Handbook of Physical Vapor Deposition (PVD) Processing

Handbook of Physical Vapor Deposition (PVD) Processing Donald M. Mattox AMSTERDAM BOSTON HEIDELBERG LONDON k^tj WilliЗ.ГП F^Wm NEW YORK OXFORD PARIS SAN DIEGO Щ Л. M A 1.ЖШШша, SAN FRANCISCO SINGAPORE SYDNEY TOKYO EA1 Al luxcw ELSEVIER William Andrew is an imprint of Elsevier Applied Science Publishers

Contents Preface to First Edition Preface to Second Edition Acknowledgements Acronyms Biography xix xxi xxiii xxv xlv Chapter 1: Introduction 1 1.1 Surface Engineering 1 1.1.1 Physical Vapor Deposition (PVD) Processes 2 1.1.2 Non-PVD Thin Film Atomistic Deposition Processes 6 1.1.3 Applications of Vacuum-deposited Materials 9 1.2 Thin Film Processing 12 1.2.1 Stages of Fabrication 12 1.2.2 Factors that Affect Film Properties 12 1.2.3 Scale-Up and Manufacturability 15 1.3 Process Documentation 16 1.3.1 Process Specifications 16 1.3.2 Manufacturing Process Instructions (MPIs) 18 1.3.3 Travelers 18 1.3.4 Equipment and Calibration Logs 19 1.3.5 Commercial/Military Standards and Specifications (Mil Specs) 20 1.4 Safety and Environmental Concerns 20 1.5 Units 21 1.5.1 Temperature Scales 22 1.5.2 Energy Units 22 1.5.3 Prefixes 22 1.5.4 The Greek Alphabet 22 1.6 Summary 23 Chapter 2: Substrate ("Real") Surfaces and Surface Modification 25 2.1 Introduction 25 2.2 Materials and Fabrication 26 2.2.1 Metals 26 V

vi Contents 2.2.2 Ceramics and Glasses 28 2.2.3 Polymers 30 2.3 Atomic Structure and Atom-particle Interactions 30 2.3.1 Atomic Structure and Nomenclature 30 2.3.2 Excitation and Atomic Transitions 32 2.3.3 Chemical Bonding 34 2.3.4 Probing and Detected Species 35 2.4 Characterization of Surfaces and Near-surface Regions 38 2.4.1 Elemental (Chemical) Compositional Analysis 39 2.4.2 Phase Composition and Microstructure 43 2.4.3 Molecular Composition and Chemical Bonding 45 2.4.4 Surface Morphology 49 2.4.5 Adsorption - Gases and Liquids 53 2.4.6 Mechanical and Thermal Properties of Surfaces 53 2.4.7 Surface Energy and Surface Tension 54 2.4.8 Acidic and Basic Properties of Surfaces 56 2.5 Bulk Properties 56 2.5.1 Outgassing 57 2.5.2 Outdiffusion 57 2.6 Modification of Substrate Surfaces 57 2.6.1 Surface Morphology 57 2.6.2 Surface Hardness 62 2.6.3 Strengthening of Surfaces 64 2.6.4 Surface Composition 65 2.6.5 Surface "Activation" ("Functionalization") 68 2.6.6 Surface "Sensitization" 71 2.7 Summary 71 Chapter 3: The "Good" Vacuum (Low Pressure) Processing Environment 73 3.1 Introduction 73 3.2 Gases and Vapors 73 3.2.1 Gas Pressure and Partial Pressure 74 3.2.2 Molecular Motion 79 3.2.3 Gas Flow 80 3.2.4 Ideal Gas Law 82 3.2.5 Vapor Pressure and Condensation 83 3.3 Gas-surface Interactions 84 3.3.1 Residence Time 84 3.3.2 Chemical Interactions 86 3.4 Vacuum Environment 87 3.4.1 Origin of Gases and Vapors 87 3.5 Vacuum Processing Systems 95 3.5.1 System Design Considerations and "Trade-Offs" 96 3.5.2 Processing Chamber Configurations 97

