Spintronics

Discover the latest advances in spintronic materials, devices, and applications

In Spintronics: Materials, Devices and Applications, a team of distinguished researchers delivers a holistic introduction to spintronic effects within cutting-edge materials and applications. Containing the perfect balance of academic research and practical application, the book discusses the potential--and the key limitations and challenges--of spintronic devices.

The latest title in the Wiley Series in Materials for Electronic and Optoelectronic Applications, Spintronics: Materials, Devices and Applications explores giant magneto-resistance (GMR) and tunneling magnetic resistance (TMR) materials, spin-transfer torque and spin-orbit torque materials, spin oscillators, and spin materials for use in artificial neural networks. Applications in multi-ferroelectric and antiferromagnetic materials are presented as well.

This book also includes:

• A thorough introduction to recent research developments in the fields of spintronic materials, devices, and applications
• Comprehensive explorations of skymions, magnetic semiconductors, and antiferromagnetic materials
• Practical discussions of spin-transfer torque materials and devices for magnetic random-access memory
• In-depth examinations of giant magneto-resistance materials and devices for magnetic sensors

Perfect for advanced students and researchers in materials science, physics, electronics, and computer science, Spintronics: Materials, Devices and Applications will also earn a place in the libraries of professionals working in the manufacture of optics, photonics, and nanometrology equipment.

Auteur

Edited by

Kaiyou Wang is Director of State Key Laboratory of Superlattices & Microstructure, Institute of Semiconductors, Chinese Academy of Sciences, Beijing, China. Meiyin Yang is Professor at the Key Laboratory of Microelectronic Devices & Integrated Technology, Institute of Microelectronics of Chinese Academy of Sciences, Beijing, China. Jun Luo is Professor at the Key Laboratory of Microelectronic Devices & Integrated Technology, Institute of Microelectronics of Chinese Academy of Sciences, Beijing, China. Series Editors Arthur Willoughby University of Southampton, Southampton, UK Peter Capper Ex-Leonardo M. W. Ltd, Southampton, UK Safa Kasap University of Saskatchewan, Saskatoon, Canada

Résumé
Discover the latest advances in spintronic materials, devices, and applications In Spintronics: Materials, Devices and Applications, a team of distinguished researchers delivers a holistic introduction to spintronic effects within cutting-edge materials and applications. Containing the perfect balance of academic research and practical application, the book discusses the potential--and the key limitations and challenges--of spintronic devices. The latest title in the Wiley Series in Materials for Electronic and Optoelectronic Applications, Spintronics: Materials, Devices and Applications explores giant magneto-resistance (GMR) and tunneling magnetic resistance (TMR) materials, spin-transfer torque and spin-orbit torque materials, spin oscillators, and spin materials for use in artificial neural networks. Applications in multi-ferroelectric and antiferromagnetic materials are presented as well. This book also includes: A thorough introduction to recent research developments in the fields of spintronic materials, devices, and applications Comprehensive explorations of skymions, magnetic semiconductors, and antiferromagnetic materials Practical discussions of spin-transfer torque materials and devices for magnetic random-access memory In-depth examinations of giant magneto-resistance materials and devices for magnetic sensors Perfect for advanced students and researchers in materials science, physics, electronics, and computer science, Spintronics: Materials, Devices and Applications will also earn a place in the libraries of professionals working in the manufacture of optics, photonics, and nanometrology equipment.

Contenu

List of Contributors xi

Series Preface xiii

Preface xv

1 Introduction 1
Kaiyou Wang

2 Giant Magnetoresistance (GMR) Materials and Devices for Biomedical and Industrial Applications 3
Kai Wu, Diqing Su, Renata Saha, and Jian-Ping Wang

