Contents Preface xiii 1 Introduction 1 1.1 Why do we need three-dimensional integration? 1 1.2 Book Summary 2 1.3 Performance of digital and biological systems 6 1.3.1 System performance constraints 9 References 11 2 Three-dimensional structures D G Crawley and M Forshaw University College London 13 2.1 Introduction 13 2.2 Parallel processing—simulation of the visual cortex 14 2.3 3D architectural considerations 19 2.3.1 Local Activity Control 20 2.3.2 Quantitative investigation of power reduction 23 2.3.3 SIMD implementation in 3D systems 28 2.3.4 Fault tolerance 30 2.4 3D-CORTEX system specification 33 2.4.1 The interlayer data transfer rate 33 2.4.2 MIMD memory latency and bandwidth 37 2.5 Experimental setup 40 References 41 3 Overview of three-dimensional systems and thermal considerations DG Crawley University College London 43 3.1 Introduction 43 3.2 Three-dimensional techniques 44 3.2.1 Three-dimensional multi-chip modules 44 3.2.2 Stacked chips using connections at the edges of chips 45 3.2.3 Three-dimensional integrated circuit fabrication 46 3.2.4 Stacked chips using connections across the area of chips 46 3.2.5 Three-dimensional computing structures 49 3.3 Thermal aspects of 3D systems 50 3.3.1 Technological approaches 50 3.3.2 Architectural approaches 52 3.4 Conclusions 53 References 53 4 Nanoelectronic devices KNikoli?c and M Forshaw University College London 55 4.1 Introduction 55 4.2 Current status of CMOS 57 4.3 New FET-like devices 59 4.3.1 Carbon nanotubes 59 4.3.2 Organic molecules 61 4.3.3 Nanowires 61 4.3.4 Molecular electromechanical devices 62 4.4 Resonant tunnelling devices 62 4.4.1 Theory and circuit simulation 63 4.4.2 Memory 64 4.4.3 Logic 64 4.5 Single-electron tunnelling (SET) devices 65 4.5.1 Theory 66 4.5.2 Simulation 66 4.5.3 Devices and circuits 68 4.5.4 Memory 70 4.5.5 Logic 71 4.6 Other switching or memory device concepts 72 4.6.1 Magnetoelectronics 72 4.6.2 Quantum interference transistors (QITs) 73 4.6.3 Molecular switches 74 4.7 Quantum cellular automata (QCA) 75 4.7.1 Electronic QCA 75 4.7.2 Magnetic QCA 79 4.7.3 Rapid single-flux quantum devices 82 4.7.4 Josephson junction persistent current bit devices 82 4.8 Discussion and conclusion 83 References 85 5 Molecular electronics R Stadler and M Forshaw University College London 90 5.1 Introduction 90 5.2 Electron transport through single organic molecules 92 5.2.1 Electron transport theory 92 © IOP Publishing Ltd 2005 Contents vii 5.2.2 Scanning probe measurements and mechanically controlled break junctions 96 5.2.3 Possible applications of single organic molecules as various components in electrical circuits 99 5.3 Nanotubes, nanowires and C60 molecules as active transistor elements 100 5.3.1 Carbon nanotube field effect transistors (CNTFETs) 100 5.3.2 Cross-junctions of nanowires or nanotubes 103 5.3.3 A memory/adder model based on an electromechanical single molecule C60 transistor 105 5.4 Molecular films as active elements in regular metallic grids 109 5.4.1 Molecular switches in the junctions of metallic crossbar arrays 110 5.4.2 High-density integration of memory cells and complex circuits 111 5.5 Summary and outlook 113 References 114 6 Nanoimprint lithography: A competitive fabrication technique towards nanodevices Alicia P Kam and Clivia M Sotomayor Torres Institute of Materials Science and Department of Electrical and Information Engineering, University of Wuppertal, Germany 118 6.1 Introduction 118 6.2 Nanoimprint lithography 120 6.2.1 Fabrication issues 122 6.2.2 Instrumentation 123 6.3 Device applications 125 6.3.1 Magnetism 127 6.3.2 Optoelectronics 128 6.3.3 Organic semiconductors 129 6.4 Polymer photonic devices 131 6.4.1 Integrated passive optical devices 131 6.4.2 Organic photonic crystals 132 6.5 Conclusion 132 Acknowledgments 133 References 133 7 Carbon nanotubes interconnects B O Bo?skovi?c and J Robertson Department of Engineering, Cambridge University 139 7.1 Introduction 139 7.2 Synthesis of CNTs 141 7.3 Carbon nanotube properties 147 7.3.1 Electrical properties 147