Contents 3.5.3 Equilibrium Conductance 100 3.5.4 Pumping Speed and Mass Throughput 102 3.5.5 Fixturing and Tooling 103 3.5.6 Feedthroughs and Accessories 106 3.5.7 Liners and Shields 107 3.5.8 Fail-Safe Designs 107 3.6 Vacuum pumping 110 3.6.1 Mechanical Pumps Ill 3.6.2 Momentum Transfer Pumps 113 3.6.3 Capture Pumps 116 3.6.4 Hybrid Pumps 120 3.7 Vacuum- and Plasma-Compatible Materials 120 3.7.1 Metals 121 3.7.2 Ceramic and Glass Materials 126 3.7.3 Polymers 127 3.8 Assembly 127 3.8.1 Permanent Joining 127 3.8.2 Non-Permanent Joining 128 3.8.3 Lubricants for Vacuum Application 130 3.8.4 Heating and Cooling in Vacuums 131 3.9 Evaluating Vacuum System Performance 134 3.9.1 System Records 134 3.10 Purchasing a Vacuum System for PVD Processing 135 3.11 Cleaning of Vacuum Surfaces 137 3.11.1 Stripping 137 3.11.2 Cleaning 140 3.11.3 In Situ "Conditioning" of Vacuum Surfaces 140 3.12 System-related Contamination 141 3.12.1 Particulate Contamination 141 3.12.2 Vapor Contamination 142 3.12.3 Gaseous Contamination 143 3.12.4 Changes with Use 143 3.13 Process-related Contamination 143 3.14 Safety Aspects of Vacuum Technology 144 3.15 Summary 144 Chapter 4: The Sub-Atmospheric Processing Environment 147 4.1 Introduction 147 4.2 Pressure Monitoring and Control 147 4.3 Mass Flow Meters (MFMs) and Mass Flow Controllers (MFCs) 148 4.3.1 Liquid Precursors 150 4.4 Geometry of the Pumping Manifold 150 4.4.1 Pumps 151

viii Contents 4.5 Conduction 151 4.5.1 Downstream Flow Control (Throttling) 151 4.5.2 Transit Conductance 152 4.6 Distribution Manifolds for Gas Flow Uniformity 152 4.6.1 Changing Gas Cylinders 153 4.6.2 Effluent Removal 154 4.8 Conclusion 156 Chapter 5: The Low Pressure Plasma Processing Environment 157 5.1 Introduction 157 5.2 The Plasma 159 5.2.1 Plasma Chemistry 159 5.2.2 Plasma Properties and Regions 164 5.3 Plasma-surface Interactions 167 5.3.1 Sheath Potentials and Self-bias 167 5.3.2 Applied Bias Potentials 167 5.3.3 Particle Bombardment Effects 168 5.3.4 Gas Diffusion into Surfaces 168 5.4 Configurations for Generating Plasmas 168 5.4.1 Electron Sources 168 5.4.2 Electric and Magnetic Field Effects 169 5.4.3 Direct Current (dc) Plasma Discharges 171 5.4.4 Pulsed Power Plasmas 176 5.4.5 Radio Frequency (rf) Capacitively Coupled Diode Discharge Plasmas 178 5.4.6 Arc Plasmas 180 5.4.7 Laser-Induced Plasmas 180 5.5 Ion and Plasma Sources 181 5.5.1 Plasma Sources 181 5.5.2 Ion Sources (Ion Guns) 185 5.5.3 Electron Sources 185 5.6 Plasma Processing Systems 186 5.6.1 Electrodes 187 5.6.2 Corrosion 187 5.6.3 Pumping Plasma Systems 188 5.7 Plasma-related Contamination 188 5.7.1 Desorbed Contamination 188 5.7.2 Sputtered Contamination 188 5.7.3 Arcing 189 5.7.4 Vapor Phase Nucleation 189 5.7.5 Cleaning Plasma Processing Systems 189 5.8 Some Safety Aspects of Plasma Processing 190 5.9 Summary 190

