Carbon Nanotube Electronics (eBook)

Carbon Nanotube Electronics 2
Preface 6
Contents 8
Contributors 10
Ch-1 Band Structure and Electron Transport Physics of One-Dimensional SWNTs 12
1.1 Introduction to the Band Structures of SWNTs 12
1.1.1 Electronic Band Structure of Graphene 12
1.1.2 Band Structure of SWNT from Graphene 17
1.1.3 Deviation from Simple Zone-Folding Tight-Binding Picture 20
1.1.4 Density of States in SWNTs 20
1.1.5 Experimental Verifications of the Band Structure of SWNTs 21
1.2 Quantum Transport in SWNTs 26
1.2.1 Quantum Conductance in 1D Systems 26
1.2.2 Quantum Transport in SWNTs 27
1.3 Modifications to the Band Structure 32
1.3.1 External Fields 32
1.3.2 Mechanical Deformation 36
1.4 Electron Transport Properties of SWNTs 40
1.4.1 Scatterings in SWNTs 40
1.4.2 Carrier Mobility in SWNTs 45
1.5 Summary 47
Ch-2 Direct Synthesis and Integration of SWNT Devices 54
2.1 Introduction 54
2.2 CVD Synthesis 55
2.2.1 The Method 55
2.2.2 Direct Incorporation with the Device Fabrication Process 56
2.2.3 SWNT Synthesis on Metal Electrodes 57
2.2.4 Lowering the Synthesis Temperature 58
2.3 Controlling the SWNT Growth 59
2.3.1 Location 59
2.3.2 Orientation 61
2.3.3 Chirality 63
2.3.3.1 Narrowing the Diameter Distributions 63
2.3.3.2 Chirality Distribution Analysis for Different CVD Processes 64
2.3.3.3 Selective Removal of the Metallic Nanotubes in FET Devices 66
2.4 Integration 68
2.5 Summary 68
Ch-3 Carbon Nanotube Field-Effect Transistors 73
3.1 Introduction 73
3.2 Schottky Barrier Heights of Metal S/D Contacts 74
3.3 High- Gate Dielectric Integration 80
3.4 Quantum Capacitance 82
3.5 Chemical Doping 83
3.6 Hysteresis and Device Passivation 84
3.7 Near Ideal, Metal-Contacted MOSFETs 86
3.8 SWNT MOSFETs 89
3.9 SWNT BTBT-FETs 91
3.10 Conclusion 92
Ch-4 Measuring the AC Response of SWNT-FETs 97
4.1 Introduction 97
4.2 Assessing the AC Response of Top-Gated SWNT-FETs 99
4.2.1 Power Measurement Using a Spectrum Analyzer 99
4.2.2 Homodyne Detection Using SWNT-FETs 100
4.2.3 RF Characterization Using a Two-Tone Measurement 101
4.3 AC Gain from a SWNT-FET Common Source Amplifier 103
4.3.1 Measurement Approach 103
4.3.2 Fabrication 104
4.3.3 DC Characterization 105
4.3.4 AC Characterization 106
4.3.5 Modeling 109
4.4 Conclusions 113
Ch-5 Device Simulation of SWNT-FETs 117
5.1 Introduction 117
5.2 SWNT-FET Simulation Using NEGF Approach 117
5.2.1 The NEGF Formalism 118
5.2.2 SWNT-FET Simulation in a Real Space Basis Set 119
5.2.3 SWNT-FET Simulation in a Mode Space Basis Set 120
5.2.4 Treatment of Metal--SWNT Contacts 121
5.3 Device Characteristics at the Ballistic Limit 121
5.4 Role of Phonon Scattering 125
5.5 High-Frequency Performance Limits 129
5.6 Optoelectronic Phenomena 133
5.7 Summary 136
Ch-6 Carbon Nanotube Device Modeling and Circuit Simulation 142
6.1 Introduction 142
6.2 Schottky Barrier SWNT-FET Modeling 142
6.2.1 The Ballistic Model 143
6.2.2 Modeling the Schottky Barriers 145
6.2.3 Schottky Barrier Device Characteristics 149
