Design for Manufacturability and Statistical Design (eBook)

Contents 10
1 INTRODUCTION 14
1.1 RISE OF LAYOUT CONTEXT DEPENDENCE 15
1.2 VARIABILITY AND UNCERTAINTY 16
1.3 CHARACTERIZATION VS. MODELING 18
1.4 MODEL TO HARDWARE MATCHING 19
1.5 DESIGN FOR MANUFACTURABILITY VS. STATISTICAL DESIGN 19
Part I Sources of Variability 22
2 FRONT END VARIABILITY 23
2.1 INTRODUCTION 23
2.2 VARIABILITY OF GATE LENGTH 27
2.3 GATE WIDTH VARIABILITY 38
2.4 THRESHOLD VOLTAGE VARIABILITY 39
2.5 THIN FILM THICKNESS 44
2.6 LATTICE STRESS 47
2.7 VARIABILITY IN EMERGING DEVICES 49
2.8 PHYSICAL VARIATIONS DUE TO AGING AND WEAROUT 51
2.9 SUMMARY 53
3 BACK END VARIABILITY 54
3.1 INTRODUCTION 54
3.2 COPPER CMP 55
3.3 COPPER ELECTROPLATING 59
3.4 MULTILEVEL COPPER INTERCONNECT VARIATION 61
3.5 INTERCONNECT LITHOGRAPHY AND ETCH VARIATION 63
3.6 DIELECTRIC VARIATION 65
3.7 BARRIER METAL DEPOSITION 65
3.8 COPPER AND VIA RESISTIVITY 66
3.9 COPPER LINE EDGE ROUGHNESS 67
3.10 CARBON NANOTUBE INTERCONNECTS 68
3.11 SUMMARY 68
4 ENVIRONMENTAL VARIABILITY 69
4.1 INTRODUCTION 69
4.2 IMPACT OF ENVIRONMENTAL VARIABILITY 70
4.3 ANALYSIS OF VOLTAGE VARIABILITY 76
Current 79
4.4 SYSTEMATIC ANALYSIS OF TEMPERATURE VARIABILITY 84
4.5 OTHER SOURCES OF VARIABILITY 92
4.6 SUMMARY 92
Part II Variability Characterization and Analysis 93
5 TEST STRUCTURES FOR VARIABILITY 94
5.1 TEST STRUCTURES: CLASSIFICATION AND FIGURES OF MERIT 94
5.2 CHARACTERIZATION USING SHORT LOOP FLOWS 96
5.3 TRANSISTOR TEST STRUCTURES 101
5.4 DIGITAL TEST STRUCTURES 103
5.5 SUMMARY 107
6 STATISTICAL FOUNDATIONS OF DATA ANALYSIS AND MODELING 109
6.1 A BRIEF PROBABILITY PRIMER 110
6.2 EMPIRICAL MOMENT ESTIMATION 112
6.3 ANALYSIS OF VARIANCE AND ADDITIVE MODELS 114
6.4 CASE STUDIES: ANOVA FOR GATE LENGTH VARIABILITY 117
6.5 DECOMPOSITION OF VARIANCE INTO SPATIAL SIGNATURES 121
6.6 SPATIAL STATISTICS: DATA ANALYSIS AND MODELING 126
6.7 SUMMARY 130
Part III Design Techniques for Systematic Manufacturability Problems 132
7 LITHOGRAPHY ENHANCEMENT TECHNIQUES 133
7.1 FUNDAMENTALS OF LITHOGRAPHY 134
7.2 PROCESS WINDOW ANALYSIS 140
7.3 OPTICAL PROXIMITY CORRECTION AND SRAFS 143
7.4 SUBRESOLUTION ASSIST FEATURES 146
7.5 PHASE SHIFT MASKING 149
7.6 NON-CONVENTIONAL ILLUMINATION AND IMPACT ON DESIGN 155
7.7 NOMINAL AND ACROSS PROCESS WINDOW HOT SPOT ANALYSIS 156
7.8 TIMING ANALYSIS UNDER SYSTEMATIC VARIABILITY 158
7.9 SUMMARY 160
8 ENSURING INTERCONNECT PLANARITY 161
8.1 OVERVIEW OF DUMMY FILL 163
8.2 DUMMY FILL CONCEPT 164
8.3 ALGORITHMS FOR METAL FILL 166
X 167
Y 167
8.4 DUMMY FILL FOR STI CMP AND OTHER PROCESSES 169
8.5 SUMMARY 170
Part IV Statistical Circuit Design 171
9 STATISTICAL CIRCUIT ANALYSIS 172
9.1 CIRCUIT PARAMETERIZATION AND SIMULATION 172
9.2 WORST CASE ANALYSIS 185
9.3 STATISTICAL CIRCUIT ANALYSIS 195
9.4 SUMMARY 204
10 STATISTICAL STATIC TIMING ANALYSIS 206
10.1 BASICS OF STATIC TIMING ANALYSIS 207
10.2 IMPACT OF VARIABILITY ON TRADITIONAL STATIC TIMING VERIFICATION 210
10.3 STATISTICAL TIMING EVALUATION 216
10.4 STATISTICAL GATE LIBRARY CHARACTERIZATION 239
10.5 SUMMARY 242
11 LEAKAGE VARIABILITY AND JOINT PARAMETRIC YIELD 243
11.1 LEAKAGE VARIABILITY MODELING 243
11.2 JOINT POWER AND TIMING PARAMETRIC YIELD ESTIMATION 247
11.3 SUMMARY 253
12 PARAMETRIC YIELD OPTIMIZATION 255
12.1 LIMITATIONS OF TRADITIONAL OPTIMIZATION FOR YIELD IMPROVEMENT 255
12.2 STATISTICAL TIMING YIELD OPTIMIZATION 261
12.3 TECHNIQUES FOR TIMING AND POWER YIELD IMPROVEMENT 272
12.4 SUMMARY 281
13 CONCLUSIONS 282
On semiconductor physics and technology 282
On lithography and reticle enhancement techniques 283
On circuit simulation 283
On timing analysis 283
On design for yield 283
A APPENDIX: PROJECTING VARIABILITY 284
Methodology of Predictions 285
Decomposition into Spatial Scales 287
How to Interpret and Use the Roadmap 288
Projecting CD Variability: A Case Study 289
References 293
Index 311