Contents ix Chapter 6: Vacuum Evaporation and Vacuum Deposition 795 6.1 Introduction 195 6.2 Thermal Vaporization 195 6.2.1 Vaporization of Elements 195 6.2.2 Vaporization of Alloys and Mixtures 200 6.2.3 Vaporization of Compounds 202 6.2.4 Polymer Evaporation 202 6.3 Thermal Vaporization Sources 203 6.3.1 Single Charge Sources 203 6.3.2 Replenishing (Feeding) Sources 211 6.3.3 Baffle Sources 211 6.3.4 Beam and Confined Vapor Sources 212 6.3.5 Flash Evaporation 212 6.3.6 Radiant Heating 213 6.4 Transport of Vaporized Material 213 6.4.1 Masks 213 6.4.2 Post-Vaporization Ionization 214 6.4.3 Gas Scattering 214 6.5 Condensation of Vaporized Material 214 6.5.1 Condensation Energy 214 6.5.2 Deposition of Alloys and Mixtures 215 6.5.3 Deposition of Compounds from Compound Source Materials 217 6.5.4 Some Properties of Vacuum-Deposited Thin Films 218 6.6 Materials for Evaporation 218 6.6.1 Purity and Packaging 218 6.6.2 Handling of Source Materials 218 6.7 Vacuum Deposition Configurations 219 6.7.1 Deposition Chambers 219 6.7.2 Fixtures and Tooling 220 6.7.3 Shutters 221 6.7.4 Substrate Heating and Cooling 221 6.7.5 Liners and Shields 222 6.7.6 In Situ Cleaning 222 6.7.7 Getter Pumping Configurations 222 6.8 Process Monitoring and Control 222 6.8.1 Substrate Temperature Monitoring 223 6.8.2 Deposition Monitors - Rate and Total Mass 223 6.8.3 Vaporization Source Temperature Monitoring 225 6.8.4 In Situ Film Property Monitoring 225 6.9 Contamination from the Processing 225 6.9.1 Contamination from the Vaporization Source 225 6.9.2 Contamination from the Deposition System 227

x Contents 6.9.3 Contamination from Substrates 227 6.9.4 Contamination from Deposited Film Material 227 6.10 Advantages and Disadvantages of Vacuum Deposition 227 6.11 Some Applications of Vacuum Deposition 228 6.11.1 Freestanding Structures 229 6.11.2 Graded Composition Structures 229 6.11.3 Multilayer Structures 229 6.11.4 Molecular Beam Epitaxy (MBE) 229 6.12 Gas Evaporation and Ultrafine (Nano) Particles 230 6.13 Other Processes 231 6.13.1 Reactive Evaporation and Activated Reactive Evaporation (ARE) 231 6.13.2 Jet Vapor Deposition Process 231 6.13.3 Field Evaporation 232 6.14 Summary 232 Chapter 7: Physical Sputtering and Sputter Deposition (Sputtering) 237 7.1 Introduction 237 7.2 Physical Sputtering 238 7.2.1 Bombardment Effects on Surfaces 239 7.2.2 Sputtering Yields 242 7.2.3 Sputtering of Alloys and Mixtures 244 7.2.4 Sputtering Compounds 244 7.2.5 Distribution of Sputtered Flux 245 7.3 Sputtering Configurations 246 7.3.1 Cold Cathode Direct Current (dc) Diode (Non-magnetron) Sputtering 247 7.3.2 AC (Including Mid-frequency) Sputtering 248 7.3.3 Radio Frequency (rf) Sputtering 248 7.3.4 Direct Current (dc) Magnetron Sputtering 249 7.3.5 Pulsed Power Magnetron Sputtering 251 7.3.6 Dual (Redundant) "Anode" Sputtering 252 7.3.7 Ion and Plasma Beam Sputtering 253 7.4 Transport of the Sputter-vaporized Species 253 7.4.1 Thermalization 253 7.4.2 Scattering 254 7.4.3 Collimation 254 7.4.4 Post-vaporization Ionization 254 7.4.5 Gas Flow Sputtering 254 7.5 Condensation of Sputtered Species 255 7.5.1 Elemental and Alloy Deposition 255 7.5.2 Reactive Sputter Deposition 256 7.5.3 Deposition of Composite Films 260 7.5.4 Some Properties of Sputter-Deposited Thin Films 260

Contents 7.6 Sputter Deposition Geometries 261 7.6.1 Fixturing 261 7.6.2 Target Configurations 263 7.6.3 Ion and Plasma Sources 264 7.6.4 Plasma Activation Using Auxiliary Plasmas 265 7.7 Targets and Target Materials 265 7.7.1 Target Configurations 265 7.7.2 Target Materials 266 7.7.3 Target Cooling, Backing Plates, and Bonding 268 7.7.4 Target Shielding 268 7.7.5 Target Specifications 269 7.7.6 Target Surface Changes with Use 269 7.7.7 Target Conditioning (Pre-Sputtering) 270 7.7.8 Target Power Supplies 270 7.8 Process Monitoring and Control 271 7.8.1 Sputtering System 271 7.8.2 Pressure 272 7.8.3 Gas Composition 272 7.8.4 Gas Flow 273 7.8.5 Target Power and Voltage 273 7.8.6 Plasma Properties 273 7.8.7 Substrate Temperature 273 7.8.8 Sputter Deposition Rate Monitoring 274 7.9 Contamination Due to Sputtering 275 7.9.1 Contamination from Desorption 275 7.9.2 Target-Related Contamination 275 7.9.3 Contamination from Arcing 275 7.9.4 Contamination from Wear Particles 275 7.9.5 Vapor Phase Nucleation 276 7.9.6 Contamination from Processing Gases 276 7.9.7 Contamination from Deposited Film Material 276 7.10 Advantages and Disadvantages of Sputter Deposition 277 7.11 Some Applications of Sputter Deposition 278 7.12 Summary 279 Chapter 8: Arc Vapor Deposition 287 8.1 Introduction 287 8.2 Arcs 287 8.2.1 Vacuum Arcs 287 8.2.2 Gaseous Arcs 289 8.2.3 Anodic Arcs 290 8.2.4 "Macros" 291 8.2.5 Arc Plasma Chemistry 292 8.2.6 Post Vaporization Ionization 292

