NANO-ELECTRO-MECHANICAL SWITCH (NEMS) FOR ULTRA-LOW POWER PORTABLE EMBEDDED SYSTEM APPLICATIONS: ANALYSIS, DESIGN, MODELING, AND CIRCUIT SIMULATION

xxii Chapter 1 : I NTRODUCTION . 1 1.1. MOTIVIATION . 1 1.2. THESIS OVERVIEW . 4 Chapter 2 : CMOS TECHNOLOGY SCALING AND LIMITATIONS . 8 INTRODUCTION . 8 2.1. SCALING CMOS TECHNOLOGY . 8 2.2. TRADITIONAL CMOS SCALING . 9 2.2.1. ADVANTAGES OF TRADITIONAL SCALING . 10 2.2.1.1. Transistor Density . 10 2.2.1.2. Performance . 11 2.2.1.3. Dynamic Power . 12 2.2.2. TRADEOFFS OF TRADITIONAL SCALING . 15 2.2.2.1. Physical Perspective . 16 2.2.2.2. Device Perspective . 17 2.2.2.3. Circuit Perspective . 25 2.3. NEW TRENDS IN CMOS TECHNOLOGY . 29 2.3.1.CIRCUIT TECHNIQUES . 30 2.3.1.1. Power Dissipation: Issues & Circuit Techniques . 30 2.3.2. DEVICE OPTIMIZATION TECHNIQUES . 33 2.4. FUTURE TECHNOLOGY TRENDS USING EMERGING TECHNOLOGIES . 34 SUMMARY . 36 Chapter 3 : MEMS/NEMS BACKGROUND . 37 INTRODUCTION . 37 3.1. MEMS/NEM TECHNOLOGY . 37 3.2. MEMS VERSUS NEMS . 38 3.2.1. CHARACTERSTICS . 38 3.2.2. PHYSICS . 39 3.2.3. MANUFACTURING . 40 3.2.3.1. TOP DOWN APPROACH (FABRICATED) . 40 3.2.3.2. BOTTOM-UP APPROACH (SYNTHESIZED) . 41 3.3. NEMS STRCTURES . 41 3.4. MEMS/NEMS OPERATION MODES . 42 3.4.1. SWITCHING MODE (QUASI-STATIC) . 43 3.4.1.1. Capacitive Switch . 43 3.4.1.2. Ohmic Contact Switch (Resistive Switch) . 43 3.4.2. RESONANT MODE (ACOUSTIC) . 44 3.5. MEMS/NEMS PHYSICAL ACTUATION PRINCIPLES . 44 3.6. MEMS/ NEMS MATERIALS . 46 3.7. MEMS/NEMS COMPUTATIONS . 46 Chapter 4 : LITERATURE REVIEW . 48 INTRODUCTION . 48 4.1. ELECTROSTATIC MECHANICAL SWITCHES . 48 4.2. ELECTROSTATIC MECHANICAL SWITCHES AS AN EMERGINIG TECHNOLOGY . 49 4.3. LITERATURE REVIEW . 50 4.3.1. ACTIVE PART‘S MATERIAL . 58 4.3.2. FABRICATION APPROACHES . 58 4.3.3. VALIDATION/EVALUATION . 59 4.3. KEY CRITERIA TO CONSIDER NEMS SWITCHES AS AN EMERGING TECHNOLOGY . 62 Chapter 5 : ELECTROSTATIC NEMS SWITCHES: CONCEPTS, ANALYSIS, AND DESIGN . 67 INTRODUCTION . 67 5.1. PRINCIPLE OF OPERATION . 67 5.2. MULTI-PHYSICS DEVICE . 68 5.3. NEMS PHYSICAL QUANTITIES . 70 5.4. NEMS PHYSICAL PHENOMENA . 70 5.4.1 ELASTIC FORCE . 71 5.4.2. ELECTROSTATIC FORCE . 71 5.4.3. INTERMOLECULAR FORCES . 72 5.4. 4. CONTACT FORCE . 73 5.4. 4.1. Elastic Deformation . 74 5.4. 4.2. Plastic Deformation . 75 5.4. 4.3. Elastic-Plastic Deformation . 75 5.4. 5. DAMPING FORCE . 76 5.4. 5.1. Viscous Damping . 77 5.4. 5.2. Compression Damping . 78 5.4. 6. KINETIC FORCE . 79 5.4. 7. CONTACT BOUNCING MOTION PHENOMENA . 79 5.5. NEMS CHARACTERSTICS . 79 5.5.1. PULL-IN AND PULL-OUT VOLTAGES . 79 5.5.2. SWITCHNIG TIME . 81 5.5.3. ON AND OFF RESISTANCES . 82 5. 5.3.1. OFF Resistance . 82 5.5.3.2. ON Resistance . 83 5.5.4. RELIABILITY ISSUES . 85 5.5.4.1. Stiction . 86 5.5.4.2. Wear . 88 5.6. NEMS PRODUCTION PROCESS . 90 5.7. NEMS SWITCH DESIGN PHASE . 92 5.7. 1. NEMS SWITCH DESIGN: OBJECTIVE AND DECISION . 92 5.7. 2. NEMS DESIGN APPROACHES . 93 5.7. 3. NEMS DESIGN STEPS USING THE FEA SIMULATION TOOL . 95 Chapter 6 : FABRICATED TWO-TERMINAL TUNING FORK NEMS SWITCH . 100 INTRODUCTION . 100 6.1. TWO-TERMINAL TUNING FORK (Ni-Ni) NEMS SWITCH . 101 6.2. TWO-TERMINAL TUNIG FORK NEMS SWITCH FABRICATION . 102 6.3. DEVICE CHARACTERSTICS . 104 6.3.1. OPERATION VOLTAGE . 105 3.2. LEAKAGE CURRENT . 106 6.3.3. ON RESISTANCE . 107 6.3.4. SWITCHNIG SPEED . 107 6.3.5. FOOTPRINT SIZE . 108 6.3.6. SWITCH LIFE TIME . 109 6.4. 3D FEA PHYSICAL DEVICE MODEL . 109 6.5. VERIFICATION . 113 6.6. DEVICE MACROMODLE (CIRCUIT SIMULATION MODEL) . 114 6.6.1. MECHANICAL LUMPED MODEL . 114 6.6.2. ELECTRICAL CIRUIT MODEL . 116 6.6.2.1. Electrical circuit model in the Switching/OFF state . 116 6.6.2.2. Electrical Circuit Model in the ON state . 117 SUMMARY .