2.1 Introduction 3

2.2 Giant Magnetoresistance (GMR) Effect 4

2.3 Different Types of GMR Sensors 7

2.3.1 Rigid GMR Sensors 7

2.3.1.1 Long-strip GMR Sensors 7

2.3.1.2 Large-area GMR Sensors 8

2.3.2 Flexible GMR Sensors 9

2.3.3 Printable GMR Sensors 11

2.3.4 Granular GMR Sensors (Thin Film- and Solution-based) 11

2.4 GMR Sensors: Surface Modification and Auxiliary Tools 12

2.4.1 GMR Sensor Surface Modification for Biomedical Applications 12

2.4.2 Integration of a Magnetic Flux Concentrator (MFC) 14

2.4.2.1 Superconducting MFC 14

2.4.2.2 Soft-ferromagnetic Material-based MFC 14

2.4.3 Integration of Microfluidic Channels 16

2.5 GMR-based Biomedical Applications 16

2.5.1 GMR-based Immunoassays 16

2.5.1.1 Wash-free and Non-wash-free Immunoassays 17

2.5.1.2 Different Immunoassay Methods 17

2.5.1.3 GMR for Disease Diagnosis 19

2.5.1.4 GMR-based Point-of-Care (POC) Devices 24

2.5.2 GMR-based Genotyping 25

2.5.3 GMR-based Bio-magnetic Field Recording 28

2.5.4 GMR-based Food and Drug Safety Supervision 32

2.6 GMR-based Industrial Applications 34

2.6.1 GMR for Position Sensing 34

2.6.2 GMR for Current Sensing 35

2.6.3 GMR for Material Defect Inspection 37

2.7 Conclusions and Outlook 39

References 40

3 Tunneling Magnetoresistance (TMR) Materials and Devices for Magnetic Sensors 51
Zitong Zhou, Kun Zhang, and Qunwen Leng

3.1 Principle of Tunneling Magnetoresistance Effect 52

3.1.1 Tunneling Process 52

3.1.2 Spin-dependent Tunneling Process 53

3.1.3 The Julliére Model 54

3.1.4 Typical Structure of the Magnetic Sensing Unit 56

3.2 Material and Process 56

3.2.1 TMR Barrier Materials 56

3.2.2 Ferromagnetic Layers in TMR 59

3.2.3 TMR Film Stack 61

3.2.4 Perpendicular Magnetic Anisotropy (PMA) in TMR 65

3.2.5 Material Fabrication and Pattern Process 65

3.2.5.1 Magnetron Sputtering 66

3.2.5.2 Ion Beam Deposition (IBD) 67

3.2.5.3 Evaporation 67

3.2.5.4 Chemical Vapor Deposition (CVD) 67

3.2.5.5 Photolithography 69

3.2.5.6 Etching 69

3.3 The Noise of TMR Sensors 70

3.3.1 The Source of Noise from TMR Sensors 70

3.3.2 Methods to Suppress the Noise 72

3.3.2.1 Increase the Number of MTJs in TMR Device 72

3.3.2.2 Optimize Free Layer Volume 73

3.3.2.3 Flux Concentrator 73

3.3.2.4 Applying a Bias Magnetic Field 74

3.4 TMR Sensors and Applications 75

3.4.1 TMR Read Heads 75

3.4.2 The TMR Angle Sensors 76

3.4.3 Geomagnetic Measurement 79

3.4.4 Spin-MEMS Combined Application 80

3.4.5 Nondestructive Testing (NDT) 82

3.4.6 Ultra-low Magnetic Field Detection: Biosensor 83

3.5 Conclusion 85

References 86

4 Spin-Transfer Torque Materials and Devices for Magnetic Random-Access Memory (STT-MRAM) 93
Yan Cui and Jun Luo

4.1 The Background and Mechanism of STT-MRAM 93

4.1.1 The Background of STT-MRAM 93

4.1.2 The Mechanism of STT-MRAM 93

4.1.2.1 LLGS Equation 93

4.1.2.2 The Write Mechanism of STT-MRAM 94

4.1.2.3 The Magnetism of STT-MTJ 97

4.1.2.4 The Switching Properties of STT-MTJ 99

4.2 The Integrated Process of STT-MRAM 102

4.2.1 CMP Technology 102

4.2.2 Magnetic Film Deposition Technology 103

4.2.3 Photolithography Technology 103

4.2.4 Etching Technology 103

4.2.5 Dielectric Isolation Technology 104

4.2.6 Contact Technology 104

4.2.7 Passivation Deposition 104

4.3 Testing of the STT-MTJ Device 105

4.4 The Development Status of STT-MRAM 105

References 107

**5 Spin-Orbit Torque (SOT) Materials and Devices 113…