Front Cover 1
Developments in Surface Contamination and Cleaning: Cleaning Techniques 4
Copyright 5
Contents 6
Contributors 10
Preface 12
About the Editors 16
Chapter 1: How Green and Does it Clean: Methodologies for Assessing Cleaning Products for Safety and Performance 18
1. Background 19
2. Environmental Concerns 20
3. Green Cleaning 20
4. Regulatory Aspects 23
5. Product Selection 25
6. Green Assessment-What Makes a Product Green? 26
6.1. Pollution Prevention Options Assessment Tool (P2OASys) 27
6.2. Green Screen 28
6.2.1. Human Health Group I 33
6.2.2. Human Health Group II and II 33
6.2.3. Environmental Toxicity and Fate 33
6.2.4. Physical Hazards 33
6.2.5. Green Screen Process Steps 34
6.3. Environmental Protection Agency Design for the Environment 37
6.3.1. Acute Mammalian Toxicity 38
6.3.2. Carcinogenicity 38
6.3.3. Genetic Toxicity 38
6.3.4. Neurotoxicity 38
6.3.5. Repeated Dose Toxicity 38
6.3.6. Reproductive and Developmental Toxicity 38
6.3.7. Respiratory Sensitization 39
6.3.8. Skin Sensitization 39
6.3.9. Environmental Toxicity and Fate 39
6.3.10. Eutrophication 39
6.4. Green Seal Environmental Standard for Cleaning and Degreasing Agents (GS 34) 47
6.4.1. Toxic Compounds 47
6.4.2. Carcinogens and Reproductive Toxins 47
6.4.3. Corrosivity and Causticity 47
6.4.4. Skin and Eye Irritation 47
6.4.5. Flammability and Ignitability 47
6.4.6. VOC Content 48
6.4.7. Ozone Depletion 48
6.4.8. Toxicity to Aquatic Life 48
6.4.9. Aquatic Biodegradability 48
6.4.10. Eutrophication 48
6.4.11. Disposal 48
6.4.12. Animal Testing 48
6.5. Quick Guide for Tools 48
7. Performance Testing/Efficacy Evaluation 51
7.1. Basic Testing Process 53
7.1.1. Phase I Product Selection 53
7.1.2. Phase II Temperature and Concentration Studies 53
7.1.3. Phase III Mechanical Energy Studies 54
7.1.4. Phase IV Actual Product Cleaning Studies 55
7.1.5. Phase V Pilot Plant/Scale-Up Feasibility Studies 55
7.2. Case Studies 57
7.2.1. Case Study1-Shedding Some Light on Laboratory Versus Field Practices [22] 57
7.2.2. Case Study2-Thinking Outside the Cable Box-Wire & Cable Company Uses Floor Stripper on Cables [23]
7.2.3. Case Study3-A Gear Company Decides to Go all the ``Wayqueous´´-Greasing the Wheels for Regulatory Change and Resis... 77
7.3. Case Study Summary 80
8. Summary 80
Appendix A. Contact Information for Cleaning Products and Suppliers 81
Appendix B. Contact Information for Soils and Contaminants and Suppliers 84
References 85
Chapter 2: UV-Ozone Cleaning for Removal of Surface Contaminants 88
1. Introduction 88
2. Surface Contamination and Cleanliness Levels 89
3. Principles of UV-Ozone Cleaning 90
4. Process Variables 95
4.1. UV Sources 95
4.2. Distance from the Source 95
4.3. Precleaning 95
4.4. Types of Contaminants 96
4.5. Types of Substrates 96
5. Cleaning Systems 96
5.1. Costs 102
5.1.1. Examples of Cost Savings 102
6. Advantages and Disadvantages of UV-Ozone Cleaning 103
6.1. Advantages 103
6.2. Disadvantages 104
7. Applications 105
7.1. Semiconductor and Electronics Parts 106
7.2. Cleaning of Reference Masses 107
