Handbook of Silicon Based MEMS Materials & Technologies

Front matter......Page 1
Copyright......Page 4
Preface......Page 5
List of Contributors......Page 7
Towards Mass Volumes of MEMS Devices......Page 10
Automotive Applications Drive the Reliability and the Quality......Page 11
Leaps Towards a Generic Manufacturing Platform......Page 12
Towards Every Pocket......Page 13
Mobile Phones and Mobile Multimedia Computers......Page 17
Ubiquitous Sensing, Computing and Communication......Page 21
Future of MEMS Technologies......Page 23
Acknowledgements......Page 24
Properties of Silicon......Page 28
References......Page 41
The CZ Crystal-Growing Furnace......Page 43
Stages of Growth Process......Page 47
Issues of Crystal Growth......Page 50
Improved Thermal and Gas Flow Designs......Page 52
Heat Transfer......Page 53
Melt Convection......Page 54
Magnetic Fields......Page 58
Hot Recharging......Page 59
Further reading......Page 60
Dopants and Impurities......Page 61
Typical Impurity Concentrations......Page 63
Concentration of Dopants and Impurities in Axial Direction......Page 64
Resistivity......Page 66
Radial Variation of Impurities and Resistivity......Page 68
Thermal Donors......Page 71
Defects in Silicon Crystals......Page 72
Control of Vacancies, Interstitials, and the OISF Ring......Page 75
Conclusion......Page 77
References......Page 78
Oxygen in Solid Solution......Page 82
Precipitation of Oxygen......Page 83
Precipitate-Induced Defects......Page 87
Behavior of Oxygen in Basic Heat Treatment Procedures......Page 88
References......Page 91
Silicon Wafers: Preparation and Properties......Page 93
Ingot Cutting and Shaping......Page 94
ID Cutting......Page 95
Wafer Marking......Page 96
Edge Grinding......Page 98
Chemical Etching......Page 99
Polishing......Page 100
Clean Room Operations......Page 101
Standard Measurements of Polished Wafers......Page 102
Metal Concentration Measurements......Page 103
Sample Specifications of MEMS Wafers......Page 104
Standards of Silicon Wafers......Page 106
Silicon Epitaxy—The Basics......Page 111
The Epi-Poly Process......Page 116
Etch Stop Layers......Page 117
Epi on SOI Substrates......Page 118
Selective Epitaxy and Epitaxial Layer Overgrowth......Page 119
Metrology......Page 120
Commercially Available Epitaxy Systems......Page 123
Summary......Page 126
References......Page 127
Introduction......Page 129
Overview of SOI......Page 130
Silicon Wafer Parameters for Direct Bonding......Page 134
Fabrication of Thick-Film BSOI by Mechanical Grinding and Polishing......Page 137
BESOI Process......Page 150
Techniques Based on Thin-Film SOI and Silicon Epitaxy......Page 152
Conclusion......Page 156
References......Page 157
Growth Methods of Silicon Dioxide......Page 159
Structure and Properties of Silicon Dioxides......Page 166
Processing of Silicon Dioxides......Page 167
References......Page 169
Microscopic and Macroscopic Equations......Page 171
Computational Methods......Page 173
References......Page 176
Introduction......Page 177
Requirements for Modeling Micromachining......Page 178
Micromachining As a Front Propagation Problem......Page 179
Anisotropic Etching: Geometrical Simulators......Page 180
Anisotropic Etching: Atomistic Simulators......Page 182
A Survey of Etching Simulators......Page 192
References......Page 195
Basic Structural Properties of Crystalline Silicon......Page 198
Dislocations in Silicon......Page 206
Physical Mechanisms of Fracture in Silicon......Page 220
Physical Mechanisms of Fatigue of Silicon......Page 229
References......Page 233
Additional References......Page 238
Model System for a DynamicMicromechanical Device......Page 239
Electrical Equivalent Circuit......Page 241
Electrostatic Force......Page 243
Sensing of Motion......Page 246
Parasitic Capacitance......Page 247
Effect of Built-in Potentialon Capacitively Coupled MEMS Devices......Page 248
Further Effects of Electrostatic Nonlinearities from Applications Point of View......Page 249
RF-Properties......Page 252
References......Page 254
Optical Properties of Siliconand Related Materials......Page 256
Optical Properties of Silicon......Page 257
Optical Properties of Other Materials Commonly Used in Optical MEMS......Page 258
Geometrical Optics......Page 259
Scalar Wave Model......Page 260
Fourier Transform in Optics......Page 263
Electromagnetic Optics......Page 264
Numerical Modeling Methodsfor Optical MEMS......Page 266
Optical Modeling of ThinFilm Stacks......Page 267
Calculation of 2D Waveguide Modes......Page 269
Beam Propagation Method......Page 271
Finite Difference Time Domain Method......Page 272
Grating Diffraction......Page 273
References......Page 274
Introduction......Page 276
Damping Dominated by Gas Viscosity......Page 277
First-Order Frequency Dependencies......Page 288
Viscoacoustic Models......Page 291
Simulation Tools......Page 292
References......Page 293
On MEMS Measurements......Page 297
Variation and Mapping......Page 298
MEMS Measurement Challenges......Page 300
References......Page 301
Wafer Shape......Page 302
Resistivity......Page 304
Thickness of Thin Films......Page 308
References......Page 311
Camera-Based Measurements......Page 312
References......Page 317
Introduction......Page 318
MEMS residual stress characterization techniques......Page 319
Perspective and Conclusion......Page 327
References......Page 328
Solid Mechanics......Page 330
Tensile Test Method......Page 331
Blister Test Method......Page 332
Summary and Outlook......Page 333
References......Page 334
