Preface to First Edition ...................................... xix
Preface to Second Edition ..................................... xxi
Acknowledgements ............................................ xxiii
Acronyms ...................................................... xxv
Biography ..................................................... 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
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
3.5.1 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 .................................. 111
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 ........ 747
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
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
Chapter 6: Vacuum Evaporation and Vacuum Deposition .......... 195
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
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
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 Row ........................................... 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
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 ....... 301
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
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
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
11.4.1 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
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 Testings ........................................ 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
13.5.3 Fluid Spraying .................................... 503
13.5.4 Ultrasonic and Megasonic Cleaning ................. 503
13.5.5 Row-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
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
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