Transparent Oxide Electronics

Elvira Fortunato is Associate Professor and Director of Institute for Nanotechnologies, Nanomaterials and Nanosciences at the New University of Lisbon. She is one of the inventors of paper transistors and paper memory and was one of the pioneers of European research on thin-film transistors based on oxide semiconductors. She has been Associate Editor of Rapid Research Letters Physica Status Solidi since November 2006 and is the recipient of several awards, including the award for Scientific Excellence from the Portuguese Science Foundation (2005). She is the author of more than 200 papers and has been an invited speaker at MRS, E-MRS and NAIST. Coauthors at CENIMAT, New University of Lisbon: Rodrigo Ferrão de Paiva Martins, Luís Pereira, Pedro Barquinha.

• Preface xiiiAcknowledgments xv1 Introduction 11.1 Oxides and Transparent Electronics: Fundamental Research or Heading Towards Commercial Products? 11.2 The Need for Transparent (Semi)Conductors 31.3 Reaching Full Transparency: Dielectrics and Substrates 5References 62 N-type Transparent Semiconducting Oxides 92.1 Introduction: Binary and Multicomponent Oxides 92.1.1 Binary Compounds: the Examples of Zinc Oxide and Indium Oxide 92.1.2 Ternary and Quaternary Compounds: the Examples of Indium-Zinc Oxide and Gallium-Indium-Zinc Oxide 122.2 Sputtered n-TSOs: Gallium-Indium-Zinc Oxide System 162.2.1 Dependence of the Growth Rate on Oxygen Content in the Ar+O2 Mixture and Target Composition 162.2.2 Structural and Morphological Properties 182.2.3 Electrical Properties 222.2.4 Optical Properties 412.3 Sputtered n-TSOs: Gallium-Zinc-Tin Oxide System 492.4 Solution-Processed n-TSOs 512.4.1 ZTO by Spray-pyrolysis 512.4.2 ZTO by Sol-gel Spin-coating 522.4.3 GIZO Sol-gel by Spin-coating 52References 553 P-type Transparent Conductors and Semiconductors 633.1 Introduction 633.2 P-type Transparent Conductive Oxides 643.3 Thin Film Copper Oxide Semiconductors 663.3.1 Role of Oxygen in the Structure, Electrical and Optical Performance 703.4 Thin Film Tin Oxide Semiconductors 753.4.1 Structure, Composition and Morphology of Tin Oxide Films 783.4.2 Electrical and Optical Properties of Tin Oxide Films 84References 944 Gate Dielectrics in Oxide Electronics 1014.1 Introduction 1014.2 High-k Dielectrics: Why Not? 1024.3 Requirements 1034.4 High-k Dielectrics Deposition 1064.5 Sputtered High-k Dielectrics in Oxide TFTs 1064.6 Hafnium Oxide 1074.6.1 Multicomponent Co-sputtered HfO2 Based Dielectrics 1174.6.2 Multicomponent Dielectrics from Single Target 1264.7 Tantalum Oxide (Ta2O5) 1304.7.1 Multicomponent Ta2O5 Based Dielectrics 1334.8 Multilayer Dielectrics 1384.9 High-k Dielectrics/Oxide Semiconductors Interface 1414.10 Summary 146References 1475 The (R)evolution of Thin-Film Transistors (TFTs) 1555.1 Introduction: Device Operation, History and Main Semiconductor Technologies 1555.1.1 Device Structure and Operation 1555.1.2 Brief History of TFTs 1615.1.3 Comparative Overview of Dominant TFT Technologies 1685.2 Fabrication and Characterization of Oxide TFTs 1705.2.1 N-type GIZO TFTs by Physical Vapor Deposition 1715.2.2 N-type GZTO TFTs by Physical Vapor Deposition 1875.2.3 N-type Oxide TFTs by Solution Processing 1895.2.4 P-type Oxide TFTs by Physical Vapor Deposition 1935.2.5 N-type GIZO TFTs with Sputtered Dielectrics 196References 2026 Electronics With and On Paper 2116.1 Introduction 2116.2 Paper in Electronics 2126.3 Paper Properties 2146.3.1 Structure, Morphology and Thermal Properties 2146.3.2 Electrical Properties of the Paper 2186.4 Resistivity Behaviour of Transparent Conductive Oxides Deposited on Paper 2236.5 Paper Transistors 2256.5.1 Current Transport in Paper Transistors 2286.6 Floating Gate Non-volatile Paper Memory Transistor 2306.6.1 Memory Paper Device Feasibility and Stability 2336.6.2 Memory Selective and Charge Retention Time Behaviors 2346.7 Complementary Metal Oxide Semiconductor Circuits With and On Paper – Paper CMOS 2376.7.1 Capacitance-Voltage and Current-Voltage Characteristics of N/P-Type Paper Transistors 2406.7.2 N- and P-channel Paper FET Operation 2436.7.3 CMOS Inverter Working Principles 2446.7.4 Paper CMOS Performance 2466.8 Solid State Paper Batteries 2496.9 Electrochromic Paper Transistors 2526.10 Paper UV Light Sensors 255References 2567 A Glance at Current and Upcoming Applications 2677.1 Introduction: Emerging Areas for (Non-)transparent Electronics Based on Oxide Semiconductors 2677.2 Active Matrices for Displays 2687.2.1 Display Market Overview and Future Trends 2687.2.2 Driving Schemes and TFT Requirements for LCD and OLED Displays 2697.2.3 Displays with Oxide-Based Backplanes 2717.3 Transparent Circuits 2737.3.1 Inverters and Ring Oscillators 2737.3.2 The Introduction of Oxide CMOS 2757.4 Oxide Semiconductor Heterojunctions 2787.4.1 Oxide Semiconductor Heterojunctions in the Literature 2787.4.2 GIZO Heterojunctions Fabricated at CENIMAT 2797.5 Field Effect Biosensors 2807.5.1 Device Types and Working Principles 2807.5.2 Oxide-Based Biosensors Fabricated at CENIMAT 281References 284Index 287