Yue Kuo is Life Chair Professor in the Photonics Department of National Yang Ming Chiao Tung University. Hideo Hosono is an honorary and institute professor of Tokyo Institute of Technology. Michael S. Shur is Patricia W. and C. Sheldon Roberts Professor of Solid State Electronics at Rensselaer Polytechnic Institute. Jin Jang is a Chair Professor in the Department of Information Display of Kyung Hee University.

• Preface ix1 Introduction of Metal Oxide Thin Film Transistors 11.1 Progress of Thin Film Transistor Development 11.2 Progress of Metal Oxide Thin Film Transistor Development 31.3 Layout of Book Chapters 5References 62 Semiconductor Materials in Oxide Thin Film Transistor 112.1 Introduction 112.2 Electronic and Crystal Structure of Wide-gap Oxides 112.2.1 Requirements for Semiconductors as Excellent TFT Channel Materials 132.2.2 Electronic Structure of N- and P-type Oxide Semiconductors 142.2.3 Doping Limit and Band Alignment 192.3 Amorphous Oxide Semiconductors for TFT Applications 222.3.1 Amorphous Semiconductors 222.3.2 Transparent Amorphous Oxide Semiconductors 242.3.2.1 Materials Design 242.3.2.2 Characteristic Carrier Transport Properties 292.3.3 Amorphous Oxide Semiconductor TFTs 312.3.4 Electronic States and TFT Operation 352.3.5 Features of Transparent Amorphous Oxide TFTs 372.4 Fundamental Material Issues in High-performance Oxide TFTs 392.4.1 CO Effect on Mobility and Stability of Oxide TFTs 392.4.2 Oxide Composition Effect on P-channel TFT Performance 432.4.3 Role of Hydrogen Impurity on Oxide TFT Characteristics 462.4.3.1 State and Concentration of Hydrogen 462.4.3.2 Carrier Generation and Hydrogen 492.5 Summary 53References 543 Oxide Thin Film Transistor Devices 613.1 Introduction 613.2 Oxide TFT Compared to a-Si, Poly-Si, Organic, and II-VI TFTs 653.3 N-type, P-type, and Ambipolar Oxide TFTs 683.4 Oxide TFT Designs 703.5 Modeling of Oxide TFTs 723.6 Oxide TFT Reliability, Durability, and Stability Under Bias and Light Stress 883.7 Summary 91References 924 Oxide Thin Film Transistor Fabrication Processes 1014.1 Introduction 1014.2 Deposition Methods for Individual Layers in Oxide TFTs 1024.2.1 Process Influences on Individual Layer Material Properties 1024.2.2 Gate Insulators and Passivation Layers for Oxide TFTs 1054.3 Fabrication Processes of Oxide TFTs with Various Structures 1064.3.1 Etch-stop Oxide TFTs 1064.3.2 Back Channel Etch IGZO TFTs 1074.3.3 Coplanar IGZO TFTs 1094.3.4 Dual-gate IGZO TFTs 1094.4 Flexible Substrate Technology for Oxide TFTs 1154.4.1 Flexible Substrates 1154.4.1.1 Fabrication of Polyimide Substrate 1164.4.1.2 Laser Lift-off Detachment of Polyimide Substrate 1164.4.1.3 Mechanical Detachment of Polyimide Substrate 1174.4.2 Flexible IGZO TFTs on PI Substrate 1194.4.3 Highly Flexible Oxide TFTs 1234.5 Solution Process Prepared Oxide TFTs 1264.5.1 Precursors for Semiconductors and Gate Insulators 1264.5.2 Solution-Processed Oxide Semiconductors 1274.5.3 Solution Process Prepared High-k Gate Dielectrics 1304.5.4 Spin-coating Prepared IGZO TFTs 1324.5.5 Spray-pyrolysis Prepared IGZO TFTs 1334.5.6 Inkjet Printed Oxide TFTs 1354.6 Summary 137References 1385 Applications of Oxide