xii Contents 8.3 Arc Source Configurations 292 8.3.1 Cathodic Arc Sources 292 8.3.2 Anodic Arc Sources 295 8.4 Reactive Arc Deposition 295 8.5 Arc Materials 295 8.6 Arc Vapor Deposition System 296 8.6.1 Arc Source Placement 296 8.6.2 Fixtures 296 8.6.3 Power Supplies 296 8.7 Process Monitoring and Control 296 8.8 Contamination Due to Arc Vaporization 297 8.9 Advantages and Disadvantages of Arc Vapor Deposition 297 8.9.1 Advantages 297 8.9.2 Disadvantages 297 8.10 Some Applications of Arc Vapor Deposition 297 8.11 Summary 298 Chapter 9: Ion Plating and Ion Beam-Assisted Deposition 307 9.1 Introduction 301 9.2 Stages of Ion Plating 304 9.2.1 Surface Preparation (In Situ) 304 9.2.2 Nucleation 305 9.2.3 Interface Formation 306 9.2.4 Film Growth 306 9.3 Sources of Depositing and Reacting Species 308 9.3.1 Thermal Vaporization 308 9.3.2 Physical Sputtering 309 9.3.3 Arc Vaporization 309 9.3.4 Chemical Vapor Precursor Species 310 9.3.5 Laser-Induced Vaporization 310 9.3.6 Gaseous Species 310 9.3.7 Film Ions (Self-Ions) 310 9.4 Sources of Energetic Bombarding Species 311 9.4.1 Bombardment from Gaseous Plasmas 311 9.4.2 Bombardment from Gaseous Arcs 312 9.4.3 Bombardment by High Energy Neutrals 312 9.4.4 Gaseous Ion and Plasma Sources (Guns) 313 9.4.5 Film Ion Sources 313 9.5 Sources of Accelerating Potential 314 9.5.1 Applied Bias Potential 314 9.5.2 Plasma Bias Potentials 315 9.5.3 Self-Bias Potential 316

Contents 9.6 Some Plasma-Based Ion Plating Configurations 317 9.6.1 Plasma and Bombardment Uniformity 317 9.6.2 Fixtures 317 9.7 Ion Beam-Assisted Deposition (IBAD) 319 9.8 Process Monitoring and Control 320 9.8.1 Substrate Temperature 320 9.8.2 Gas Composition and Mass Flow 320 9.8.3 Plasma Parameters 321 9.8.4 Deposition Rate 321 9.9 Contamination in the Ion Plating Process 321 9.9.1 Plasma Desorption and Activation 321 9.9.2 Vapor Phase Nucleation 322 9.9.3 Flaking 322 9.9.4 Arcing 322 9.9.5 Gas and Vapor Adsorption and Absorption 323 9.10 Advantages and Disadvantages of Ion Plating 323 9.11 Some Applications of Ion Plating 324 9.11.1 Plasma-Based Ion Plating 324 9.11.2 Vacuum-Based Ion Plating (IBAD) 325 9.12 Summary 325 Chapter 10: Atomistic Film Growth and Some Growth-Related Film Properties 333 10.1 Introduction 333 10.2 Condensation and Nucleation 337 10.2.1 Surface Mobility 337 10.2.2 Nucleation 337 10.2.3 Growth of Nuclei 342 10.2.4 Condensation Energy 344 10.3 Interface Formation 345 10.3.1 Abrupt Interface 345 10.3.2 Diffusion Interface 347 10.3.3 Compound Interface 348 10.3.4 Pseudodiffusion ("Graded" or "Blended") Interface 349 10.3.5 Modification of Interfaces 350 10.3.6 Characterization of Interfaces and Interfacial Material 351 10.4 Film Growth 352 10.4.1 Columnar Growth Morphology 353 10.4.2 Substrate Surface Morphology Effects on Film Growth 357 10.4.3 Modification of Film Growth 359 10.4.4 Lattice Defects and Voids 363 10.4.5 Film Density 363 10.4.6 Residual Film Stress 364

