Single Event Effects in Aerospace

1. Introduction 1

1.1 Background 1

1.2 Analysis of Single Event Experiments 7

1.2.1 Analysis of Data Integrity and Initial Data Corrections 7

1.2.2 Analysis of Charge Collection Experiments 7

1.2.3 Analysis of Device Characteristics from Cross-Section Data 7

1.2.4 Analysis of Parametric Studies of Device Sensitivity 8

1.3 Modeling Space and Avionics See Rates 8

1.3.1 Modeling the Radiation Environment at the Device 8

1.3.2 Modeling the Charge Collection at the Device 9

1.3.3 Modeling the Electrical Characteristic and Circuit Sensitivity for Upset 9

1.4 Overview of this Book 10

1.5 Scope of this Book 11

2. Foundations of Single Event Analysis and Prediction 13

2.1 Overview of Single Particle Effects 13

2.2 Particle Energy Deposition 15

2.3 Single Event Environments 18

2.3.1 The Solar Wind and the Solar Cycle 19

2.3.2 The Magnetosphere Cosmic Ray and Trapped Particle Motion 22

2.3.3 Galactic Cosmic Rays 24

2.3.4 Protons Trapped by the Earth’s Magnetic Fields 42

2.3.5 Solar Events 46

2.3.6 Ionization in the Atmosphere 48

2.4 Charge Collection and Upset 58

2.5 Effective Let 60

2.6 Charge Collection Volume and the Rectangular Parallelepiped (RPP) 61

2.7 Upset Cross Section Curves 62

2.8 Critical Charge 62

2.8.1 Critical Charge and LET Threshold 63

2.8.2 Critical Charge of an Individual Transistor Two Transistors in a Cell 64

2.8.3 Critical Charge from Circuit Modeling Studies 65

2.8.4 Sensitivity Distribution Across the Device 65

2.8.5 Intracell Variation 66

2.8.6 Summary Discussion of Critical Charge 66

2.9 Upset Sensitivity and Feature Size 67

2.10 Cross-Section Concepts 67

2.10.1 Nuclear Physics Cross-Section Concepts 67

2.10.2 Single Event Cross-Section Concepts 72

3. Optimizing Heavy Ion Experiments for Analysis 77

3.1 Sample Heavy Ion Data 78

3.2 Test Requirements 78

3.3 Curve Parameters 80

3.4 Angular Steps 85

3.5 Stopping Data Accumulation When You Reach the Saturation Cross Section 86

3.6 Device Shadowing Effects 88

3.7 Choice of Ions 89

3.8 Determining the LET in the Device 91

3.9 Energy Loss Spread 94

3.10 Data Requirements 95

3.10.1 Desired Precision 95

3.10.2 Desired Accuracy 97

3.11 Experimental Statistics and Uncertainties 97

3.12 Effect of Dual Thresholds 98

3.13 Fitting Cross-Section Data 99

3.14 Other Sources of Error and Uncertainties 101

4. Optimizing Proton Testing 103

4.1 Monitoring the Beam Intensity and Uniformity 103

4.2 Total Dose Limitations on Testing 104

4.3 Shape of the Cross-Section Curve 105

5. Data Qualification and Interpretation 111

5.1 Data Characteristics 111

5.1.1 Illegitimate Systematic and Random Errors 111

5.1.2 Inherent Random Errors 113

5.1.3 Fractional Standard Deviation of Your Data 117

5.1.4 Rejection of Data 119

5.2 Approaches to Problem Data 121

5.2.1 Examination of Systematic Errors 121

5.2.2 An Example of Voltage Variation 134

5.2.3 Data Inconsistent with LET 135

5.2.4 Beam Contamination 135

5.2.5 No Event Observed 138

5.2.6 Sloppy or Wrong Fits to the Data 139

5.2.7 Experiment Monitoring and Planning 141

5.3 Interpretation of Heavy Ion Experiments 142

5.3.1 Modification of Effective LET by the Funnel 142

5.3.2 Effects of True RPP Shape 144

5.3.3 Fitting Data to Determine Depth and Funnel Length 149

5.3.4 Deep Device Structures 152

5.3.5 Cross-Section Curves on Rotated RPP Structures 156

5.3.6 Charge Gain Effects on Cross Section 157

5.4 Possible Problems with Least Square Fitting Using the Weibull Function 158

5.4.1 Multiple Good Fits 158

5.4.2 Reason for Inconsistent Weibull Fitting 162

6. Analysis of Various Types of SEU Data 165

6.1 Critical Charge 165

6.2 Depth and Critical Charge 166

6.3 Charge Collection Mechanisms 168

