Beam Effects, Surface Topography, and Depth Profiling in Surface Analysis

Transcription

1 Beam Effects, Surface Topography, and Depth Profiling in Surface Analysis Edited by Alvin W. Czanderna National Renewable Energy Laboratory Golden, Colorado Theodore E. Madey Rutgers, The State University ofnew Jersey Piscataway, New Jersey and Cedric J. Powell National Institute of Standards and Technology Gaithersburg, Maryland PLENUM PRESS NEW YORK AND LONDON

2 Contents 1. Photon Beam Damage and Charging at Solid Surfaces John H. Thomas III 1. Introduction 1 2. Electrostatic Charging of Samples in Photoemission Experiments Electrostatic Surface Charging Differential Surface Charging Lateral and In-Depth Charge Effects Small-Spot Analysis Charging Effects Energy Scale Calibration The Auger Parameter: Charge-Independent Chemical Identification Photon Damage Photon Absorption Processes Radiation Damage to Inorganic Materials Photon Damage to Polymers Closing Comments 34 References Electron Beam Damage at Solid Surfaces Carlo G. Pantano, Andrew S. D'Souza and Alan M. Then 1. Introduction Fundamentals Electronic Excitation Processes Electron-Stimulated Desorption Electron-Stimulated Adsorption Decomposition of Surface Layers and Thin Films 49 xiii

3 xiv Contents Oxidation of Surface Layers and Thin Films Thresholds for Sample Damage Resulting from Electronic Excitation Charging Insulators Electromigration in Insulators Electron-Beam-Induced Heating Electron Beam Effects in Auger Surface Analyses Physical Effects Contaminated, Oxidized, or Coated Surfaces Polymers Glasses Sputter Depth Profiles Microanalyses Recommendations References Review of Beam Damage in Electron Microscopy General Discussions of Electron Beam Damage in Surface Analysis Fundamentals of Electron-Stimulated Desorption Studies of Electron Beam Interactions at Solid Surfaces Charging of Insulators Resulting from Electron Beam Irradiation Electron Beam Damage in Glasses Electron Beam Damage during Surface Analysis Ion Beam Bombardment Effects on Solid Surfaces at Energies Used for Sputter Depth Profiling L. S. Dake, D. E. King, J. R. Pitts, anda. W. Czanderna 1. Introduction Overview Ion Beams and Solids: Topics Not Covered Definitions and Nomenclature Overview of lon-surface and Ion-Solid Interactions Ion Beam-Solid Interactions Introduction Ion Beam Reflection/Backscattering Penetration and Trapping Ion-Substrate Interactions 116

4 2.4. Mixing and Implantation of Material Ballistic Mixing Diffusional Mixing Processes Removalof Material Physical Sputtering SputterYields Differential Sputtering Altered Layer (Zone of Mixing) 133 Structural Changes Resulting from Ion Beam Bombardment Bond Stretching, Bond Breaking, and Surface Reconstruction from Ion Beam Bombardment Structural Changes as Nanotopography from Ion Beam Bombardment Surface Defect Formation from Ion Beam Bombardment Damage Depth and Defect Density from Ion Beam Bombardment Enhanced Diffusion and Changes in Electrical Properties from Ion Beam Bombardment 163 Physical Effects: Ion-Beam-Induced Topography Introduction Mechanisms for Topography Development Microscopic and Macroscopic Roughness EtchPits Pyramids Cones Whiskers Ripples and Corrugation Sputter-InducedRecrystallization Coalescence to Form Islands Swelling Smoothing Miscellaneous Results Topographical Differences in the Same Sample Topography of Kapton and Teflon after Atom Beam Bombardment Sputtering with Non-Noble-Gas Ions Annealing Sputter Damage Concluding Remarks 201 Compositional Changes and Chemical Effects Introduction 201 XV

5 xvi Contents 5.2. Organic Materials Alloys Ternary Alloys Semiconductors Metal Oxides Simple Metal Oxides Complex Oxides: Perovskites Complex Oxides: Glasses Compounds Calculations and Simulations Depth Resolution: Sample, Beam, and Instrumental Effects Introduction Nature and Condition of the Sample Ion Beam Bombardment Effects Instrumental Effects Ultimate and Practical Limits on Az Combined Beam Effects Applications Summary and Concluding Remarks 252 References 255 Appendix 1. Acronyms and Abbreviations Characterization of Surface Topography T. V. Vorburger, J. A. Dagata, G. Wilkening, and K. lizuka 1. Introduction Results Obtainable with Profiling Instruments Profile Recordings and Dimensional Measurement Surface Statistics Surface Parameters Statistical Functions Other Statistical Descriptors B and width Limits Stylus Instruments Height Resolution and Range Lateral Resolution and Range Stylus Load and Surface Deformation Other Distortions Calibration 299

6 Contents xvii 3.6. Applications Area Profiling with Stylus Instruments Optical Profiling Techniques Scanned Probe Microscopy Short History of Scanned Probe Microscopy Calibration and Characterization Instruments for Displacement Calibration Calibration Specimens for Displacement Instruments for Critical Dimensions and High Resolution Specimens for Critical Dimensions Other Types of Scanned Probe Microscopes Force-Based Methods (Mechanical) Methods Based on Other Probe-Sample Interactions Applications of SPM Measurements Data Storage Industries Microelectronics Industries Polymers and Coatings Industries Optical Element Industries Mechanical Parts Industries and Materials Science Electrochemical Science Future Directions: Techniques and Instrumentation Intercomparisons Conclusions 339 References Depth Profiling Using Sputtering Methods H. W. Werner and P. R. Boudewijn 1. Introduction Principle of Sputter Depth Profiling Methods for Sputter Depth Profiling Different Modes of Sputter Depth Profiling Planar Sputter Depth Profiling Crater-Wall, Tapered-Section, or Angular-Mapping Depth Profiling Comparison of Sputter Depth Profiling with Other Methods Consumptive Methods for Depth Profiling 362

7 Nonconsumptive Methods and Modes for Depth Profiling Physical Basis of the Sputtering Process Introduction Theory of the Sputtering Process Binary Collision Theory Classification of Sputtering Events Sputtering from Linear Collision Cascades Sputtering Yields (Experimental) Information Depth Processes Related to Sputtering Experimental Aspects Introduction Ion Beam Sources Time Needed to Obtain a Depth Profile Analysis of Sputter Depth Profiles Introduction Conversion of the Sputter Depth Profile of an Element X, /(X, t), into a Concentration Depth Profile c(z) Determination of the Depth Scale Conversion of the Measured Signal / into an Elemental Concentration c Artifacts in Sputter Depth Profiles Artifacts Related to the Interaction Process between Energetic Projectiles and the Solid Artifacts Related to the Properties of the Sample Artifacts Related to Instrumental Parameters Evaluation of a Measured Depth Profile Depth Resolution Detection Limit for a Given Element Application of Sputter Depth Profiling to Various Thin-Film Materials Stable Isotope Tracers Thin-Film Interdiffusion and Multilayer Analysis Corrosion and Oxidation Catalysts Polymer-Metal Interfaces Insulating Materials Semiconductor Materials Miscellaneous Applications Newcomers to Sputter-Depth-Profiling Techniques

8 Contents xix 6. Summary and Future Prospects 412 Acknowledgment 412 References 412 Index 421