Reliability Wearout Mechanisms in Advanced CMOS Technologies (IEEE Press Series on Microelectronic Systems)

RELIABILITY WEAROUT MECHANISMS IN ADVANCED CMOS TECHNOLOGIES......Page 4
CONTENTS......Page 8
Preface......Page 16
1.1 Book Philosophy......Page 20
1.2.1 Reliability Purpose......Page 21
1.2.2 Accelerated Life......Page 22
1.2.3 Accelerating Condition......Page 27
1.3.1 Parametric or Deterministic Mechanisms......Page 28
1.3.2 Structural Mechanisms......Page 30
1.3.3 Statistical Mechanisms......Page 31
1.3.4 Infant Defects......Page 33
1.3.5 Operating Life Defects......Page 34
1.4.2 Assumptions......Page 35
1.4.3 Sampling and Variability......Page 37
1.4.4 Criteria, Censoring, and Plotting Points......Page 41
1.4.5 Definitions (Normal)......Page 44
1.4.6 Exponential Distribution......Page 57
1.4.7 Smallest Extreme Value and Weibull Distributions......Page 60
1.4.8 Lognormal Distribution......Page 64
1.4.9 Poisson Distribution......Page 68
1.5.1 Gamma and Chi-Square Distributions......Page 71
1.5.2 Student t Distribution......Page 72
1.6.1 Readouts Versus "Exact" Time-To-Fail......Page 73
1.6.2 Additional Types of Censoring......Page 74
1.6.3 Least-Squares Fit and Application......Page 75
1.6.4 Chi-Square Goodness of Fit Application......Page 83
1.6.6 Closure......Page 85
References......Page 86
2.1 Introduction......Page 90
2.1.1 Application and Fabrication of Silicon Dioxide-Based Dielectrics......Page 92
2.1.2 Failure Modes of Gate Oxide and Reliability Requirements......Page 95
2.1.3 Impact of Oxide Scaling......Page 100
2.2.1 Capacitance–Voltage Characteristics......Page 104
2.2.2 Carrier Tunnelling and Injection Mechanisms in MOS Structures......Page 114
2.2.3 Oxide Voltage (Field) and Electron Energy at Anode......Page 129
2.2.4 Determination of Oxide Thickness......Page 134
2.3.1 Measurement Methods......Page 143
2.3.2 Designs of Stress and Test Structures......Page 163
2.3.3 Physical Observations of Dielectric Breakdown......Page 167
2.3.4 Considerations for Oxide Breakdown Detection......Page 170
2.4.1 Weibull Function and Poisson Statistics......Page 173
2.4.2 Area Transformation......Page 179
2.4.3 Weibull Versus Lognormal Failure Distributions......Page 185
2.4.4 Estimation of Weibull Parameters......Page 187
2.4.5 Methods for Determination of the Weibull Shape Factor (Slope)......Page 196
2.4.6 Modeling Bi- or Multimodal Weibull Distributions......Page 197
2.5 Summary and Future Trends......Page 211
References......Page 212
3.1 Introduction......Page 228
3.2.1 Oxide Degradation......Page 229
3.2.2 The Role of Electric Field and Carrier Energy in the Degradation and Breakdown of Gate Oxides......Page 237
3.2.3 Percolation Model for the Breakdown Statistics......Page 241
3.2.4 Three-Dimensional Analytic Model for Oxide Breakdown Statistics......Page 242
3.2.5 Thickness Dependence of Oxide Breakdown......Page 245
3.3 Physical Models for Oxide Degradation and Breakdown......Page 250
3.3.1 The Thermochemical Model......Page 251
3.3.2 Hole-Induced Breakdown Models......Page 255
3.3.3 Anode Hydrogen Release Model......Page 268
3.4 Experimental Results of Oxide Breakdown......Page 278
3.4.1 Voltage Dependence......Page 279
3.4.2 Temperature Dependence......Page 291
3.4.3 Interrelationship of Voltage and Temperature Dependence......Page 295
3.4.4 Polarity Dependence......Page 299
3.4.5 Degradation and Breakdown Under AC Stress Conditions......Page 303
3.4.6 Gate Oxide Reliability Projection......Page 306
3.5 Post-Breakdown Phenomena......Page 314
3.5.1 Review of Post-Breakdown Experimental Observations......Page 315
3.5.2 Modeling the Post-Breakdown Statistics......Page 325
References......Page 333
4.1 Introduction......Page 350
4.2 Considerations on NBTI Stress Configurations......Page 352
4.3 Appropriate NBTI Stress Bias Dependence......Page 354
4.4 Nature of the NBTI Damage......Page 358
4.5 Impact of the NBTI Damage to Key pMOSFET Transistor Parameters......Page 360
4.5.1 Impact of the NBTI Damage to pMOSFET Physical Parameters......Page 361
4.5.2 Relation Between Key Physical and Electrical pMOSFET Parameters......Page 363
4.6 Physical Mechanisms Contributing to the NBTI Damage......Page 369
4.6.1 Interface Traps Generation......Page 370
4.6.2 Positive Charge Defects Generation/Activation......Page 374
4.7.1 pMOSFET NBTI: Worst MOSFET Bias Temperature Condition......Page 382