6.3.1 Drift Process and Funneling 168

6.3.2 Diffusion Process 168

6.3.3 Plasma Wire Effect 169

6.3.4 ALPHEN (Alpha-Particle–Source–Drain Penetration Effect) 169

6.3.5 Bipolar Transistor Effect 169

6.3.6 Recombination Effects 169

6.4 Charge Collection and the Cross-Section Curve 170

6.4.1 CMOS 170

6.4.2 Hardened CMOS 171

6.4.3 Bipolar Devices 171

6.4.4 CMOS-SOI 172

6.4.5 NMOS–Depletion Load 172

6.4.6 NMOS–Resistive Load 172

6.4.7 GaAs HFETs 173

6.4.8 GaAs C-Higfet 173

6.4.9 VLSI Process Variation 173

6.5 Efficacy (Variation of SEU Sensitivity within a Cell) 174

6.5.1 Cross-Section and Efficacy Curves 174

6.5.2 SEU Efficacy as a Function of Area 176

6.5.3 Efficacy and SEU Sensitivity Derived from a Pulsed Laser SEU Experiment 178

6.6 Mixed-Mode Simulations 185

6.6.1 Warren Approach 186

6.6.2 Dodd Approach 188

6.6.3 Hirose Approach 189

6.6.4 Simplified Approach of Fulkerson 189

6.6.5 The Imax F (Tmax) Approach 190

6.6.6 Circuit Level Simulation to Upset Rate Calculations 194

6.6.7 Multiple Upset Regions 194

6.6.8 Efficacy and SEU Threshold 195

6.6.9 From Efficacy to Upset Rates 197

6.7 Parametric Studies of Device Sensitivity 198

6.7.1 Data Display and Fitting 198

6.7.2 Device Parameters and SEU Sensitivity 202

6.8 Influence of Ion Species and Energy 215

6.9 Device Geometry and the Limiting Cross Section 218

6.9.1 Bulk CMOS 218

6.9.2 CMOS/SOI 218

6.9.3 SRAMs 219

6.10 Track Size Effects 220

6.11 Cross-Section Curves and the Charge Collection Processes 221

6.11.1 Efficacy Curves and the Charge-Collection Process 222

6.11.2 Inverse LET Plots and Diffusion 225

6.12 Single Event Multiple-Bit Upset 226

6.12.1 Strictly Geometrical MBUs 227

6.12.2 Proton Induced Multibit Upsets 230

6.12.3 Dual Hits for Single-Bit Upset 231

6.12.4 MBU Due to Diffusion in DRAMs 231

6.12.5 Hits to Adjacent Sensitive Regions 236

6.12.6 Multibit Upset in FPGAs 236

6.12.7 Calculation of Upset Rate for Diffusion MBUs 237

6.12.8 Geometrical MBE Rates in EDAC Words 238

6.12.9 Statistical MBE Rates in the Space

Environment 240

6.12.10Impact of Geometrical Errors on System Performance 243

6.12.11Statistical MBUs in a Test Environment 246

6.13 SEU in Logic Systems 246

6.14 Transient Pulses 249

7. Cosmic Ray Single Event Rate Calculations 251

7.1 Introduction to Rate Prediction Methods 252

7.2 The RPP Approach to Heavy Ion Upset Rates 252

7.3 The Integral RPP Approach 260

7.4 Shape of the Cross-Section Curve 264

7.4.1 The Weibull Distribution 264

7.4.2 Lognormal Distributions 266

7.4.3 Exponential Distributions 267

7.5 Assumptions Behind the RPP and IRPP Methods 270

7.5.1 Device Interaction Models 270

7.5.2 Critical Charge 270

7.5.3 Mathematical Basis of Rate Equations 271

7.5.4 Chord Length Models 274

7.5.5 Bradford Formulation 276

7.5.6 Pickel Formulation 279

7.5.7 Adams Formulation 280

7.5.8 Formulation of Integral RPP Approach 282

7.5.9 HICCUP Model 284

7.5.10 Requirements for Use of IRPP 285

7.6 Effective Flux Approach 285

7.7 Upper Bound Approaches 287

7.8 Figure of Merit Upset Rate Equations 288

7.9 Generalized Figure of Merit 290

7.9.1 Correlation of the FOM with Geosynchronous Upset Rates 291

7.9.2 Determination of Device Parameters 294

7.9.3 Calculation of the Figure of Merit from Tabulated Parts Characteristics 295

7.9.4 Rate Coefficient Behind Shielding 298

7.10 The FOM and the LOG Normal Distribution 299

7.11 Monte Carlo Approaches 300

7.11.1 IBM Code 300

7.11.2 GEANT4 300

7.11.3 Neutron Induced 301

7.12 PRIVIT 302

7.13 Integral Flux Method 302

8. Proton Single Event Rate Calculations 305

8.1 Nuclear Reaction Analysis 306

8.1.1 Monte Carlo Calculations 310

8.1.2 Predictions of Proton Upset Cross Sections Based on Heavy Ion Data 311