Thin Film Transistors 1595.1 Introduction 1595.1.1 Trend in Oxide TFT Applications 1595.1.2 Basic TFT Functions for Applications 1595.2 Oxide TFT Active Matrix Displays 1635.2.1 Liquid Crystal Displays 1645.2.2 Organic Light Emitting Device Displays 1645.2.3 Micro-Light Emitting Device Displays 1665.2.4 Electrophoretic Displays 1675.2.5 Other Types of Displays 1695.3 Oxide TFT Sensors, Sensor Arrays, and Imagers 1695.3.1 pH Sensors 1705.3.2 Gas Sensors 1715.3.2.1 NO 2 Sensors 1715.3.2.2 Humidity Sensors 1735.3.3 Temperature Sensors 1745.3.4 Pressure Sensors 1755.3.5 Bio Sensors 1775.3.6 Photo Sensors and Imagers 1785.3.6.1 UV Sensors 1785.3.6.2 IR and Near-IR Sensors and Imagers 1805.3.6.3 X-ray Imagers 1815.3.6.4 Oxide TFT-IC CMOS Imagers 1835.3.7 Fingerprint Sensors 1855.4 Oxide TFT-Based Circuits 1885.4.1 Additional Oxide TFT Devices for Circuits 1885.4.1.1 P-channel Oxide TFTs 1885.4.1.2 Floating-gate Oxide TFT Memory Devices 1895.4.1.3 Ferroelectric-gate Dielectric Oxide TFT Memory Devices 1905.4.1.4 High Voltage Oxide TFTs 1925.4.2 Inverters and Ring Oscillators 1955.4.3 Memory Circuits 2005.4.4 Display Drivers 2015.4.5 Logic Circuits 2025.4.6 Synapses 2045.5 Oxide TFT Flexible Electronics 2065.5.1 Bending Effect on Oxide TFT Performance 2065.5.2 Bending Effect on Oxide TFT Memory Devices, Circuits, and Others 2095.6 Summary 211References 212Index 227

Yue Kuo is Life Chair Professor in the Photonics Department of National Yang Ming Chiao Tung University. Hideo Hosono is an honorary and institute professor of Tokyo Institute of Technology. Michael S. Shur is Patricia W. and C. Sheldon Roberts Professor of Solid State Electronics at Rensselaer Polytechnic Institute. Jin Jang is a Chair Professor in the Department of Information Display of Kyung Hee University.

• Preface ix1 Introduction of Metal Oxide Thin Film Transistors 11.1 Progress of Thin Film Transistor Development 11.2 Progress of Metal Oxide Thin Film Transistor Development 31.3 Layout of Book Chapters 5References 62 Semiconductor Materials in Oxide Thin Film Transistor 112.1 Introduction 112.2 Electronic and Crystal Structure of Wide-gap Oxides 112.2.1 Requirements for Semiconductors as Excellent TFT Channel Materials 132.2.2 Electronic Structure of N- and P-type Oxide Semiconductors 142.2.3 Doping Limit and Band Alignment 192.3 Amorphous Oxide Semiconductors for TFT Applications 222.3.1 Amorphous Semiconductors 222.3.2 Transparent Amorphous Oxide Semiconductors 242.3.2.1 Materials Design 242.3.2.2 Characteristic Carrier Transport Properties 292.3.3 Amorphous Oxide Semiconductor TFTs 312.3.4 Electronic States and TFT Operation 352.3.5 Features of Transparent Amorphous Oxide TFTs 372.4 Fundamental Material Issues in High-performance Oxide TFTs 392.4.1 CO Effect on Mobility and Stability of Oxide TFTs 392.4.2 Oxide Composition Effect on P-channel TFT Performance 432.4.3 Role of Hydrogen Impurity on Oxide TFT Characteristics 462.4.3.1 State and Concentration of Hydrogen 462.4.3.2 Carrier Generation and Hydrogen 492.5 Summary 53References 543 Oxide Thin Film Transistor Devices 613.1 Introduction 613.2 Oxide TFT Compared to a-Si, Poly-Si, Organic, and II-VI