4.7.2 Role of Cold Holes......Page 385
4.7.3 Dependence on Gate Oxide Electric Field......Page 387
4.7.4 Dependence on Stress Temperature......Page 391
4.7.5 Time Evolution......Page 394
4.7.6 Recovery Phenomena......Page 397
4.7.7 Impact of NBTI Recovery to NBTI Stressing/Testing Methodologies......Page 402
4.7.8 Dynamic NBTI......Page 409
4.8 N(it) Generation by Reaction–Diffusion (R–D) Processes......Page 414
4.8.1 Modeling of N(it) Generation by Reaction–Diffusion Processes......Page 416
4.8.2 R–D Kinetics Controlled By an Arrhenius Diffusion Process......Page 420
4.8.3 R–D Kinetics Controlled By a Dispersive Diffusion in SiO(2)......Page 426
4.8.4 N(it) Repassivation Phase......Page 428
4.8.5 Dynamic NBTI......Page 430
4.9 Hole Trapping Modeling......Page 431
4.10.1 Hydrogen Species......Page 436
4.10.2 Nitrogen......Page 438
4.10.3 Fluorine......Page 441
4.10.4 Boron......Page 443
4.10.5 NBTI Sensitivity to BEOL Charging......Page 445
4.11 NBTI Dependence on Area Scaling......Page 447
4.12 Overview of Key NBTI Features......Page 450
References......Page 453
5.1 Introduction......Page 460
5.2 Hot Carriers: Physical Generation and Injection Mechanisms......Page 462
5.2.1 Electric Field in a MOSFET Pinch-Off Region......Page 463
5.2.2 Lateral Electric Field in the Pinch-Off Region of an LDD MOSFET......Page 469
5.2.3 Vertical Electric Field in the Pinched-Off Channel Region......Page 472
5.2.4 High Field-Induced Carrier Heating and the Carrier Energy Distribution Function......Page 473
5.2.5 Impact Ionization Phenomena......Page 483
5.2.6 Primary Impact Ionization (1II) in a MOSFET in Saturation......Page 488
5.2.7 Channel Hot Carrier Injection Mechanisms......Page 491
5.2.8 Lucky Electron Model......Page 495
5.2.10 Secondary Impact Ionization (2II)......Page 500
5.2.11 Limits of the Lucky Electron Model......Page 504
5.2.12 The Energy-Driven Model......Page 505
5.2.13 Localized Self-Heating Effects......Page 508
5.3.1 Introduction......Page 510
5.3.2 Interface States Generation......Page 513
5.3.3 The Giant Isotope Effect......Page 517
5.4.1 I(d)–V(gs) Shifts......Page 518
5.4.2 Localization of Channel Hot Carrier Damage in the Drain Region......Page 524
5.4.3 CHC-induced Increase in Parasitic Drain Series Resistance......Page 525
5.5.1 Note About "Device Lifetime"......Page 527
5.5.2 Lucky Electron Model–Peak I(sx) CCHC......Page 528
5.5.3 The Electron-Effective Temperature Model......Page 529
5.5.4 Energy-Driven Model: nMOSFET CCHC......Page 530
5.5.5 Modeling of PFET Conducting Channel Hot Carrier......Page 532
References......Page 533
6.1.1 Overview......Page 536
6.1.2 Conceptual Basis......Page 538
6.2 Theory and Model......Page 543
6.2.1 Relating Time-to-Failure to Void Size......Page 549
6.2.2 Stress Contribution......Page 552
6.2.3 Accelerated Testing for Stress Voiding......Page 554
6.2.4 Alloying and Impurity Effects......Page 557
6.2.5 Relating Resistance Changes to Void Growth......Page 560
6.2.6 Factors that Complicate SV Data......Page 562
6.3 Role of the Overlying Dielectric......Page 565
6.4 Summary of Voiding in Al Metallizations......Page 568
6.5 Stress Voiding in Cu Interconnects......Page 569
6.5.1 Microstructure of Cu......Page 573
6.5.2 Role of Dielectrics in Cu Voiding......Page 574
6.5.3 Microstructural Effects......Page 575
6.5.4 Structural Influences......Page 577
6.5.5 Structures and Models for Cu Voiding......Page 579
6.6 Concluding Remarks......Page 581
References......Page 582
7.1 Introduction......Page 584
7.2 Metallization Failure......Page 585
7.3 Electromigration......Page 586
7.3.1 Single-Component Metallization......Page 590
7.3.2 Layered Metallizations......Page 593
7.3.3 Short-Length Effect......Page 597
7.3.4 Multilevel Metallizations......Page 599
7.3.5 Incubation Time......Page 603
7.3.6 Electromigration in Cu Lines......Page 605
7.3.7 Electromigration Testing......Page 607
7.4 General Approach to Electromigration Reliability......Page 608
7.4.1 Projection Methodology Statistical Considerations......Page 611
7.4.2 Normal Distribution......Page 613
7.4.3 Lognormal Distribution......Page 616
7.4.4 Bimodal Distributions......Page 622
7.4.5 Three-Parameter Lognormal Fit to a Single Distribution......Page 624
7.5.1 Self-Heating......Page 626
7.5.2 Wafer-Level Electromigration......Page 633
7.5.3 Indirect Joule Heating......Page 635
References......Page 636
Index......Page 638