8.2 Semiempirical Approaches and the Integral Cross-Section Calculation 313

8.3 Relationship of Proton and Heavy Ion Upsets 316

8.4 Correlation of the FOM with Proton Upset Cross Sections 317

8.5 Upsets Due to Rare High Energy Proton Reactions 318

8.6 Upset Due to Ionization by Stopping Protons Helium Ions and Iron Ions 320

9. Neutron Induced Upset 329

9.1 Neutron Upsets in Avionics 330

9.1.1 BGR Calculation 330

9.1.2 Integral Cross-Section Calculation 331

9.1.3 Figure of Merit Calculation 332

9.1.4 Upper Bound Approach 333

9.1.5 Exposure During Flights 334

9.2 Upsets at Ground Level 335

10. Upsets Produced by Heavy Ion Nuclear Reactions 337

10.1 Heavy Ion Nuclear Reactions 337

10.2 Upset Rate Calculations for Combined Ionization and Reactions 340

10.3 Heavy Nuclear Ion Reactions Summary 342

11. Samples of Heavy Ion Rate Prediction 345

11.1 Low Threshold Studies 345

11.2 Comparison of Upset Rates for Weibull and Lognormal Functions 347

11.3 Low Threshold–Medium Lc data 352

11.4 See Sensitivity and LET Thresholds 353

11.5 Choosing Area and Depth for Rate Calculations 360

11.5.1 SOI Devices 360

11.5.2 Inclusion of Funnel in CREME Calculation 361

11.6 Running CREME96 Type Codes 361

11.6.1 CREME96/FLUX 363

11.6.2 CREME96/TRANS 364

11.6.3 CREME96/LETSPEC 364

11.6.4 CREME96/HUP 365

11.6.5 CREME96 Results 366

11.7 CREME-MC and SPENVIS 367

11.8 Effect of Uncertainties in Cross Section on Upset Rates 368

12. Samples of Proton Rate Predictions 371

12.1 Trapped Protons 371

12.2 Correlation of the FOM with Proton Upset Rates 371

13. Combined Environments 375

13.1 Relative Proton and Cosmic Ray Upset Rates 375

13.2 Calculation of Combined Rates Using the Figure of Merit 375

13.3 Rate Coefficients for a Particular New Orbit 380

13.4 Rate Coefficients for Any Circular Orbit About the Earth 381

13.5 Ratio of Proton to Heavy Ion Upsets for Near Earth Circular Orbits 381

13.6 Single Events from Ground to Outer Space 383

14. Samples of Solar Events and Extreme Situations 389

15. Upset Rates in Neutral Particle Beam (NPB) Environments 395

15.1 Characteristics of NPB Weapons 395

15.2 Upsets in the NPB Beam 397

16. Predictions and Observations of SEU Rates in Space 401

16.1 Results of Space Observations 402

16.2 Environmental Uncertainties 413

16.3 Examination of Outliers 417

16.4 Possible Reasons for Poor Upset Rate Predictions 418

16.5 Constituents of a Good Rate Comparison Paper 420

16.5.1 Reports on Laboratory and Space Measurements 421

16.5.2 Analysis of Ground Measurements 422

16.5.3 Environment for Space Predictions 422

16.5.4 Upset Rate Calculations 423

16.5.5 Characteristics of Space Experiment and Data 424

16.6 Summary and Conclusions 425

16.7 Recent Comparisons 427

16.8 Comparisons with Events During Solar Activity 427

17. Limitations of the IRPP Approach 429

17.1 The IRPP and Deep Devices 429

17.2 The RPP When Two Hits are Required 430

17.3 The RPP Approaches Neglect Track Size 430

17.4 The IRPP Calculates Number of Events not Total Number of Upsets 431

17.5 The RPP Approaches Neglect Effects that Arise Outside the Sensitive Volume 431

17.6 The IRPP Approaches Assume that the Effect of Different

Particles with the Same LET is Equivalent 431

17.7 The IRPP Approaches Assume that the LET of the Particle is not Changing in the Sensitive Volume 432

17.8 The IRPP Approach Assumes that the Charge Collection Does Not Change with Device Orientation 433

17.9 The Status of Single Event Rate Analysis 433

Appendix A Useful Numbers 435

Appendix B Reference Equations 437

Appendix C Quick Estimates of Upset Rates Using the Figure of Merit 445

Appendix D Part Characteristics 448

Appendix E Sources of Device Data 452

References 455

Author Index 489

Subject Index 495