xiv Contents 10.4.7 Crystallographic Orientation 366 10.4.8 Gas Incorporation 368 10.5 Reactive and Quasi-Reactive Deposition of Films of Compound Materials 368 10.5.1 Chemical Reactions 369 10.5.2 Plasma Activation 372 10.5.3 Bombardment Effects on Chemical Reactions 372 10.5.4 Getter Pumping During Reactive Deposition 373 10.5.5 Particulate Formation 373 10.6 Post-Deposition Processing and Changes 373 10.6.1 Topcoats 374 10.6.2 Chemical and Electrochemical Treatments 375 10.6.3 Mechanical Treatments 376 10.6.4 Thermal Treatments 377 10.6.5 Ion Bombardment 378 10.6.6 Post-Deposition Changes 378 10.7 Deposition of Unique Materials and Structures 381 10.7.1 Metallization 381 10.7.2 Transparent Electrical Conductors 382 10.7.3 Low Emissivity (Low-E) Coatings 383 10.7.4 Permeation and Diffusion Barrier Layers 384 10.7.5 Porous Films 384 10.7.6 Composite (Two-Phase) Films 385 10.7.7 Intermetallic Films 386 10.7.8 Diamond and Diamond-Like Carbon (DLC) Films 386 10.7.9 Hard Coatings 387 10.8 Summary 390 Chapter 11: Film Characterization and Some Basic Film Properties 399 11.1 Introduction 399 11.2 Objectives of Characterization 400 11.3 Types of Characterization 400 11.3.1 Precision and Accuracy 401 11.3.2 Absolute Characterization 402 11.3.3 Relative Characterization 402 11.3.4 Functional Characterization 402 11.3.5 Behavioral Characterization 402 11.3.6 Sampling 403 11.4 Stages and Degree of Characterization 403 11.4.1 In Situ Characterization 403 11.4.2 First Check 404 11.4.3 Rapid Check 404 11.4.4 Post-Deposition Behavior 405 11.4.5 Extensive Check 406

Contents 11.4.6 Functional Characterization 406 11.4.7 Stability Characterization 406 11.4.8 Failure Analysis 407 11.4.9 Specification of Characterization Techniques 407 11.5 Some Film Properties 407 11.5.1 Residual Film Stress 407 11.5.2 Thickness 411 11.5.3 Density 413 11.5.4 Porosity, Microporosity, and Voids 413 11.5.5 Optical Properties 415 11.5.6 Mechanical Properties 419 11.5.7 Electrical Properties 421 11.5.8 Chemical Stability 423 11.5.9 Barrier Properties 424 11.5.10 Elemental Composition 425 11.5.11 Crystallography and Texture 431 11.5.12 Surface, Bulk, and Interface Morphology 431 11.5.13 Incorporated Gas 431 11.6 Summary 432 Chapter 12: Adhesion and Deadhesion 439 12.1 Introduction 439 12.2 Origin of Adhesion and Adhesion Failure (Deadhesion) 439 12.2.1 Chemical Bonding 439 12.2.2 Mechanical Bonding 440 12.2.3 Stress, Deformation, and Failure 440 12.2.4 Fracture and Fracture Toughness 441 12.2.5 Liquid Adhesion 442 12.3 Adhesion of Atomistically Deposited Inorganic Films 444 12.3.1 Condensation and Nucleation 444 12.3.2 Types of Interface 444 12.3.3 Film Properties that Affect Adhesion 446 12.3.4 Substrate Properties that Affect Adhesion 447 12.3.5 Post-Deposition Changes that Can Improve Adhesion 448 12.3.6 Post-Deposition Processing to Improve Adhesion Ion Implantation 448 12.3.7 Deliberately Non-Adherent Interfaces 449 12.4 Adhesion Failure (Deadhesion) 449 12.4.1 Spontaneous Failure 449 12.4.2 Externally Applied Mechanical Stress - Tensile and Shear 451 12.4.3 Chemical and Galvanic (Electrochemical) Corrosion 452 12.4.4 Diffusion to the Interface 453 12.4.5 Diffusion Away from the Interface 453 12.4.6 Reaction at the Interface 453