7.3. Solar Wind Sample Collectors 107
7.4. Metal Surfaces 107
7.5. Glass and Optical Materials 108
7.6. Probe Tips 109
7.7. Decontamination of Incubator Cabinets 109
7.8. Preparation of Samples for Trace Element Analysis 110
7.9. Polymer Surfaces 110
7.10. Textiles and Fabrics 111
8. Summary 111
References 85
Chapter 3: Use of Water Ice for Removal of Surface Contaminants 122
1. Introduction 122
2. Surface Contamination and Surface Cleanliness Levels 123
3. Theoretical Considerations 133
3.1. Phase Behavior 133
3.2. Mechanical Properties 134
3.3. Mechanism of Ice Blasting 136
4. Description of the Process 138
5. Cleaning Systems 139
5.1. Abrasive Medium Addition 143
6. Cost Considerations 143
7. Advantages and Disadvantages 145
7.1. Advantages 145
7.2. Disadvantages 145
8. Applications 146
8.1. Semiconductor Wafer Cleaning 146
8.2. Electronics and Photonics Applications 147
8.3. Automotive Components 147
8.4. Nuclear Applications 148
8.5. Deburring of Components 150
8.6. Recycling and Recovery 151
8.7. Facility Decommissioning 151
8.8. Restoration of Historic Building 151
8.9. Oil Field Equipment Cleaning 152
8.10. Cleaning Pipes 153
9. Summary and Conclusions 153
References 85
Chapter 4: Post-CMP Cleaning 162
1. Introduction 162
2. Forces on Particulate Contaminants in a Post-CMP Cleaning Process 164
2.1. van der Waals Forces 164
2.2. Double-Layer Interactions 167
3. Types of Post-CMP Cleaning Processes 168
3.1. Batch Cleaning 168
3.2. Single Wafer Cleaning 173
3.2.1. Brush Cleaning 173
4. Megasonic Cleaning 180
5. Cleaning Chemistries 186
5.1. Silicon Dioxide Post-CMP Cleaning 186
5.2. Tungsten Post-CMP Cleaning 191
5.3. Copper Post-CMP Cleaning 192
6. Summary 197
References 85
Chapter 5: A Brief Review of the Cleaning Process for Electronic Device Fabrication 202
1. Introduction 203
2. Cleaning of Inorganic Contamination 203
2.1. Neutral Particles 203
2.2. Ionically Bonded Particles 204
2.2.1. Ionic SRP 204
2.2.2. Ionic Trapping Process 206
2.3. Covalently Bonded Particles 207
2.3.1. Foreign Bonded Particles 207
2.3.2. Native Bonded Particles 208
2.3.2.1. Cleaning Solution Containing a Component with a Low Dissociation Constant 211
2.3.2.2. Stream Cleaning Solution 212
2.3.2.3. Spray Cleaning 213
2.4. Zeta Potential 213
2.4.1. Factors Affecting the Zeta Potential 215
2.4.1.1. pH 215
2.4.1.2. Effect of Concentration 215
2.4.2. Measurement of the Zeta Potential 216
3. Cleaning of Organic Contaminants 217
4. Effects of Surfactants in Cleaning Solutions 218
5. Wet Cleaning for Removing Trace Metals after Etching Process 220
5.1. Aluminum 221
5.2. Gold 222
5.3. Chromium 222
5.4. Indium Tin Oxide 222
5.5. Titanium Tungsten 222
5.6. Copper 222
5.7. Nickel 223
5.8. Gallium Arsenide 223
6. Silicon Product Wet Etching Process 223
6.1. Silica Isotropic and Anistropic Etching 224
6.2. Silicon Isotropic and Anisotropic Etching Process 224
6.3. Silicon Nitride 226
6.4. Dry Etching Process 226
6.5. Advantages and Disadvantages of Dry Versus Wet Etching 227
7. Summary and Conclusions 227
References 85
Index 230