FIB for Direct Milling and Deposition of Structures......Page 335
DualBeam Applications of FA and Characterization of MEMS Devices......Page 336
Reference......Page 337
Measuring Oxygen in Silicon......Page 338
Measuring Bulk Microdefects......Page 339
References......Page 341
Lithography Considerations Before Wafer Processing......Page 342
Wafers in Lithography Process......Page 344
Processing After Lithography......Page 350
Thick Photoresist Lithography......Page 351
References......Page 356
Etch Chemistries......Page 358
Equipment......Page 359
DRIE Processes......Page 362
DRIE Advanced Issues and Challenges......Page 369
DRIE Applications......Page 374
Post-DRIE Etch Treatments......Page 378
Choosing between Wet and Dry Etching......Page 379
References......Page 380
Basic Description of Anisotropic Etching: Faceting......Page 384
Beyond Faceting: Atomistic Phenomena......Page 387
Beyond Atomistics: Electrochemistry......Page 391
Typical Surface Morphologies (I. Zubel and M.A. Gosálvez)......Page 393
Effects from Silicon Wafer Features (E. Viinikka)......Page 397
Convex Corner Undercutting......Page 399
Examples of Wet Etching......Page 400
Popular Wet Etchants......Page 402
Temperature Dependence of the Etch Rate......Page 406
Concentration Dependence of the Etch Rate......Page 408
Converting Between Different Measures of Concentration......Page 411
References......Page 413
PS Sacrificial Layer Technologies......Page 417
PS Fabrication Technology......Page 418
Microscopic Processes Underlying PS Formation......Page 420
Formation of Silicon Microstructures......Page 424
Application Examples......Page 432
Summary and Conclusions......Page 437
References......Page 438
Atomic Layer Deposition: An Introduction......Page 440
Operation Principles of ALD......Page 441
ALD Processes......Page 442
Characteristics of ALD Processes and Films......Page 444
ALD Reactors......Page 447
Applications for ALD in MEMS......Page 450
References......Page 452
Introduction......Page 454
Glassy/Amorphous Metals......Page 457
Properties of Metallic Glasses......Page 459
Microfabrication Ability of BMGs......Page 461
Nanoforming Ability of Glassy Metals (Below 100 nm)......Page 464
Applications of BMGs in MEMS......Page 467
Metallic Glass Thin Films: A Pathway to Integrated MEMS......Page 470
Micro/Nanofabrication Ability of Glassy Thin Films......Page 475
References......Page 478
Polycrystalline Silicon-Based Micromachining......Page 480
Metallic MEMS......Page 484
SOI-Wafer-Based Surface Micromachining......Page 487
References......Page 493
Introduction to Silicon Based BioMEMS Devices......Page 495
Silicon BioMEMS for Health Care......Page 496
Silicon BioMEMS for Biological Detection......Page 498
Conclusions and Future Research Areas......Page 501
References......Page 502
Encapsulation in Surface Micromachining......Page 505
Wafer Bonding Methods......Page 506
Via Technologies......Page 507
References......Page 508
Hydrophilic High-Temperature Wafer Bonding......Page 509
Hydrophobic High-Temperature Bonding of Silicon......Page 511
Low-Temperature Direct Bonding of Silicon......Page 512
Direct Bonding of CVD Oxides......Page 513
Direct Bonding of CVD Silicon......Page 514
References......Page 515
The Mechanism of the Anodic Bonding......Page 517
Bonding Parameters......Page 519
Bond Quality, Failure Modes and Characterization......Page 520
The Effect of the Anodic Bonding on the Flexible Micromachined Structures......Page 521
Bonding with Thin Films......Page 522
Conclusions......Page 523
References......Page 524
Glass Frit Materials......Page 525
Screen Printing......Page 526
Thermal Conditioning......Page 528
Bonding Process......Page 529
Physics of Bonding......Page 532
Characteristics......Page 533
Conductive Glass Frit Bonding......Page 534
Additional Reference......Page 535
Properties of Metallic Seal Bonds......Page 536
Metal Systems for Seal Bonding......Page 537
Soft Soldering......Page 538
Eutectic Bonding......Page 539
TLP Bonding......Page 540
Diffusion Bonding......Page 541
Metallic Seal Ring Design and Process Technology......Page 542
Process Guidance of Metallic Alloy Bonding......Page 543
References......Page 545
General Aspects, Requirements, and Limitations of CMOS-Compatible Wafer Bonding......Page 546
Anodic Bonding of CMOS-Processed Wafers......Page 548
CMOS Wafer Glass Frit Bonding......Page 550
Adhesive Bonding of CMOS Wafers......Page 552
References......Page 553
Testing Principle......Page 554
FEA......Page 555
Results......Page 556
References......Page 557
Wafer-Bonding Equipment......Page 558
Aligned Wafer-Bonding Requirements for MEMS Applications......Page 559
Wafer Aligners......Page 560
Wafer Bonders......Page 563
Aligned Wafer Bonding: Equipment Solutions for MEMS Manufacturing......Page 567
References......Page 571
Packaging Needs......Page 572
Technologies and Methods......Page 573
References......Page 576
References......Page 578
References......Page 587
Methods of Dicing......Page 602
Stealth Dicing......Page 604
Effects of Dicing......Page 605
References......Page 607
Hermeticity Requirements......Page 608
Hermeticity Tests......Page 609
Neon Ultra-Fine Leak Test......Page 611
Vacuum Lifetime Model......Page 613
References......Page 617
Appendix 1 - Common Abbreviations and Acronyms......Page 618
1 Nanoindentation Method......Page 624
2 Indentation in Silicon......Page 625
References......Page 628
B......Page 629
D......Page 630
H......Page 631
M......Page 632
P......Page 633
S......Page 634
T......Page 635
Z......Page 636