xvi Contents 12.4.7 Fatigue Processes 453 12.4.8 Subsequent Processing 454 12.4.9 Storage and In-Service 454 12.4.10 Local Adhesion Failure - Pinhole Formation 455 12.5 Adhesion Testing 455 12.5.1 Adhesion Test Program 455 12.5.2 Adhesion Tests 455 12.5.3 Non-Destructive Testing (Acceptance Testing) 460 12.5.4 Accelerated Testing 461 12.6 Designing for Good Adhesion 461 12.6.1 Film Materials, "Glue Layers," and Layered Structures 462 12.6.2 Special Interfacial Regions 463 12.6.3 Substrate Materials 463 12.7 Failure Analysis 465 12.8 Summary 466 Chapter 13: Cleaning 475 13.1 Introduction 475 13.2 Gross Cleaning 477 13.2.1 Stripping 477 13.2.2 Abrasive Cleaning 477 13.2.3 Chemical Etching 479 13.2.4 Electrocleaning 481 13.2.5 Fluxing 481 13.2.6 Deburring 481 13.3 Specific Cleaning 482 13.3.1 Solvent Cleaning 482 13.3.2 Aqueous Cleaning - Saponifiers, Soaps, and Detergents 487 13.3.3 Solution Additives 488 13.3.4 Reactive Cleaning 489 13.3.5 Reactive Plasma Cleaning and Etching 493 13.4 Application of Fluids 496 13.4.1 Soaking 496 13.4.2 Agitation 497 13.4.3 Vapor Condensation 497 13.4.4 Spraying 498 13.4.5 Ultrasonic Cleaning 498 13.4.6 Megasonic Cleaning 501 13.4.7 Wipeclean 502 13.5 Removal of Particulate Contamination 502 13.5.1 Blow-Off 502 13.5.2 Mechanical Disturbance 502

Contents 13.5.3 Fluid Spraying 503 13.5.4 Ultrasonic and Megasonic Cleaning 503 13.5.5 Flow-Off 503 13.5.6 Contact Cleaning 503 13.6 Rinsing 504 13.6.1 Hard and Soft Water 505 13.6.2 Pure and Ultrapure Water 505 13.6.3 Surface Tension 507 13.7 Drying, Outgassing, and Outdiffusion 508 13.7.1 Drying 508 13.7.2 Outgassing 510 13.7.3 Outdiffusion 511 13.8 Cleaning Lines 511 13.9 Handling and Storage/Transportation 513 13.9.1 Handling 514 13.9.2 Storage/Transportation 515 13.10 Evaluation and Monitoring of Cleaning 517 13.10.1 Behavior and Appearance 517 13.10.2 Chemical Analysis 518 13.10.3 Particle Detection 520 13.11 In Situ Cleaning 520 13.11.1 Plasma Cleaning 521 13.11.2 Sputter Cleaning 523 13.11.3 Laser Cleaning 524 13.11.4 Photodesorption 524 13.11.5 Electron Desorption 524 13.12 Contamination of the Film Surface 525 13.13 Safety 525 13.14 Summary 526 13.14.1 Cleaning Metals 526 13.14.2 Cleaning Glasses and Ceramics 526 13.14.3 Cleaning Polymers 526 Chapter 14: The External Processing Environment 529 14.1 Introduction 529 14.2 Reduction of Contamination 529 14.2.1 Elimination of Avoidable Contamination 530 14.2.2 Static Charge 531 14.3 Materials 532 14.3.1 Cloth, Paper, Foils, etc 532 14.3.2 Containers, Brushes, etc 533 14.3.3 Chemicals 534 14.3.4 Processing Gases 534

xviii Contents 14.4 Body Coverings 536 14.4.1 Gloves 536 14.4.2 Coats and Coveralls 538 14.4.3 Head and Face Coverings 538 14.4.4 Shoe Coverings 538 14.4.5 Gowning Area 538 14.4.6 Personal Hygiene 539 14.5 Processing Areas 539 14.5.1 Mechanical Filtration 540 14.5.2 Electronic and Electrostatic Filters 540 14.5.3 Humidity Control 541 14.5.4 Floor and Wall Coverings 541 14.5.5 Cleanrooms 541 14.5.6 Soft Wall Clean Areas 542 14.5.7 Cleanbenches 542 14.5.8 Ionizers 542 14.5.9 Particle Count Measurement 543 14.5.10 Vapor Detection 543 14.5.11 Reactive Gas Control 543 14.5.12 Microenvironments 543 14.5.13 Personnel Training 544 14.6 Summary 544 Appendix 545 Glossary 553 Index 735