6.2.4 Mixed-Mode Simulations 150
6.3 Compact Model for Circuit Simulation 151
6.3.1 Overview of Carbon Nanotube Transistor Compact Model 152
6.3.2 Model of the Intrinsic SWNT Channel Region (SWNT-FET_L1) 154
6.3.3 The Full SWNT-FET Model 158
6.3.4 Validation of the SWNT Compact Model 163
6.3.5 Applications of the SWNT-FET Compact Model 166
6.4 Summary 169
Ch-7 Performance Modeling for Carbon Nanotube Interconnects 172
7.1 Introduction 172
7.2 Circuit Models for SWNTs 173
7.2.1 Kinetic Inductance 173
7.2.2 Capacitance 175
7.2.3 Resistance 176
7.2.4 Equivalent Circuit 177
7.3 Circuit Models for SWNTBundles 180
7.3.1 Conductivity 180
7.3.2 Capacitance 181
7.3.3 Inductance 183
7.4 Circuit Models for MWNTs 184
7.4.1 Number of Conduction Channels per Shell 185
7.4.2 Total Conductance 186
7.4.3 Inductance and Capacitance 189
7.5 Carbon Nanotube Interconnects 189
7.5.1 Local Interconnects 189
7.5.2 Global Interconnects 194
7.6 Conclusions 196
Ch-8 Chemical Sensing with SWNT FETs 200
8.1 Introduction 200
8.2 Source of Conductance Change 201
8.2.1 Schottky Barrier Modulation Due to Gas Adsorption 202
8.2.2 Charge Transfer to Nanotube 204
8.3 Modeling Gas Adsorption 204
8.4 Application to Data 206
8.4.1 Contributions from the Metal Contact Versus the Channel 206
8.4.2 Partially Exposed Devices 208
8.4.3 Transient Response 210
8.4.4 Surface Binding 212
8.5 Additional Aspects of SWNT FET Sensors 212
8.5.1 Response Time 213
8.5.2 Chemical Specificity 214
8.5.3 Sensitivity 214
8.5.4 Recovery 215
8.5.5 Capacitance-Based Sensing 215
8.6 Summary 215
Ch-9 Single0Walled Carbon Nanotubes for High Performance Thin Film Electronics 219
9.1 Introduction and Motivation 219
9.2 Film Formation Techniques 220
9.2.1 Solution Deposition Methods 221
9.2.1.1 Solution Casting via Controlled Flocculation 221
9.2.1.2 Printing Solution-Cast SWNT from a Stamp 222
9.2.2 Chemical Vapor Deposition Growth 224
9.2.2.1 Unguided Growth on Amorphous Substrates 225
9.2.2.2 Guided Growth on Certain Crystal Substrates 225
9.3 Physical Properties and Device Physics 228
9.3.1 Conducting Films of SWNTs 228
9.3.2 Semiconducting Films 229
9.3.3 Capacitance Coupling in SWNT TFTs 231
9.3.4 Control of Electronic Properties 232
9.3.4.1 Selective Removal, Functionalization of Metallic Tubes 233
9.3.4.2 Chemical Modification of Transport 233
9.3.5 Mechanical and Optical Properties 235
9.4 Devices and Circuits 236
9.4.1 Materials and Processing 237
9.4.1.1 Transfer Techniques 237
9.4.1.2 Dielectrics 238
9.4.1.3 Contacts 239
9.4.2 Transistors Based on SWNT Networks 241
9.4.3 Transistors Based on SWNT Arrays 242
9.4.4 Inverters and Logic Gates 245
9.5 Outlook and Conclusions 246
Ch-10 Circuits, Applications and Outlook 255
10.1 Introduction 255
10.2 Nanotubes for Digital Electronics 255
10.2.1 Scaling of FETs 255
10.2.2 The Potential of Nanotube Transistors 259
10.2.3 SWNT-FET Design Considerations for Digital Circuits 260
10.3 Other Applications and Exploratory Products 265
10.4 Challenges 266
10.5 Conclusions 267
Index 271