TFTs 653.3 N-type, P-type, and Ambipolar Oxide TFTs 683.4 Oxide TFT Designs 703.5 Modeling of Oxide TFTs 723.6 Oxide TFT Reliability, Durability, and Stability Under Bias and Light Stress 883.7 Summary 91References 924 Oxide Thin Film Transistor Fabrication Processes 1014.1 Introduction 1014.2 Deposition Methods for Individual Layers in Oxide TFTs 1024.2.1 Process Influences on Individual Layer Material Properties 1024.2.2 Gate Insulators and Passivation Layers for Oxide TFTs 1054.3 Fabrication Processes of Oxide TFTs with Various Structures 1064.3.1 Etch-stop Oxide TFTs 1064.3.2 Back Channel Etch IGZO TFTs 1074.3.3 Coplanar IGZO TFTs 1094.3.4 Dual-gate IGZO TFTs 1094.4 Flexible Substrate Technology for Oxide TFTs 1154.4.1 Flexible Substrates 1154.4.1.1 Fabrication of Polyimide Substrate 1164.4.1.2 Laser Lift-off Detachment of Polyimide Substrate 1164.4.1.3 Mechanical Detachment of Polyimide Substrate 1174.4.2 Flexible IGZO TFTs on PI Substrate 1194.4.3 Highly Flexible Oxide TFTs 1234.5 Solution Process Prepared Oxide TFTs 1264.5.1 Precursors for Semiconductors and Gate Insulators 1264.5.2 Solution-Processed Oxide Semiconductors 1274.5.3 Solution Process Prepared High-k Gate Dielectrics 1304.5.4 Spin-coating Prepared IGZO TFTs 1324.5.5 Spray-pyrolysis Prepared IGZO TFTs 1334.5.6 Inkjet Printed Oxide TFTs 1354.6 Summary 137References 1385 Applications of Oxide Thin Film Transistors 1595.1 Introduction 1595.1.1 Trend in Oxide TFT Applications 1595.1.2 Basic TFT Functions for Applications 1595.2 Oxide TFT Active Matrix Displays 1635.2.1 Liquid Crystal Displays 1645.2.2 Organic Light Emitting Device Displays 1645.2.3 Micro-Light Emitting Device Displays 1665.2.4 Electrophoretic Displays 1675.2.5 Other Types of Displays 1695.3 Oxide TFT Sensors, Sensor Arrays, and Imagers 1695.3.1 pH Sensors 1705.3.2 Gas Sensors 1715.3.2.1 NO 2 Sensors 1715.3.2.2 Humidity Sensors 1735.3.3 Temperature Sensors 1745.3.4 Pressure Sensors 1755.3.5 Bio Sensors 1775.3.6 Photo Sensors and Imagers 1785.3.6.1 UV Sensors 1785.3.6.2 IR and Near-IR Sensors and Imagers 1805.3.6.3 X-ray Imagers 1815.3.6.4 Oxide TFT-IC CMOS Imagers 1835.3.7 Fingerprint Sensors 1855.4 Oxide TFT-Based Circuits 1885.4.1 Additional Oxide TFT Devices for Circuits 1885.4.1.1 P-channel Oxide TFTs 1885.4.1.2 Floating-gate Oxide TFT Memory Devices 1895.4.1.3 Ferroelectric-gate Dielectric Oxide TFT Memory Devices 1905.4.1.4 High Voltage Oxide TFTs 1925.4.2 Inverters and Ring Oscillators 1955.4.3 Memory Circuits 2005.4.4 Display Drivers 2015.4.5 Logic Circuits 2025.4.6 Synapses 2045.5 Oxide TFT Flexible Electronics 2065.5.1 Bending Effect on Oxide TFT Performance 2065.5.2 Bending Effect on Oxide TFT Memory Devices, Circuits, and Others 2095.6 Summary 211References 212Index 227

Yue Kuo is Life Chair Professor in the Photonics Department of National Yang Ming Chiao Tung University. Hideo Hosono is an honorary and institute professor of Tokyo Institute of Technology. Michael S. Shur is Patricia W. and C. Sheldon Roberts Professor of Solid State Electronics at Rensselaer Polytechnic Institute. Jin Jang is a Chair Professor in the Department of Information Display of Kyung Hee University.

