.6.1  Introduction 

5.6.2  Organic delta layers for optimization of experimental parameters 

5.6.3  Sample Temperature 

5.6.4  Understanding the role of beam energy during organic depth profiling 

5.6.5  Optimization of incidence angle 

5.6.6  Effect of sample rotation 

5.6.7  Ion source selection 

5.6.7.1  SF5+and other small cluster ions 

5.6.7.2   C60n+ and similar carbon cluster sources 

5.6.7.3  The gas cluster ion beam (GCIB) 

5.6.7.4 Low energy reactive ion beams 

5.6.7.5 Electrospray droplet impact (EDI) source for SIMS 

5.6.7.6  Liquid metal ion gun clusters (Bi3+ and Au3+) 

5.6.8   C60+ / Ar+ co-sputtering 

5.6.9  Chamber backfilling with a free-radical inhibitor gas 

5.6.10  Other considerations for organic depth profiling experiments 

5.6.11  Molecular depth profiling: novel approaches and methods 

5.7  Conclusions 

5.8  References 

5.9 Chapter 5 Figure captions 

Chapter 6. Three-dimensional Imaging with Cluster Ion Beams 

6.1 Introduction 

6.2 General Strategies 

6.2.1  Three-dimensional Sputter Depth Profiling 

6.2.2  Wedge Bevelling 

6.2.3  Physical cross sectioning 

6.2.4 FIB-TOF  Tomography 

6.3 Important considerations for accurate 3-D respresentation of data 

6.3.1  Beam rastering techniques 

6.3.2  Geometry effects 

6.3.3. Depth scale calibration 

6.4 Three-dimensional image reconstruction 

6.5 Damage and altered layer depth 

6.6 Biological samples 

6.7 Conclusions 

6.8  References 

6.9  Chapter 6 Figure captions: 

Chapter 7. Cluster Secondary Ion Mass Spectrometry (SIMS)  for Semiconductor and Metals Depth Profiling 

7.1  Introduction 

7.2  Primary Particle-Substrate Interactions 

7.2.1 Collisional Mixing and Depth Resolution 

7.2.2 Transient Effects 

7.2.3 Sputter-Induced Roughening 

7.3 Possible Improvements in SIMS Depth Profiling – The Use of Cluster Primary ion Beams 

7.4 Development of Cluster SIMS For Depth Profiling Analysis 

7.4.1 CF3+ Primary Ion Beams 

7.4.2 NO2+ and O3+  Primary Ion Beams 

7.4.3 SF5+ Polyatomic Primary Ion Beams 

7.4.4 CsC6- and C8- Depth Profiling 

7.4.5 Os3(CO)12 and Ir4(CO)12 Primary Ion Beams 

7.4.6 C60+ Primary Ion Beams 

7.4.7 Massive Gaseous Cluster Ion Beams 

7.5 Conclusions and Future Prospects 

7.6 References 

7.7  Chapter 7 Figure Captions: 

Chapter 8. Cluster ToF-SIMS imaging and the characterization of biological materials

8.1  Introduction 

8.2 The capabilities of ToF-SIMS for biological analysis

8.3 New hybrid ToF-SIMS instruments 

8.3.1  Introduction 

8.3.2. Benefits of New DC beam Technologies

8.4  Challenges in the use of ToF-SIMS for biological analysis 

8.4.1 Sample handling of biological samples for analysis in vacuum

8.4.2 Analysis is limited to small to medium size molecules

8.4.3 Ion yields limit useful spatial resolution for molecular analysis to not much better than 1 µm

8.4.4 Matrix effects inhibit application in discovery mode and greatly complicate quantification

8.4.5  The complexity of biological systems can result in data sets that need multivariate analysis (MVA) to unravel

8.5  Examples of biological studies using cluster-ToF-SIMS 

8.5.1 Analysis of Tissue 

8.5.2 Drug location in tissue

8.5.3 Microbial mat - Surface and sub-surface analysis in streptomyces 

8.5.4 Cells 

8.5.5 Depth scale measurement 

8.5.6 High throughput bio-materials characterization

8.6 Final thoughts and future directions

8.7 References 

8.8 Chapter 8 Figure Captions

Chapter 9. Future Challenges and Prospects of Cluster SIMS 

9.1 Introduction 

9.2 The cluster niche 

9.3 Cluster types 

9.4 The challenge of massive molecular ion ejection 

9.4.1 Comparing with MALDI: the Gold Standard 

9.4.2  Particle impact techniques 

9.5 Ionization 

9.5.1 “Preformed” ions: 

9.5.2 Radical ions and ion fragments: 

9.5.3 Ionization processes for massive clusters 

9.6 Matrix effects and challenges in quantitative analysis 

9.7 SIMS Instrumentation 

9.7.1 Massive cluster ion (MCI) source technology 

9.8.  Prospects for biological imaging 

9.9 Conclusions 

9.10  References: 

9.11  Chapter 9 Figure Captions

The New copy of this book will include any supplemental materials advertised. Please check the title of the book to determine if it should include any access cards, study guides, lab manuals, CDs, etc.

The Used, Rental and eBook copies of this book are not guaranteed to include any supplemental materials. Typically, only the book itself is included. This is true even if the title states it includes any access cards, study guides, lab manuals, CDs, etc.