• Preface ix1 Introduction of Metal Oxide Thin Film Transistors 11.1 Progress of Thin Film Transistor Development 11.2 Progress of Metal Oxide Thin Film Transistor Development 31.3 Layout of Book Chapters 5References 62 Semiconductor Materials in Oxide Thin Film Transistor 112.1 Introduction 112.2 Electronic and Crystal Structure of Wide-gap Oxides 112.2.1 Requirements for Semiconductors as Excellent TFT Channel Materials 132.2.2 Electronic Structure of N- and P-type Oxide Semiconductors 142.2.3 Doping Limit and Band Alignment 192.3 Amorphous Oxide Semiconductors for TFT Applications 222.3.1 Amorphous Semiconductors 222.3.2 Transparent Amorphous Oxide Semiconductors 242.3.2.1 Materials Design 242.3.2.2 Characteristic Carrier Transport Properties 292.3.3 Amorphous Oxide Semiconductor TFTs 312.3.4 Electronic States and TFT Operation 352.3.5 Features of Transparent Amorphous Oxide TFTs 372.4 Fundamental Material Issues in High-performance Oxide TFTs 392.4.1 CO Effect on Mobility and Stability of Oxide TFTs 392.4.2 Oxide Composition Effect on P-channel TFT Performance 432.4.3 Role of Hydrogen Impurity on Oxide TFT Characteristics 462.4.3.1 State and Concentration of Hydrogen 462.4.3.2 Carrier Generation and Hydrogen 492.5 Summary 53References 543 Oxide Thin Film Transistor Devices 613.1 Introduction 613.2 Oxide TFT Compared to a-Si, Poly-Si, Organic, and II-VI TFTs 653.3 N-type, P-type, and Ambipolar Oxide TFTs 683.4 Oxide TFT Designs 703.5 Modeling of Oxide TFTs 723.6 Oxide TFT Reliability, Durability, and Stability Under Bias and Light Stress 883.7 Summary 91References 924 Oxide Thin Film Transistor Fabrication Processes 1014.1 Introduction 1014.2 Deposition Methods for Individual Layers in Oxide TFTs 1024.2.1 Process Influences on Individual Layer Material Properties 1024.2.2 Gate Insulators and Passivation Layers for Oxide TFTs 1054.3 Fabrication Processes of Oxide TFTs with Various Structures 1064.3.1 Etch-stop Oxide TFTs 1064.3.2 Back Channel Etch IGZO TFTs 1074.3.3 Coplanar IGZO TFTs 1094.3.4 Dual-gate IGZO TFTs 1094.4 Flexible Substrate Technology for Oxide TFTs 1154.4.1 Flexible Substrates 1154.4.1.1 Fabrication of Polyimide Substrate 1164.4.1.2 Laser Lift-off Detachment of Polyimide Substrate 1164.4.1.3 Mechanical Detachment of Polyimide Substrate 1174.4.2 Flexible IGZO TFTs on PI Substrate 1194.4.3 Highly Flexible Oxide TFTs 1234.5 Solution Process Prepared Oxide TFTs 1264.5.1 Precursors for Semiconductors and Gate Insulators 1264.5.2 Solution-Processed Oxide Semiconductors 1274.5.3 Solution Process Prepared High-k Gate Dielectrics 1304.5.4 Spin-coating Prepared IGZO TFTs 1324.5.5 Spray-pyrolysis Prepared IGZO TFTs 1334.5.6 Inkjet Printed Oxide TFTs 1354.6 Summary 137References 1385 Applications of Oxide Thin Film Transistors 1595.1 Introduction 1595.1.1 Trend in Oxide TFT Applications 1595.1.2 Basic TFT Functions for Applications 1595.2 Oxide TFT Active Matrix Displays 1635.2.1 Liquid Crystal Displays 1645.2.2 Organic Light Emitting Device Displays 1645.2.3 Micro-Light Emitting Device Displays 1665.2.4 Electrophoretic Displays 1675.2.5 Other Types of Displays 1695.3 Oxide TFT Sensors, Sensor Arrays, and Imagers 1695.3.1 pH Sensors 1705.3.2 Gas Sensors 1715.3.2.1 NO 2 Sensors 1715.3.2.2 Humidity Sensors 1735.3.3 Temperature Sensors 1745.3.4 Pressure Sensors 1755.3.5 Bio Sensors 1775.3.6 Photo Sensors and Imagers 1785.3.6.1 UV Sensors 1785.3.6.2 IR and Near-IR Sensors and Imagers 1805.3.6.3 X-ray Imagers 1815.3.6.4 Oxide TFT-IC CMOS Imagers 1835.3.7 Fingerprint Sensors 1855.4 Oxide TFT-Based Circuits 1885.4.1 Additional Oxide TFT Devices for Circuits 1885.4.1.1 P-channel Oxide TFTs 1885.4.1.2 Floating-gate Oxide TFT Memory Devices 1895.4.1.3 Ferroelectric-gate Dielectric Oxide TFT Memory Devices 1905.4.1.4 High Voltage Oxide TFTs 1925.4.2 Inverters and Ring Oscillators 1955.4.3 Memory Circuits 2005.4.4 Display Drivers 2015.4.5 Logic Circuits 2025.4.6 Synapses 2045.5 Oxide TFT Flexible Electronics 2065.5.1 Bending Effect on Oxide TFT Performance 2065.5.2 Bending Effect on Oxide TFT Memory Devices, Circuits, and Others 2095.6 Summary 211References 212Index 227